release: 0.2.0

Promote [Unreleased] → [0.2.0] in the changelog (M2 UI + M3/M4 + fixes) and
bump the dev-default version to 0.2.0 / 200. The pushed tag drives the released
version per docs/RELEASING.md.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,38 @@ the source of truth for version codes (see Calendula's `docs/RELEASING.md`).
 
 ## [Unreleased]
 
+## [0.2.0] - 2026-06-27
+
+### Added
+- M2 Material 3 Expressive UI — the app is fully navigable now: the
+  provider/permission onboarding gate, the lists overview (smart lists + user
+  lists grouped by account), and the task list (swipe-to-complete / -delete,
+  inline add, smart-list section headers), detail, and create/edit screens, all
+  wired to the M1 ViewModels.
+- M3 detail/edit polish: a "Progress" slider (percent-complete, 5% detents,
+  written to `Tasks.PERCENT_COMPLETE`) and conflict-safe saves — `updateTask`
+  re-checks the provider's `last_modified` against the value captured when the
+  form loaded and surfaces an overwrite-or-cancel prompt instead of clobbering an
+  external change (e.g. a DAVx5 sync).
+- M4 subtasks (UI): reparent — a full-width, searchable "Parent task" sheet on
+  the edit form, with candidates grouped by due-date section, files a task under
+  any active top-level task in its list (or "None" to promote it); switching list
+  clears the now-invalid parent. Tapping a subtask in the detail screen opens its
+  own detail, which shows a "Part of …" parent card. On the task list a parent has
+  a dedicated expand button that reveals its children as a nested grouped run,
+  ending with an inline "add a subtask" row (an opt-out toggle is planned for the
+  M6 settings screen).
+- Priority is coloured by level (green / amber / red pastels) on the list, detail,
+  and edit screens.
+
+### Fixed
+- Overview open-counts now count top-level tasks only, so subtasks — and
+  especially open subtasks under a completed parent — no longer inflate a list's
+  "N open" or the smart-list counts.
+- Swipe-to-delete now reveals its red background + icon as you drag (tracking the
+  live direction, not just the settled target), and a floating "Deleted · Undo"
+  chip defers the actual delete so it can be restored.
+
 ## [0.1.0] - 2026-06-18
 
 ### Added

app/build.gradle.kts

@@ -28,8 +28,8 @@ android {
         // the tag, with versionCode = MAJOR*10000 + MINOR*100 + PATCH
         // (e.g. v2.0.0 -> 20000). These committed values are the dev/local
         // default; keep them matching the latest released tag. See docs/RELEASING.md.
-        versionCode = 100
+        versionCode = 200
-        versionName = "0.1.0"
+        versionName = "0.2.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
@@ -110,6 +110,7 @@ dependencies {
 
     implementation(libs.hilt.android)
     implementation(libs.androidx.hilt.navigation.compose)
+    implementation(libs.androidx.navigation.compose)
     ksp(libs.hilt.compiler)
 
     implementation(libs.androidx.datastore.preferences)

app/src/main/java/de/jeanlucmakiola/floret/data/prefs/SettingsPrefs.kt

@@ -7,6 +7,8 @@ import androidx.datastore.preferences.core.edit
 import androidx.datastore.preferences.core.intPreferencesKey
 import androidx.datastore.preferences.core.longPreferencesKey
 import androidx.datastore.preferences.core.stringPreferencesKey
+import androidx.datastore.preferences.core.stringSetPreferencesKey
+import de.jeanlucmakiola.floret.domain.TaskFormField
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
 import javax.inject.Inject
@@ -21,6 +23,8 @@ data class Settings(
     val defaultListId: Long? = null,
     /** Default minutes before due to remind; 0 = at due time. */
     val reminderLeadMinutes: Int = 0,
+    /** Optional edit-form fields shown by default; the rest sit behind "More fields". */
+    val defaultEditFields: Set<TaskFormField> = emptySet(),
 )
 
 /** App preferences, backed by DataStore. Mirrors Calendula's prefs shape. */
@@ -35,6 +39,9 @@ class SettingsPrefs @Inject constructor(
             dynamicColor = p[DYNAMIC_COLOR] ?: true,
             defaultListId = p[DEFAULT_LIST_ID]?.takeIf { it > 0 },
             reminderLeadMinutes = p[REMINDER_LEAD] ?: 0,
+            defaultEditFields = p[DEFAULT_EDIT_FIELDS].orEmpty()
+                .mapNotNull { name -> runCatching { TaskFormField.valueOf(name) }.getOrNull() }
+                .toSet(),
         )
     }
 
@@ -46,10 +53,15 @@ class SettingsPrefs @Inject constructor(
 
     suspend fun setReminderLeadMinutes(minutes: Int) = dataStore.edit { it[REMINDER_LEAD] = minutes }
 
+    suspend fun setDefaultEditFields(fields: Set<TaskFormField>) = dataStore.edit {
+        it[DEFAULT_EDIT_FIELDS] = fields.mapTo(mutableSetOf()) { field -> field.name }
+    }
+
     private companion object {
         val THEME_MODE = stringPreferencesKey("theme_mode")
         val DYNAMIC_COLOR = booleanPreferencesKey("dynamic_color")
         val DEFAULT_LIST_ID = longPreferencesKey("default_list_id")
         val REMINDER_LEAD = intPreferencesKey("reminder_lead_minutes")
+        val DEFAULT_EDIT_FIELDS = stringSetPreferencesKey("default_edit_fields")
     }
 }

app/src/main/java/de/jeanlucmakiola/floret/data/tasks/Failures.kt

@@ -7,3 +7,10 @@ class ProviderUnavailableException :
 /** A ContentResolver write returned no URI or affected no rows. */
 class TaskWriteFailedException(operation: String) :
     RuntimeException("Task write failed: $operation")
+
+/**
+ * The task changed (e.g. a DAVx5 sync or another app) since the edit form loaded
+ * it, so saving would clobber that change. The UI offers to overwrite or reload.
+ */
+class TaskConflictException(taskId: Long) :
+    RuntimeException("Task $taskId changed since it was loaded")

app/src/main/java/de/jeanlucmakiola/floret/data/tasks/TaskWriteMapper.kt

@@ -17,6 +17,27 @@ object TaskWriteMapper {
         put(Tasks.LIST_ID, form.listId)
         put(Tasks.DESCRIPTION, form.description?.trim()?.ifBlank { null })
         put(Tasks.PRIORITY, form.priority.toICal())
+        // Keep completion in sync with progress whenever the form carries a
+        // percent (the Progress field was used). The provider already auto-
+        // completes at 100% but won't reopen below it — left to itself it strands
+        // a task "done at 75%" — so we set status both ways. COMPLETED is only
+        // cleared on reopen; at 100% we leave it for the provider to fill/keep so
+        // re-saving a finished task doesn't churn its completion timestamp. When
+        // no percent is present the standalone complete toggle stays authoritative.
+        val percent = form.percentComplete?.coerceIn(0, 100)
+        put(Tasks.PERCENT_COMPLETE, percent)
+        when {
+            percent == null -> Unit
+            percent >= 100 -> put(Tasks.STATUS, TasksContract.STATUS_COMPLETED)
+            percent > 0 -> {
+                put(Tasks.STATUS, TasksContract.STATUS_IN_PROCESS)
+                put(Tasks.COMPLETED, null)
+            }
+            else -> {
+                put(Tasks.STATUS, TasksContract.STATUS_NEEDS_ACTION)
+                put(Tasks.COMPLETED, null)
+            }
+        }
         put(Tasks.IS_ALLDAY, if (form.isAllDay) 1 else 0)
         put(Tasks.DTSTART, form.start?.toEpochMilliseconds())
         put(Tasks.DUE, form.due?.toEpochMilliseconds())

app/src/main/java/de/jeanlucmakiola/floret/data/tasks/TasksRepository.kt

@@ -6,6 +6,7 @@ import de.jeanlucmakiola.floret.domain.TaskFilter
 import de.jeanlucmakiola.floret.domain.TaskForm
 import de.jeanlucmakiola.floret.domain.TaskList
 import kotlinx.coroutines.flow.Flow
+import kotlin.time.Instant
 
 /** Whether Floret can use the tasks provider right now. Drives onboarding. */
 enum class ProviderStatus { READY, NEEDS_PERMISSION, NO_PROVIDER }
@@ -21,7 +22,14 @@ interface TasksRepository {
     fun taskDetail(taskId: Long): Flow<TaskDetail?>
 
     suspend fun createTask(form: TaskForm): Long
-    suspend fun updateTask(taskId: Long, form: TaskForm)
+
+    /**
+     * Overwrite [taskId] with [form]. When [expectedLastModified] is non-null, the
+     * task's current `last_modified` is re-checked first and a
+     * [TaskConflictException] is thrown if it differs — i.e. something changed it
+     * since the form loaded. Pass `null` to force the write (overwrite-anyway).
+     */
+    suspend fun updateTask(taskId: Long, form: TaskForm, expectedLastModified: Instant? = null)
     suspend fun setCompleted(taskId: Long, completed: Boolean)
     suspend fun deleteTask(taskId: Long)
     suspend fun createLocalList(name: String, color: Int): Long

app/src/main/java/de/jeanlucmakiola/floret/data/tasks/TasksRepositoryImpl.kt

@@ -2,7 +2,6 @@ package de.jeanlucmakiola.floret.data.tasks
 
 import de.jeanlucmakiola.floret.data.di.IoDispatcher
 import de.jeanlucmakiola.floret.domain.DayWindow
-import de.jeanlucmakiola.floret.domain.SmartList
 import de.jeanlucmakiola.floret.domain.Task
 import de.jeanlucmakiola.floret.domain.TaskDetail
 import de.jeanlucmakiola.floret.domain.TaskFilter
@@ -23,6 +22,7 @@ import java.time.ZoneId
 import javax.inject.Inject
 import javax.inject.Singleton
 import kotlin.time.Clock
+import kotlin.time.Instant
 
 @Singleton
 class TasksRepositoryImpl @Inject constructor(
@@ -37,26 +37,56 @@ class TasksRepositoryImpl @Inject constructor(
 
     override fun taskDetail(taskId: Long): Flow<TaskDetail?> = observing {
         dataSource.task(taskId)?.let { task ->
-            TaskDetail(task, dataSource.subtasks(taskId).filter { it.taskId != taskId })
+            TaskDetail(
+                task = task,
+                subtasks = dataSource.subtasks(taskId).filter { it.taskId != taskId },
+                parent = task.parentId?.takeIf { it > 0 }?.let { dataSource.task(it) },
+            )
         }
     }
 
     private fun loadTasks(filter: TaskFilter): List<Task> {
         val query = when (filter) {
             is TaskFilter.OfList -> TaskQuery(listId = filter.listId, includeCompleted = true)
-            is TaskFilter.Smart -> TaskQuery(includeCompleted = filter.list == SmartList.COMPLETED)
+            // Read completed tasks too, then let [TaskFiltering.matches] enforce each
+            // smart list's own open/closed semantics. We over-read on purpose so a
+            // parent's subtask-progress reflects ALL its children — completed ones
+            // included — even on smart lists that hide completed tasks themselves.
+            is TaskFilter.Smart -> TaskQuery(includeCompleted = true)
         }
         val (todayStart, todayEnd) = DayWindow.today(Clock.System.now(), ZoneId.systemDefault())
-        return dataSource.tasks(query)
+        val all = dataSource.tasks(query)
+        // (done, total) of direct children per parent, over the unfiltered set.
+        val progress: Map<Long, Pair<Int, Int>> = all
+            .filter { (it.parentId ?: 0L) > 0L }
+            .groupingBy { it.parentId!! }
+            .fold(0 to 0) { (done, total), t ->
+                (if (t.isCompleted) done + 1 else done) to (total + 1)
+            }
+        return all
             .filter { TaskFiltering.matches(it, filter, todayStart, todayEnd) }
+            .map { task ->
+                progress[task.taskId]?.let { (done, total) ->
+                    task.copy(subtaskDone = done, subtaskTotal = total)
+                } ?: task
+            }
             .sortedWith(TaskSorting.DEFAULT)
     }
 
     override suspend fun createTask(form: TaskForm): Long =
         withContext(io) { dataSource.insertTask(form) }
 
-    override suspend fun updateTask(taskId: Long, form: TaskForm) =
+    override suspend fun updateTask(taskId: Long, form: TaskForm, expectedLastModified: Instant?) =
-        withContext(io) { dataSource.updateTask(taskId, form) }
+        withContext(io) {
+            // Conflict-safe overwrite: re-read just before writing and bail if the
+            // provider's last_modified moved since the form captured it (external
+            // sync / another app). A null baseline means "force / overwrite anyway".
+            if (expectedLastModified != null) {
+                val current = dataSource.task(taskId)?.lastModified
+                if (current != null && current != expectedLastModified) throw TaskConflictException(taskId)
+            }
+            dataSource.updateTask(taskId, form)
+        }
 
     override suspend fun setCompleted(taskId: Long, completed: Boolean) =
         withContext(io) { dataSource.setCompleted(taskId, completed) }

app/src/main/java/de/jeanlucmakiola/floret/domain/Models.kt

@@ -52,6 +52,13 @@ data class Task(
     val distanceFromCurrent: Int?,
     val created: Instant?,
     val lastModified: Instant?,
+    /**
+     * Direct-subtask progress, filled in by the repository over the *full* task
+     * set so a parent's progress chip counts completed children even on smart
+     * lists that hide them. Both 0 when the task has no subtasks.
+     */
+    val subtaskTotal: Int = 0,
+    val subtaskDone: Int = 0,
 ) {
     val isCompleted: Boolean get() = status == TaskStatus.COMPLETED
     val isClosed: Boolean get() = status == TaskStatus.COMPLETED || status == TaskStatus.CANCELLED
@@ -60,10 +67,11 @@ data class Task(
     val effectiveColor: Int get() = taskColor ?: listColor
 }
 
-/** Detail bundle: a task plus its direct children. */
+/** Detail bundle: a task, its parent (if it's a subtask), and its direct children. */
 data class TaskDetail(
     val task: Task,
     val subtasks: List<Task>,
+    val parent: Task? = null,
 )
 
 // --- pure provider <-> domain value mapping (unit-testable) ------------------

app/src/main/java/de/jeanlucmakiola/floret/domain/TaskForm.kt

@@ -16,6 +16,8 @@ data class TaskForm(
     val isAllDay: Boolean = false,
     val priority: Priority = Priority.NONE,
     val parentId: Long? = null,
+    /** 0..100 progress; `null` leaves it unset (cleared). */
+    val percentComplete: Int? = null,
     /** Minutes before [due] to fire a reminder; `null` = no reminder. */
     val reminderMinutesBeforeDue: Int? = null,
 ) {
@@ -30,3 +32,20 @@ data class TaskForm(
 }
 
 enum class TaskFormError { BLANK_TITLE, NO_LIST, DUE_BEFORE_START, REMINDER_WITHOUT_DUE }
+
+/**
+ * Optional edit-form sections that can be shown or tucked behind "More fields"
+ * (the core Title / List / When are always visible). Which render by default is
+ * a setting; the rest unfold on demand. Declaring these as an enum keeps the
+ * disclosure generic, so adding a field later is one entry plus its card.
+ */
+enum class TaskFormField { Description, Priority, Progress, Parent, Reminder }
+
+/** The optional fields that already carry a value — auto-revealed when editing. */
+fun TaskForm.populatedFields(): Set<TaskFormField> = buildSet {
+    if (!description.isNullOrBlank()) add(TaskFormField.Description)
+    if (priority != Priority.NONE) add(TaskFormField.Priority)
+    if ((percentComplete ?: 0) > 0) add(TaskFormField.Progress)
+    if (parentId != null && parentId > 0) add(TaskFormField.Parent)
+    if (reminderMinutesBeforeDue != null) add(TaskFormField.Reminder)
+}

app/src/main/java/de/jeanlucmakiola/floret/domain/TaskSections.kt

@@ -0,0 +1,39 @@
+package de.jeanlucmakiola.floret.domain
+
+import kotlin.time.Instant
+
+/** A due-date bucket a task list groups its rows under. */
+enum class TaskSection { OVERDUE, TODAY, UPCOMING, NO_DATE, COMPLETED }
+
+/** A non-empty run of tasks under one [TaskSection], already in display order. */
+data class SectionedTasks(val section: TaskSection, val tasks: List<Task>)
+
+/**
+ * Group already-sorted tasks into due-date sections (the standard task-app
+ * presentation). Pure + side-effect-free so it unit-tests with a fixed clock,
+ * mirroring [TaskFiltering] / [DayWindow]. Completed tasks always fall to the
+ * [TaskSection.COMPLETED] bucket regardless of their due date.
+ *
+ * [todayStart] is local midnight today and [todayEnd] local midnight tomorrow
+ * (compute with [DayWindow]). Only non-empty sections are returned, in the
+ * fixed order Overdue → Today → Upcoming → No date → Completed.
+ */
+object TaskSections {
+
+    fun of(tasks: List<Task>, todayStart: Instant, todayEnd: Instant): List<SectionedTasks> {
+        val bySection = tasks.groupBy { sectionOf(it, todayStart, todayEnd) }
+        return TaskSection.entries.mapNotNull { section ->
+            bySection[section]?.takeIf { it.isNotEmpty() }?.let { SectionedTasks(section, it) }
+        }
+    }
+
+    fun sectionOf(task: Task, todayStart: Instant, todayEnd: Instant): TaskSection {
+        if (task.isCompleted) return TaskSection.COMPLETED
+        val due = task.due ?: return TaskSection.NO_DATE
+        return when {
+            due < todayStart -> TaskSection.OVERDUE
+            due < todayEnd -> TaskSection.TODAY
+            else -> TaskSection.UPCOMING
+        }
+    }
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/RootScreen.kt

@@ -19,13 +19,12 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.floret.R
 import de.jeanlucmakiola.floret.data.tasks.ProviderStatus
-import de.jeanlucmakiola.floret.ui.lists.ListsScreen
+import de.jeanlucmakiola.floret.ui.navigation.FloretNavHost
 import de.jeanlucmakiola.floret.ui.permission.PermissionViewModel
 
 /**
- * App root: gates on the tasks-provider permission, then shows the home
+ * App root: gates on the tasks-provider permission, then hands off to
- * ([ListsScreen]). Navigation to the task-list / edit screens is wired as those
+ * [FloretNavHost] (lists → task list → detail / edit).
- * screens land (next milestones); the callbacks are stubs for now.
  */
 @Composable
 fun RootScreen(
@@ -50,11 +49,7 @@ fun RootScreen(
             action = stringResource(R.string.onboarding_permission_button),
             onAction = { launcher.launch(permission.permissionsToRequest.toTypedArray()) },
         )
-        ProviderStatus.READY -> ListsScreen(
+        ProviderStatus.READY -> FloretNavHost(modifier = modifier)
-            modifier = modifier,
-            onOpenFilter = { /* TODO: navigate to TaskListScreen */ },
-            onNewTask = { /* TODO: navigate to TaskEditScreen */ },
-        )
     }
 }
 

app/src/main/java/de/jeanlucmakiola/floret/ui/common/DateTimeField.kt

@@ -0,0 +1,166 @@
+package de.jeanlucmakiola.floret.ui.common
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.rounded.Clear
+import androidx.compose.material.icons.rounded.Event
+import androidx.compose.material3.DatePicker
+import androidx.compose.material3.DatePickerDialog
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.TimePicker
+import androidx.compose.material3.rememberDatePickerState
+import androidx.compose.material3.rememberTimePickerState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.Dialog
+import de.jeanlucmakiola.floret.R
+import java.time.LocalDate
+import java.time.LocalTime
+import java.time.ZoneId
+import java.time.ZoneOffset
+import kotlin.time.Instant
+
+private val zone: ZoneId get() = ZoneId.systemDefault()
+
+internal fun Instant.toLocalDate(): LocalDate =
+    java.time.Instant.ofEpochMilli(toEpochMilliseconds()).atZone(zone).toLocalDate()
+
+internal fun Instant.toLocalTime(): LocalTime =
+    java.time.Instant.ofEpochMilli(toEpochMilliseconds()).atZone(zone).toLocalTime()
+
+internal fun localToInstant(date: LocalDate, time: LocalTime): Instant =
+    Instant.fromEpochMilliseconds(date.atTime(time).atZone(zone).toInstant().toEpochMilli())
+
+/**
+ * A labelled date(-time) field for the edit form: a tonal row showing the
+ * current value (or nothing), tappable to pick a date and — unless [allDay] —
+ * a time. A clear affordance appears once a value is set. Emits `null` when
+ * cleared. Styled to match the app's rounded tonal family.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun DateTimeField(
+    label: String,
+    value: Instant?,
+    allDay: Boolean,
+    onChange: (Instant?) -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    var showDatePicker by remember { mutableStateOf(false) }
+    var showTimePicker by remember { mutableStateOf(false) }
+    var pendingDate by remember { mutableStateOf<LocalDate?>(null) }
+
+    Surface(
+        onClick = { showDatePicker = true },
+        shape = RoundedCornerShape(22.dp),
+        color = MaterialTheme.colorScheme.surfaceContainerHigh,
+        modifier = modifier.fillMaxWidth(),
+    ) {
+        Row(
+            modifier = Modifier.padding(horizontal = 20.dp, vertical = 14.dp),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.spacedBy(12.dp),
+        ) {
+            Icon(Icons.Rounded.Event, contentDescription = null, tint = MaterialTheme.colorScheme.onSurfaceVariant)
+            Column(modifier = Modifier.weight(1f)) {
+                Text(
+                    text = label,
+                    style = MaterialTheme.typography.labelMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                Text(
+                    text = value?.formatDateTime(allDay) ?: stringResource(R.string.edit_set),
+                    style = MaterialTheme.typography.bodyLarge,
+                )
+            }
+            if (value != null) {
+                IconButton(onClick = { onChange(null) }) {
+                    Icon(Icons.Rounded.Clear, contentDescription = stringResource(R.string.edit_clear))
+                }
+            }
+        }
+    }
+
+    if (showDatePicker) {
+        val initialMillis = (value ?: Instant.fromEpochMilliseconds(System.currentTimeMillis()))
+            .toLocalDate().atStartOfDay(ZoneOffset.UTC).toInstant().toEpochMilli()
+        val dateState = rememberDatePickerState(initialSelectedDateMillis = initialMillis)
+        DatePickerDialog(
+            onDismissRequest = { showDatePicker = false },
+            confirmButton = {
+                TextButton(
+                    onClick = {
+                        showDatePicker = false
+                        val millis = dateState.selectedDateMillis ?: return@TextButton
+                        val date = java.time.Instant.ofEpochMilli(millis)
+                            .atZone(ZoneOffset.UTC).toLocalDate()
+                        if (allDay) {
+                            onChange(localToInstant(date, LocalTime.MIDNIGHT))
+                        } else {
+                            pendingDate = date
+                            showTimePicker = true
+                        }
+                    },
+                ) { Text(stringResource(android.R.string.ok)) }
+            },
+            dismissButton = {
+                TextButton(onClick = { showDatePicker = false }) {
+                    Text(stringResource(android.R.string.cancel))
+                }
+            },
+        ) { DatePicker(state = dateState) }
+    }
+
+    if (showTimePicker) {
+        val base = value ?: Instant.fromEpochMilliseconds(System.currentTimeMillis())
+        val timeState = rememberTimePickerState(
+            initialHour = base.toLocalTime().hour,
+            initialMinute = base.toLocalTime().minute,
+        )
+        Dialog(onDismissRequest = { showTimePicker = false }) {
+            Surface(
+                shape = RoundedCornerShape(28.dp),
+                color = MaterialTheme.colorScheme.surfaceContainerHigh,
+            ) {
+                Column(
+                    modifier = Modifier.padding(24.dp),
+                    horizontalAlignment = Alignment.CenterHorizontally,
+                    verticalArrangement = Arrangement.spacedBy(16.dp),
+                ) {
+                    TimePicker(state = timeState)
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.End,
+                    ) {
+                        TextButton(onClick = { showTimePicker = false }) {
+                            Text(stringResource(android.R.string.cancel))
+                        }
+                        TextButton(onClick = {
+                            showTimePicker = false
+                            val date = pendingDate ?: return@TextButton
+                            onChange(localToInstant(date, LocalTime.of(timeState.hour, timeState.minute)))
+                        }) { Text(stringResource(android.R.string.ok)) }
+                    }
+                }
+            }
+        }
+    }
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/common/DateTimeFormat.kt

@@ -0,0 +1,28 @@
+package de.jeanlucmakiola.floret.ui.common
+
+import java.time.ZoneId
+import java.time.format.DateTimeFormatter
+import java.time.format.FormatStyle
+import kotlin.time.Instant
+
+/**
+ * Locale-aware display formatting for the [kotlin.time.Instant]s the domain
+ * uses. Kept tiny and dependency-free; the data layer stores instants, the UI
+ * renders them in the device's zone and locale.
+ */
+private val dateFormatter: DateTimeFormatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM)
+private val timeFormatter: DateTimeFormatter = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT)
+
+private fun Instant.atSystemZone() =
+    java.time.Instant.ofEpochMilli(toEpochMilliseconds())
+        .atZone(ZoneId.systemDefault())
+
+/** Medium localized date, e.g. "18 Jun 2026". */
+fun Instant.formatDate(): String = atSystemZone().format(dateFormatter)
+
+/** Short localized time, e.g. "14:30". */
+fun Instant.formatTime(): String = atSystemZone().format(timeFormatter)
+
+/** Date alone for all-day items, otherwise date + time. */
+fun Instant.formatDateTime(allDay: Boolean): String =
+    if (allDay) formatDate() else "${formatDate()} · ${formatTime()}"

app/src/main/java/de/jeanlucmakiola/floret/ui/common/GroupedList.kt

@@ -18,6 +18,7 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.Shape
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 
@@ -36,10 +37,51 @@ fun positionOf(index: Int, count: Int): Position = when {
     else -> Position.Middle
 }
 
+/** Corner radii for a grouped segment: full at the group's outer edges, small between. */
+fun groupedShape(position: Position, full: Dp, small: Dp): Shape = when (position) {
+    Position.Alone -> RoundedCornerShape(full)
+    Position.Top -> RoundedCornerShape(topStart = full, topEnd = full, bottomStart = small, bottomEnd = small)
+    Position.Middle -> RoundedCornerShape(small)
+    Position.Bottom -> RoundedCornerShape(topStart = small, topEnd = small, bottomStart = full, bottomEnd = full)
+}
+
 /**
- * One row in a grouped list: an M3 [ListItem] over a tonal [Surface] whose
+ * One segment of a grouped list: a tonal [Surface] whose corner radii come from
- * corner radii come from its [position] (so a run of rows reads as a single
+ * [position] (so a run reads as a single rounded card), with a small gap below
- * rounded card). Corners morph further on press — the expressive shape play.
+ * all but the last. Corners morph rounder on press — the expressive shape play.
+ * The caller supplies [content] and any horizontal inset via [modifier], so the
+ * same primitive serves both the 16dp-inset lists and full-width detail cards.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun GroupedSurface(
+    position: Position,
+    modifier: Modifier = Modifier,
+    onClick: (() -> Unit)? = null,
+    color: Color = MaterialTheme.colorScheme.surfaceContainerHigh,
+    content: @Composable () -> Unit,
+) {
+    val interaction = remember { MutableInteractionSource() }
+    val pressed by interaction.collectIsPressedAsState()
+    val full by animateDpAsState(if (pressed) 36.dp else 22.dp, label = "fullCorner")
+    val small by animateDpAsState(if (pressed) 36.dp else 6.dp, label = "smallCorner")
+    val shape = groupedShape(position, full, small)
+    val gap = when (position) {
+        Position.Top, Position.Middle -> Modifier.padding(bottom = 2.dp)
+        Position.Bottom, Position.Alone -> Modifier
+    }
+    val base = modifier.fillMaxWidth().then(gap)
+    if (onClick != null) {
+        Surface(onClick = onClick, color = color, shape = shape, interactionSource = interaction, modifier = base) { content() }
+    } else {
+        Surface(color = color, shape = shape, modifier = base) { content() }
+    }
+}
+
+/**
+ * One row in a grouped list: an M3 [ListItem] over a [GroupedSurface] (the
+ * tonal, position-shaped, press-morphing family container). Insets 16dp like
+ * the lists overview.
  */
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -54,24 +96,6 @@ fun GroupedRow(
     trailing: @Composable (() -> Unit)? = null,
     onClick: (() -> Unit)? = null,
 ) {
-    val interaction = remember { MutableInteractionSource() }
-    val pressed by interaction.collectIsPressedAsState()
-    val full by animateDpAsState(if (pressed) 36.dp else 22.dp, label = "fullCorner")
-    val small by animateDpAsState(if (pressed) 36.dp else 6.dp, label = "smallCorner")
-    val shape = when (position) {
-        Position.Alone -> RoundedCornerShape(full)
-        Position.Top -> RoundedCornerShape(
-            topStart = full, topEnd = full, bottomStart = small, bottomEnd = small,
-        )
-        Position.Middle -> RoundedCornerShape(small)
-        Position.Bottom -> RoundedCornerShape(
-            topStart = small, topEnd = small, bottomStart = full, bottomEnd = full,
-        )
-    }
-    val gap = when (position) {
-        Position.Top, Position.Middle -> Modifier.padding(bottom = 2.dp)
-        Position.Bottom, Position.Alone -> Modifier
-    }
     val itemColors = if (selected) {
         ListItemDefaults.colors(
             containerColor = Color.Transparent,
@@ -83,7 +107,17 @@ fun GroupedRow(
     } else {
         ListItemDefaults.colors(containerColor = Color.Transparent)
     }
-    val item: @Composable () -> Unit = {
+    val containerColor = if (selected) {
+        MaterialTheme.colorScheme.secondaryContainer
+    } else {
+        MaterialTheme.colorScheme.surfaceContainerHigh
+    }
+    GroupedSurface(
+        position = position,
+        modifier = modifier.padding(horizontal = 16.dp),
+        onClick = onClick,
+        color = containerColor,
+    ) {
         ListItem(
             headlineContent = { Text(title) },
             supportingContent = summary?.let { text -> { Text(text) } },
@@ -93,24 +127,4 @@ fun GroupedRow(
             modifier = Modifier.heightIn(min = minHeight),
         )
     }
-    val base = modifier
-        .fillMaxWidth()
-        .padding(horizontal = 16.dp)
-        .then(gap)
-    val containerColor = if (selected) {
-        MaterialTheme.colorScheme.secondaryContainer
-    } else {
-        MaterialTheme.colorScheme.surfaceContainerHigh
-    }
-    if (onClick != null) {
-        Surface(
-            onClick = onClick,
-            color = containerColor,
-            shape = shape,
-            interactionSource = interaction,
-            modifier = base,
-        ) { item() }
-    } else {
-        Surface(color = containerColor, shape = shape, modifier = base) { item() }
-    }
 }

app/src/main/java/de/jeanlucmakiola/floret/ui/common/InlineTextField.kt

@@ -0,0 +1,83 @@
+package de.jeanlucmakiola.floret.ui.common
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.text.BasicTextField
+import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.graphics.isSpecified
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.input.KeyboardCapitalization
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.unit.dp
+
+/**
+ * The app's borderless text input: no underline, no outline, just the tonal
+ * card behind it. Floret uses this inside a tonal [androidx.compose.material3.Surface]
+ * for the edit form (title + cards), so anything that takes text reads as one
+ * family rather than a boxed Material field. Ported from Calendula so the two
+ * apps share one input style.
+ */
+@Composable
+fun InlineTextField(
+    value: String,
+    onValueChange: (String) -> Unit,
+    placeholder: String,
+    modifier: Modifier = Modifier
+        .fillMaxWidth()
+        .padding(vertical = 4.dp),
+    textStyle: TextStyle = MaterialTheme.typography.titleMedium,
+    singleLine: Boolean = true,
+    minLines: Int = 1,
+    keyboardType: KeyboardType = KeyboardType.Text,
+    capitalization: KeyboardCapitalization = KeyboardCapitalization.Sentences,
+    imeAction: ImeAction = ImeAction.Default,
+    /** Invoked when the IME action key (e.g. Done) is pressed. */
+    onImeAction: (() -> Unit)? = null,
+) {
+    val resolvedStyle = textStyle.copy(
+        color = if (textStyle.color.isSpecified) {
+            textStyle.color
+        } else {
+            MaterialTheme.colorScheme.onSurface
+        },
+    )
+    BasicTextField(
+        value = value,
+        onValueChange = onValueChange,
+        textStyle = resolvedStyle,
+        singleLine = singleLine,
+        minLines = minLines,
+        keyboardOptions = KeyboardOptions(
+            keyboardType = keyboardType,
+            capitalization = capitalization,
+            imeAction = imeAction,
+        ),
+        keyboardActions = onImeAction?.let { action ->
+            KeyboardActions(onAny = { action() })
+        } ?: KeyboardActions.Default,
+        cursorBrush = SolidColor(MaterialTheme.colorScheme.primary),
+        decorationBox = { innerTextField ->
+            Box {
+                if (value.isEmpty()) {
+                    // Clearly fainter than typed text, so a hint never reads as
+                    // prefilled content.
+                    Text(
+                        text = placeholder,
+                        style = resolvedStyle,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
+                    )
+                }
+                innerTextField()
+            }
+        },
+        modifier = modifier,
+    )
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/common/ListChip.kt

@@ -3,17 +3,23 @@ package de.jeanlucmakiola.floret.ui.common
 import androidx.compose.foundation.background
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Checklist
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.luminance
+import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 
 /**
@@ -53,3 +59,25 @@ fun ListColorChip(color: Int, modifier: Modifier = Modifier) {
         )
     }
 }
+
+/**
+ * A small pill naming the task's list, filled in the list's (pastelised) colour.
+ * The label flips black/white by the fill's luminance so it stays legible on any
+ * hue in light and dark. Used in mixed views (smart lists) where rows span lists.
+ */
+@Composable
+fun ListNameChip(name: String, color: Int, modifier: Modifier = Modifier) {
+    val dark = isSystemInDarkTheme()
+    val fill = pastelize(color, dark)
+    val onFill = if (fill.luminance() > 0.5f) Color.Black else Color.White
+    Surface(color = fill, shape = RoundedCornerShape(50), modifier = modifier) {
+        Text(
+            text = name,
+            color = onFill,
+            style = MaterialTheme.typography.labelSmall,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+            modifier = Modifier.padding(horizontal = 8.dp, vertical = 2.dp),
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/common/OptionCard.kt

@@ -0,0 +1,95 @@
+package de.jeanlucmakiola.floret.ui.common
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.isSpecified
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.unit.dp
+
+/**
+ * The app's standard pick in a selection dialog: a full-width tonal card,
+ * optionally with a leading icon and a supporting line; the selected option is
+ * highlighted. Stack with 8dp gaps inside an AlertDialog — the only sanctioned
+ * selection-modal style (no radio rows, no bare text lists). Ported from
+ * Calendula so the families' dialogs read identically.
+ */
+@Composable
+fun OptionCard(
+    label: String,
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier,
+    icon: ImageVector? = null,
+    /** Icon tint override, e.g. a list colour; unspecified follows selection. */
+    iconTint: Color = Color.Unspecified,
+    supportingText: String? = null,
+    selected: Boolean = false,
+    /** Label colour override, e.g. primary for an emphasised entry. */
+    labelColor: Color = Color.Unspecified,
+) {
+    val contentColor = if (selected) {
+        MaterialTheme.colorScheme.onSecondaryContainer
+    } else {
+        MaterialTheme.colorScheme.onSurface
+    }
+    Surface(
+        onClick = onClick,
+        color = if (selected) {
+            MaterialTheme.colorScheme.secondaryContainer
+        } else {
+            MaterialTheme.colorScheme.surfaceContainerHighest
+        },
+        shape = RoundedCornerShape(12.dp),
+        modifier = modifier.fillMaxWidth(),
+    ) {
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 14.dp),
+        ) {
+            if (icon != null) {
+                Icon(
+                    imageVector = icon,
+                    contentDescription = null,
+                    tint = when {
+                        iconTint.isSpecified -> iconTint
+                        selected -> MaterialTheme.colorScheme.onSecondaryContainer
+                        else -> MaterialTheme.colorScheme.onSurfaceVariant
+                    },
+                    modifier = Modifier.size(20.dp),
+                )
+                Spacer(Modifier.width(12.dp))
+            }
+            Column {
+                Text(
+                    text = label,
+                    style = MaterialTheme.typography.titleMedium,
+                    color = if (labelColor.isSpecified) labelColor else contentColor,
+                )
+                if (supportingText != null) {
+                    Text(
+                        text = supportingText,
+                        style = MaterialTheme.typography.bodySmall,
+                        color = if (selected) {
+                            MaterialTheme.colorScheme.onSecondaryContainer.copy(alpha = 0.8f)
+                        } else {
+                            MaterialTheme.colorScheme.onSurfaceVariant
+                        },
+                    )
+                }
+            }
+        }
+    }
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/common/PriorityChip.kt

@@ -0,0 +1,109 @@
+package de.jeanlucmakiola.floret.ui.common
+
+import androidx.compose.foundation.BorderStroke
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.rounded.Flag
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.isSpecified
+import androidx.compose.ui.graphics.luminance
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.floret.domain.Priority
+
+/**
+ * Priority has no semantic Material role (M3 only ships `error` for danger), so
+ * we give the ranked levels their own hues — green / amber / red. They're softened
+ * harder than the list-colour [pastelize] (lower saturation, higher value) so the
+ * chips stay gentle and low-key rather than shouting. [Priority.NONE] has no
+ * colour (callers render it neutral).
+ */
+fun priorityFill(priority: Priority, dark: Boolean): Color {
+    val base = when (priority) {
+        Priority.HIGH -> 0xFFE53935.toInt()   // red
+        Priority.MEDIUM -> 0xFFFFB300.toInt() // amber
+        Priority.LOW -> 0xFF43A047.toInt()    // green
+        Priority.NONE -> return Color.Unspecified
+    }
+    val hsv = FloatArray(3)
+    android.graphics.Color.colorToHSV(base, hsv)
+    hsv[1] = if (dark) 0.36f else 0.22f // desaturate toward pastel
+    hsv[2] = if (dark) 0.58f else 0.92f // light, soft fill in light; muted in dark
+    return Color(android.graphics.Color.HSVToColor(hsv))
+}
+
+/**
+ * A coloured status pill for a task's priority: a flag plus the level's [label],
+ * filled in that level's pastel hue. Used read-only in the list and detail
+ * screens (default [selected] = true), and as a selectable option in the edit
+ * form — there [selected] = false shows the hue on the flag with an outlined,
+ * unfilled container, and tapping commits the choice via [onClick].
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun PriorityChip(
+    priority: Priority,
+    label: String,
+    modifier: Modifier = Modifier,
+    selected: Boolean = true,
+    showIcon: Boolean = true,
+    onClick: (() -> Unit)? = null,
+) {
+    val dark = isSystemInDarkTheme()
+    val fill = priorityFill(priority, dark)
+    val hasColor = fill.isSpecified
+
+    val container: Color
+    val content: Color
+    val iconTint: Color
+    var border: BorderStroke? = null
+    when {
+        selected && hasColor -> {
+            container = fill
+            content = if (fill.luminance() > 0.5f) Color.Black else Color.White
+            iconTint = content
+        }
+        selected -> { // NONE, selected — neutral fill, no hue to show
+            container = MaterialTheme.colorScheme.surfaceContainerHighest
+            content = MaterialTheme.colorScheme.onSurfaceVariant
+            iconTint = content
+        }
+        else -> { // an unselected option in a picker — outline, hue kept on the flag
+            container = Color.Transparent
+            content = MaterialTheme.colorScheme.onSurfaceVariant
+            iconTint = if (hasColor) fill else MaterialTheme.colorScheme.onSurfaceVariant
+            border = BorderStroke(1.dp, MaterialTheme.colorScheme.outlineVariant)
+        }
+    }
+
+    val body: @Composable () -> Unit = {
+        Row(
+            modifier = Modifier.padding(horizontal = 10.dp, vertical = 5.dp),
+            horizontalArrangement = Arrangement.spacedBy(4.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            if (showIcon) {
+                Icon(Icons.Rounded.Flag, contentDescription = null, tint = iconTint, modifier = Modifier.size(15.dp))
+            }
+            Text(label, style = MaterialTheme.typography.labelMedium, color = content)
+        }
+    }
+    val shape = RoundedCornerShape(50)
+    if (onClick != null) {
+        Surface(onClick = onClick, color = container, shape = shape, border = border, modifier = modifier) { body() }
+    } else {
+        Surface(color = container, shape = shape, border = border, modifier = modifier) { body() }
+    }
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/detail/TaskDetailScreen.kt

@@ -0,0 +1,528 @@
+package de.jeanlucmakiola.floret.ui.detail
+
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.foundation.background
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.text.BasicTextField
+import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ColumnScope
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.imePadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.rounded.ArrowBack
+import androidx.compose.material.icons.automirrored.rounded.ListAlt
+import androidx.compose.material.icons.automirrored.rounded.Notes
+import androidx.compose.material.icons.rounded.AccountTree
+import androidx.compose.material.icons.rounded.Add
+import androidx.compose.material.icons.rounded.Check
+import androidx.compose.material.icons.rounded.Checklist
+import androidx.compose.material.icons.rounded.Delete
+import androidx.compose.material.icons.rounded.Edit
+import androidx.compose.material.icons.rounded.ExpandMore
+import androidx.compose.material.icons.rounded.Flag
+import androidx.compose.material.icons.rounded.Percent
+import androidx.compose.material.icons.rounded.Schedule
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.LinearProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.floret.R
+import de.jeanlucmakiola.floret.domain.Task
+import de.jeanlucmakiola.floret.domain.TaskDetail
+import de.jeanlucmakiola.floret.ui.common.GroupedSurface
+import de.jeanlucmakiola.floret.ui.common.PriorityChip
+import de.jeanlucmakiola.floret.ui.common.formatDate
+import de.jeanlucmakiola.floret.ui.common.formatTime
+import de.jeanlucmakiola.floret.ui.common.pastelize
+import de.jeanlucmakiola.floret.ui.common.positionOf
+import de.jeanlucmakiola.floret.ui.tasklist.priorityLabel
+
+/**
+ * One task's detail. Each fact is its own tonal card with a leading icon (the
+ * Calendula detail pattern); only genuinely-grouped things — the subtasks — use
+ * the grouped-row run. Edit / delete live in the top bar.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun TaskDetailScreen(
+    onEdit: () -> Unit,
+    onDeleted: () -> Unit,
+    onBack: () -> Unit,
+    onOpenTask: (Long) -> Unit,
+    modifier: Modifier = Modifier,
+    viewModel: TaskDetailViewModel = hiltViewModel(),
+) {
+    val state by viewModel.state.collectAsStateWithLifecycle()
+
+    Scaffold(
+        modifier = modifier,
+        topBar = {
+            TopAppBar(
+                title = { Text(stringResource(R.string.task_detail_title)) },
+                navigationIcon = {
+                    IconButton(onClick = onBack) {
+                        Icon(
+                            Icons.AutoMirrored.Rounded.ArrowBack,
+                            contentDescription = stringResource(R.string.back),
+                        )
+                    }
+                },
+                actions = {
+                    val content = state as? TaskDetailUiState.Content
+                    IconButton(onClick = onEdit, enabled = content != null) {
+                        Icon(Icons.Rounded.Edit, contentDescription = stringResource(R.string.edit))
+                    }
+                    IconButton(
+                        onClick = {
+                            content?.let {
+                                viewModel.delete(it.detail.task)
+                                onDeleted()
+                            }
+                        },
+                        enabled = content != null,
+                    ) {
+                        Icon(Icons.Rounded.Delete, contentDescription = stringResource(R.string.delete))
+                    }
+                },
+            )
+        },
+    ) { inner ->
+        when (val s = state) {
+            TaskDetailUiState.Loading -> Unit
+            TaskDetailUiState.NotFound ->
+                CenteredMessage(stringResource(R.string.task_detail_not_found), inner)
+            is TaskDetailUiState.Content -> DetailBody(
+                detail = s.detail,
+                inner = inner,
+                onToggle = { viewModel.toggleComplete(s.detail.task) },
+                onToggleSubtask = { viewModel.toggleComplete(it) },
+                onAddSubtask = { viewModel.addSubtask(it) },
+                onOpenTask = onOpenTask,
+            )
+        }
+    }
+}
+
+@Composable
+private fun DetailBody(
+    detail: TaskDetail,
+    inner: androidx.compose.foundation.layout.PaddingValues,
+    onToggle: () -> Unit,
+    onToggleSubtask: (Task) -> Unit,
+    onAddSubtask: (String) -> Unit,
+    onOpenTask: (Long) -> Unit,
+) {
+    val task = detail.task
+    val dark = isSystemInDarkTheme()
+    val accent = pastelize(task.effectiveColor, dark)
+    val gap = 12.dp
+    var subtasksExpanded by rememberSaveable { mutableStateOf(true) }
+
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .padding(inner)
+            // Shrink the scroll viewport by the keyboard so the focused add-subtask
+            // field scrolls into view above the IME instead of being hidden.
+            .imePadding()
+            .verticalScroll(rememberScrollState())
+            .padding(start = 24.dp, end = 24.dp, top = 8.dp, bottom = 40.dp),
+    ) {
+        // Title + complete toggle, with a short list-coloured accent beneath.
+        Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+            Checkbox(checked = task.isCompleted, onCheckedChange = { onToggle() })
+            Text(
+                text = task.title.ifBlank { stringResource(R.string.task_untitled) },
+                style = MaterialTheme.typography.headlineMedium,
+                fontWeight = FontWeight.SemiBold,
+                textDecoration = if (task.isCompleted) TextDecoration.LineThrough else null,
+                modifier = Modifier.weight(1f),
+            )
+        }
+        Spacer(Modifier.height(10.dp))
+        Box(
+            modifier = Modifier
+                .width(48.dp)
+                .height(3.dp)
+                .background(accent, RoundedCornerShape(2.dp)),
+        )
+
+        Spacer(Modifier.height(20.dp))
+
+        // One card per fact; gaps between, no shared container (they aren't a group).
+        val cards = buildList<@Composable () -> Unit> {
+            // Parent — only when this is a subtask. Conveys that it's filed under
+            // another task (and so doesn't stand alone in the list); taps open it.
+            detail.parent?.let { parent ->
+                add {
+                    DetailCard(
+                        icon = Icons.Rounded.AccountTree,
+                        iconContentDescription = stringResource(R.string.detail_parent),
+                        onClick = { onOpenTask(parent.taskId) },
+                    ) {
+                        Text(
+                            text = stringResource(R.string.detail_part_of),
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        )
+                        Text(
+                            text = parent.title.ifBlank { stringResource(R.string.task_untitled) },
+                            style = MaterialTheme.typography.titleMedium,
+                        )
+                    }
+                }
+            }
+
+            // When — the Calendula time card: date primary, time(s) secondary.
+            taskWhenLines(task)?.let { (primary, secondary) ->
+                add {
+                    DetailCard(icon = Icons.Rounded.Schedule, iconContentDescription = stringResource(R.string.detail_due)) {
+                        Text(primary, style = MaterialTheme.typography.titleMedium)
+                        if (secondary != null) {
+                            Spacer(Modifier.height(2.dp))
+                            Text(
+                                secondary,
+                                style = MaterialTheme.typography.bodyMedium,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            )
+                        }
+                    }
+                }
+            }
+
+            // List — icon tinted in the list colour conveys identity (no extra dot).
+            add {
+                DetailCard(
+                    icon = Icons.Rounded.Checklist,
+                    iconTint = accent,
+                    iconContentDescription = stringResource(R.string.detail_list),
+                ) {
+                    Text(
+                        text = task.listName ?: stringResource(R.string.detail_list),
+                        style = MaterialTheme.typography.titleMedium,
+                    )
+                }
+            }
+
+            // Priority — a coloured status chip in the level's hue.
+            if (task.priority != de.jeanlucmakiola.floret.domain.Priority.NONE) {
+                add {
+                    DetailCard(
+                        icon = Icons.Rounded.Flag,
+                        iconContentDescription = stringResource(R.string.detail_priority),
+                    ) {
+                        PriorityChip(
+                            priority = task.priority,
+                            label = priorityLabel(task.priority),
+                            showIcon = false,
+                        )
+                    }
+                }
+            }
+
+            // Progress — shown when the task carries its own percent or has
+            // subtasks (then the completion ratio fills in if no percent is set).
+            val hasSubtasks = detail.subtasks.isNotEmpty()
+            if ((task.percentComplete ?: 0) > 0 || hasSubtasks) {
+                val pct = task.percentComplete
+                    ?: (detail.subtasks.count { it.isCompleted } * 100 / detail.subtasks.size)
+                add {
+                    DetailCard(icon = Icons.Rounded.Percent, iconContentDescription = stringResource(R.string.detail_progress)) {
+                        Row(modifier = Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.SpaceBetween) {
+                            Text(stringResource(R.string.detail_progress), style = MaterialTheme.typography.titleMedium)
+                            Text(
+                                stringResource(R.string.percent_complete, pct),
+                                style = MaterialTheme.typography.titleMedium,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            )
+                        }
+                        Spacer(Modifier.height(8.dp))
+                        LinearProgressIndicator(progress = { pct / 100f }, modifier = Modifier.fillMaxWidth())
+                    }
+                }
+            }
+
+            // Description.
+            task.description?.takeIf { it.isNotBlank() }?.let { description ->
+                add {
+                    DetailCard(icon = Icons.AutoMirrored.Rounded.Notes, iconContentDescription = null) {
+                        Text(description, style = MaterialTheme.typography.bodyMedium)
+                    }
+                }
+            }
+
+            // Subtasks — a genuine group: a connected grouped run whose first
+            // segment is the expand/collapse toggle. Always shown (even with no
+            // subtasks yet) so the add field is reachable on any task.
+            add {
+                SubtasksGroup(
+                    subtasks = detail.subtasks,
+                    expanded = subtasksExpanded,
+                    onToggle = { subtasksExpanded = !subtasksExpanded },
+                    onToggleSubtask = onToggleSubtask,
+                    onAddSubtask = onAddSubtask,
+                    onOpenSubtask = onOpenTask,
+                )
+            }
+        }
+        cards.forEachIndexed { index, card ->
+            if (index > 0) Spacer(Modifier.height(gap))
+            card()
+        }
+    }
+}
+
+/**
+ * Subtasks as a connected grouped run (the GroupedRow family look) at the
+ * cards' width: the first segment is the expand/collapse toggle (icon,
+ * "Subtasks", a done/total count, chevron); the rest are the subtask rows.
+ */
+@Composable
+private fun SubtasksGroup(
+    subtasks: List<Task>,
+    expanded: Boolean,
+    onToggle: () -> Unit,
+    onToggleSubtask: (Task) -> Unit,
+    onAddSubtask: (String) -> Unit,
+    onOpenSubtask: (Long) -> Unit,
+) {
+    val done = subtasks.count { it.isCompleted }
+    // Completed subtasks sink to the bottom; stable, so order is otherwise kept.
+    val ordered = remember(subtasks) { subtasks.sortedBy { it.isCompleted } }
+    val rotation by animateFloatAsState(if (expanded) 180f else 0f, label = "subtasksChevron")
+    // Segments when expanded: header + the always-present add row + each subtask.
+    val count = if (expanded) subtasks.size + 2 else 1
+
+    // First segment: the toggle header.
+    GroupedSurface(position = positionOf(0, count), onClick = onToggle) {
+        Row(
+            modifier = Modifier.fillMaxWidth().heightIn(min = 56.dp).padding(horizontal = 16.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Icon(
+                imageVector = Icons.AutoMirrored.Rounded.ListAlt,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.size(24.dp),
+            )
+            Spacer(Modifier.width(16.dp))
+            Text(
+                text = stringResource(R.string.detail_subtasks),
+                style = MaterialTheme.typography.titleMedium,
+                modifier = Modifier.weight(1f),
+            )
+            // No count until there's something to count.
+            if (subtasks.isNotEmpty()) {
+                Text(
+                    text = "$done / ${subtasks.size}",
+                    style = MaterialTheme.typography.labelLarge,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                Spacer(Modifier.width(8.dp))
+            }
+            Icon(
+                imageVector = Icons.Rounded.ExpandMore,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.rotate(rotation),
+            )
+        }
+    }
+
+    if (expanded) {
+        // Always-present add row at the top of the list, in an accent tone.
+        GroupedSurface(
+            position = positionOf(1, count),
+            color = MaterialTheme.colorScheme.primaryContainer,
+        ) {
+            AddSubtaskField(onAdd = onAddSubtask)
+        }
+        ordered.forEachIndexed { index, sub ->
+            GroupedSurface(
+                position = positionOf(index + 2, count),
+                onClick = { onOpenSubtask(sub.taskId) },
+            ) {
+                Row(
+                    modifier = Modifier.fillMaxWidth().heightIn(min = 56.dp).padding(start = 8.dp, end = 16.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    Checkbox(checked = sub.isCompleted, onCheckedChange = { onToggleSubtask(sub) })
+                    Spacer(Modifier.width(4.dp))
+                    Text(
+                        text = sub.title.ifBlank { stringResource(R.string.task_untitled) },
+                        style = MaterialTheme.typography.bodyLarge,
+                        textDecoration = if (sub.isCompleted) TextDecoration.LineThrough else null,
+                        color = if (sub.isCompleted) {
+                            MaterialTheme.colorScheme.onSurfaceVariant
+                        } else {
+                            MaterialTheme.colorScheme.onSurface
+                        },
+                        modifier = Modifier.weight(1f),
+                    )
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Inline "add a subtask" — title only; submits on the tick or the IME action.
+ * A [BasicTextField] (not the boxed Material field) so its text lines up exactly
+ * with the subtask titles, the checkbox column matched by the leading + icon.
+ */
+@Composable
+private fun AddSubtaskField(onAdd: (String) -> Unit) {
+    var text by remember { mutableStateOf("") }
+    fun submit() {
+        if (text.isNotBlank()) {
+            onAdd(text.trim())
+            text = ""
+        }
+    }
+    val accentOn = MaterialTheme.colorScheme.onPrimaryContainer
+    Row(
+        modifier = Modifier.fillMaxWidth().heightIn(min = 56.dp).padding(start = 8.dp, end = 8.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Box(modifier = Modifier.size(48.dp), contentAlignment = Alignment.Center) {
+            Icon(Icons.Rounded.Add, contentDescription = null, tint = accentOn)
+        }
+        Spacer(Modifier.width(4.dp))
+        BasicTextField(
+            value = text,
+            onValueChange = { text = it },
+            singleLine = true,
+            textStyle = MaterialTheme.typography.bodyLarge.copy(color = accentOn),
+            cursorBrush = SolidColor(accentOn),
+            keyboardOptions = KeyboardOptions(imeAction = ImeAction.Done),
+            keyboardActions = KeyboardActions(onDone = { submit() }),
+            modifier = Modifier.weight(1f),
+            decorationBox = { inner ->
+                if (text.isEmpty()) {
+                    Text(
+                        text = stringResource(R.string.add_task_hint),
+                        style = MaterialTheme.typography.bodyLarge,
+                        color = accentOn.copy(alpha = 0.7f),
+                    )
+                }
+                inner()
+            },
+        )
+        if (text.isNotBlank()) {
+            IconButton(onClick = ::submit) {
+                Icon(Icons.Rounded.Check, contentDescription = stringResource(R.string.cd_add_task), tint = accentOn)
+            }
+        }
+    }
+}
+
+/** One info card: tonal container, leading icon in the gutter, value to the right. */
+@Composable
+private fun DetailCard(
+    icon: ImageVector,
+    iconContentDescription: String?,
+    iconTint: Color = MaterialTheme.colorScheme.onSurfaceVariant,
+    onClick: (() -> Unit)? = null,
+    content: @Composable ColumnScope.() -> Unit,
+) {
+    val shape = RoundedCornerShape(16.dp)
+    val color = MaterialTheme.colorScheme.surfaceContainerHigh
+    val body: @Composable () -> Unit = {
+        Row(
+            modifier = Modifier.padding(16.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Icon(
+                imageVector = icon,
+                contentDescription = iconContentDescription,
+                tint = iconTint,
+                modifier = Modifier.size(24.dp),
+            )
+            Spacer(Modifier.width(16.dp))
+            Column(modifier = Modifier.weight(1f), content = content)
+        }
+    }
+    if (onClick != null) {
+        Surface(onClick = onClick, color = color, shape = shape, modifier = Modifier.fillMaxWidth()) { body() }
+    } else {
+        Surface(color = color, shape = shape, modifier = Modifier.fillMaxWidth()) { body() }
+    }
+}
+
+/**
+ * The task's "when", formatted like Calendula's event time card: a primary date
+ * line and an optional secondary time line. A start+due pair reads as a range;
+ * `null` when the task has no dates at all.
+ */
+@Composable
+private fun taskWhenLines(task: Task): Pair<String, String?>? {
+    val start = task.start
+    val due = task.due
+    return when {
+        start != null && due != null -> {
+            val sameDay = start.formatDate() == due.formatDate()
+            val primary = if (sameDay) due.formatDate() else "${start.formatDate()} – ${due.formatDate()}"
+            val secondary = if (task.isAllDay) null else "${start.formatTime()} – ${due.formatTime()}"
+            primary to secondary
+        }
+        due != null -> due.formatDate() to if (task.isAllDay) null else due.formatTime()
+        start != null -> start.formatDate() to if (task.isAllDay) null else start.formatTime()
+        else -> null
+    }
+}
+
+@Composable
+private fun CenteredMessage(text: String, inner: androidx.compose.foundation.layout.PaddingValues) {
+    Box(
+        modifier = Modifier.fillMaxSize().padding(inner).padding(32.dp),
+        contentAlignment = Alignment.Center,
+    ) {
+        Text(
+            text = text,
+            style = MaterialTheme.typography.bodyLarge,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center,
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/detail/TaskDetailViewModel.kt

@@ -6,6 +6,7 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.floret.data.tasks.TasksRepository
 import de.jeanlucmakiola.floret.domain.Task
 import de.jeanlucmakiola.floret.domain.TaskDetail
+import de.jeanlucmakiola.floret.domain.TaskForm
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
@@ -54,4 +55,15 @@ class TaskDetailViewModel @Inject constructor(
     fun delete(task: Task) = viewModelScope.launch {
         runCatching { repository.deleteTask(task.taskId) }
     }
+
+    /** Add a subtask (title only) under the currently-shown task. */
+    fun addSubtask(title: String) = viewModelScope.launch {
+        val parent = (state.value as? TaskDetailUiState.Content)?.detail?.task ?: return@launch
+        if (title.isBlank()) return@launch
+        runCatching {
+            repository.createTask(
+                TaskForm(title = title.trim(), listId = parent.listId, parentId = parent.taskId),
+            )
+        }
+    }
 }

app/src/main/java/de/jeanlucmakiola/floret/ui/edit/TaskEditViewModel.kt

@@ -5,11 +5,16 @@ import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.floret.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.floret.data.reminders.ReminderScheduler
+import de.jeanlucmakiola.floret.data.tasks.TaskConflictException
 import de.jeanlucmakiola.floret.data.tasks.TasksRepository
 import de.jeanlucmakiola.floret.domain.Priority
+import de.jeanlucmakiola.floret.domain.Task
+import de.jeanlucmakiola.floret.domain.TaskFilter
 import de.jeanlucmakiola.floret.domain.TaskForm
 import de.jeanlucmakiola.floret.domain.TaskFormError
+import de.jeanlucmakiola.floret.domain.TaskFormField
 import de.jeanlucmakiola.floret.domain.TaskList
+import de.jeanlucmakiola.floret.domain.populatedFields
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
@@ -34,12 +39,24 @@ data class TaskEditUiState(
     val isAllDay: Boolean = false,
     val priority: Priority = Priority.NONE,
     val parentId: Long? = null,
+    val percentComplete: Int? = null,
     val reminderMinutesBeforeDue: Int? = null,
     val lists: List<TaskList> = emptyList(),
+    /** Top-level tasks in the current list this task can be filed under (reparent). */
+    val parentCandidates: List<Task> = emptyList(),
+    /** Optional sections currently shown (core Title / List / When are always on). */
+    val visibleFields: Set<TaskFormField> = emptySet(),
+    /** Optional sections still tucked behind "More fields". */
+    val hiddenFields: List<TaskFormField> = emptyList(),
     val errors: Set<TaskFormError> = emptySet(),
     val saveFailed: Boolean = false,
+    /** The task changed underneath us; the screen asks to overwrite or cancel. */
+    val saveConflict: Boolean = false,
     val saved: Boolean = false,
-)
+) {
+    /** The currently-selected parent task, if this task is filed under one. */
+    val parent: Task? get() = parentCandidates.firstOrNull { it.taskId == parentId }
+}
 
 @HiltViewModel
 class TaskEditViewModel @Inject constructor(
@@ -53,21 +70,33 @@ class TaskEditViewModel @Inject constructor(
 
     private var editingTaskId: Long? = null
 
+    /** `last_modified` captured when the form loaded — the conflict-check baseline. */
+    private var baselineLastModified: Instant? = null
+
+    /** Sections shown by default (a setting); the rest unfold via [revealField]. */
+    private var defaultFields: Set<TaskFormField> = emptySet()
+
     /** Start a fresh task, optionally pre-selecting a list / parent. */
     fun bindNew(presetListId: Long? = null, parentId: Long? = null) {
         editingTaskId = null
+        baselineLastModified = null
         viewModelScope.launch {
+            val settings = settingsPrefs.settings.first()
+            defaultFields = settings.defaultEditFields
             val lists = runCatching { repository.taskLists().first() }.getOrElse { emptyList() }
             val defaultList = presetListId
-                ?: settingsPrefs.settings.first().defaultListId
+                ?: settings.defaultListId
                 ?: lists.firstOrNull { !it.isLocal }?.id
                 ?: lists.firstOrNull()?.id
-            _state.value = TaskEditUiState(
+            _state.value = withFields(
+                TaskEditUiState(
                     loading = false,
                     isNew = true,
                     listId = defaultList,
                     parentId = parentId,
                     lists = lists,
+                    parentCandidates = loadParents(defaultList, selfId = null),
+                ),
             )
         }
     }
@@ -76,13 +105,16 @@ class TaskEditViewModel @Inject constructor(
     fun bindEdit(taskId: Long) {
         editingTaskId = taskId
         viewModelScope.launch {
+            defaultFields = settingsPrefs.settings.first().defaultEditFields
             val lists = runCatching { repository.taskLists().first() }.getOrElse { emptyList() }
             val task = runCatching { repository.taskDetail(taskId).first()?.task }.getOrNull()
             if (task == null) {
                 _state.value = _state.value.copy(loading = false, lists = lists)
                 return@launch
             }
-            _state.value = TaskEditUiState(
+            baselineLastModified = task.lastModified
+            _state.value = withFields(
+                TaskEditUiState(
                     loading = false,
                     isNew = false,
                     title = task.title,
@@ -93,33 +125,72 @@ class TaskEditViewModel @Inject constructor(
                     isAllDay = task.isAllDay,
                     priority = task.priority,
                     parentId = task.parentId,
+                    percentComplete = task.percentComplete,
                     lists = lists,
+                    parentCandidates = loadParents(task.listId, selfId = taskId),
+                ),
             )
         }
     }
 
+    /**
+     * Tasks the edited task can be filed under: active, top-level tasks in
+     * [listId], minus the task itself (a task can't parent itself). Restricting to
+     * top-level keeps the hierarchy one level deep (matching the detail screen),
+     * and to active so you don't file work under something already done/cancelled.
+     */
+    private suspend fun loadParents(listId: Long?, selfId: Long?): List<Task> {
+        if (listId == null) return emptyList()
+        val tasks = runCatching { repository.tasks(TaskFilter.OfList(listId)).first() }.getOrElse { emptyList() }
+        return tasks.filter { !it.isClosed && !it.isSubtask && it.taskId != selfId }
+    }
+
+    /** Reveal an optional section (one tap from the "More fields" picker). */
+    fun revealField(field: TaskFormField) = update {
+        val visible = it.visibleFields + field
+        it.copy(visibleFields = visible, hiddenFields = hiddenOf(visible))
+    }
+
+    /**
+     * Resolve which optional sections are visible: the default set, plus any
+     * field that already carries a value (so editing never hides real data).
+     */
+    private fun withFields(state: TaskEditUiState): TaskEditUiState {
+        val visible = defaultFields + state.toForm().populatedFields()
+        return state.copy(visibleFields = visible, hiddenFields = hiddenOf(visible))
+    }
+
+    private fun hiddenOf(visible: Set<TaskFormField>): List<TaskFormField> =
+        TaskFormField.entries.filterNot { it in visible }
+
     fun onTitleChange(value: String) = update { it.copy(title = value, errors = emptySet()) }
     fun onDescriptionChange(value: String) = update { it.copy(description = value) }
-    fun onListChange(listId: Long) = update { it.copy(listId = listId, errors = emptySet()) }
+
+    /** Switching list invalidates the parent (it lived in the old list); reload candidates. */
+    fun onListChange(listId: Long) {
+        if (_state.value.listId == listId) return // re-picking the same list keeps the parent
+        update { it.copy(listId = listId, parentId = null, errors = emptySet()) }
+        viewModelScope.launch {
+            val candidates = loadParents(listId, selfId = editingTaskId)
+            update { it.copy(parentCandidates = candidates) }
+        }
+    }
+
     fun onStartChange(value: Instant?) = update { it.copy(start = value) }
     fun onDueChange(value: Instant?) = update { it.copy(due = value) }
     fun onAllDayChange(value: Boolean) = update { it.copy(isAllDay = value) }
     fun onPriorityChange(value: Priority) = update { it.copy(priority = value) }
+    fun onPercentChange(value: Int?) = update { it.copy(percentComplete = value?.coerceIn(0, 100)) }
+    fun onParentChange(parentId: Long?) = update { it.copy(parentId = parentId) }
     fun onReminderChange(minutesBeforeDue: Int?) = update { it.copy(reminderMinutesBeforeDue = minutesBeforeDue) }
 
-    fun save() {
+    /** Dismiss the conflict prompt without saving (the user keeps editing). */
+    fun dismissConflict() = update { it.copy(saveConflict = false) }
+
+    /** [force] = overwrite even if the task changed since it loaded (conflict prompt). */
+    fun save(force: Boolean = false) {
         val current = _state.value
-        val form = TaskForm(
+        val form = current.toForm()
-            title = current.title,
-            listId = current.listId ?: 0L,
-            description = current.description.ifBlank { null },
-            start = current.start,
-            due = current.due,
-            isAllDay = current.isAllDay,
-            priority = current.priority,
-            parentId = current.parentId,
-            reminderMinutesBeforeDue = current.reminderMinutesBeforeDue,
-        )
         val errors = form.validate()
         if (errors.isNotEmpty()) {
             _state.value = current.copy(errors = errors)
@@ -128,12 +199,20 @@ class TaskEditViewModel @Inject constructor(
         viewModelScope.launch {
             runCatching {
                 val id = editingTaskId
-                if (id == null) repository.createTask(form) else repository.updateTask(id, form)
+                if (id == null) {
+                    repository.createTask(form)
+                } else {
+                    repository.updateTask(id, form, expectedLastModified = if (force) null else baselineLastModified)
+                }
                 reminderScheduler.sync()
             }.onSuccess {
-                _state.value = _state.value.copy(saved = true, saveFailed = false)
+                _state.value = _state.value.copy(saved = true, saveFailed = false, saveConflict = false)
-            }.onFailure {
+            }.onFailure { error ->
-                _state.value = _state.value.copy(saveFailed = true)
+                _state.value = if (error is TaskConflictException) {
+                    _state.value.copy(saveConflict = true, saveFailed = false)
+                } else {
+                    _state.value.copy(saveFailed = true)
+                }
             }
         }
     }
@@ -142,3 +221,17 @@ class TaskEditViewModel @Inject constructor(
         _state.value = block(_state.value)
     }
 }
+
+/** Snapshot the editable state as a validated [TaskForm]. */
+private fun TaskEditUiState.toForm(): TaskForm = TaskForm(
+    title = title,
+    listId = listId ?: 0L,
+    description = description.ifBlank { null },
+    start = start,
+    due = due,
+    isAllDay = isAllDay,
+    priority = priority,
+    parentId = parentId,
+    percentComplete = percentComplete,
+    reminderMinutesBeforeDue = reminderMinutesBeforeDue,
+)

app/src/main/java/de/jeanlucmakiola/floret/ui/lists/ListsViewModel.kt

@@ -49,16 +49,20 @@ class ListsViewModel @Inject constructor(
 
     private fun buildContent(lists: List<TaskList>, openTasks: List<Task>): ListsUiState.Content {
         val (todayStart, todayEnd) = DayWindow.today(Clock.System.now(), ZoneId.systemDefault())
+        // Count only top-level tasks: a subtask is represented by its parent (and
+        // its progress chip), and an open subtask under a *completed* parent must
+        // not read as an open item here. Mirrors the task list collapsing subtasks.
+        val topLevel = openTasks.filter { !it.isSubtask }
         fun count(smart: SmartList) =
-            openTasks.count { TaskFiltering.matches(it, TaskFilter.Smart(smart), todayStart, todayEnd) }
+            topLevel.count { TaskFiltering.matches(it, TaskFilter.Smart(smart), todayStart, todayEnd) }
 
         val smartCounts = listOf(
             SmartCount(SmartList.TODAY, count(SmartList.TODAY)),
             SmartCount(SmartList.OVERDUE, count(SmartList.OVERDUE)),
             SmartCount(SmartList.UPCOMING, count(SmartList.UPCOMING)),
-            SmartCount(SmartList.ALL, openTasks.size),
+            SmartCount(SmartList.ALL, topLevel.size),
         )
-        val openByList = openTasks.groupingBy { it.listId }.eachCount()
+        val openByList = topLevel.groupingBy { it.listId }.eachCount()
         val groups = lists
             .groupBy { it.accountName }
             .map { (account, accountLists) ->

app/src/main/java/de/jeanlucmakiola/floret/ui/navigation/Destinations.kt

@@ -0,0 +1,88 @@
+package de.jeanlucmakiola.floret.ui.navigation
+
+import androidx.navigation.NavType
+import androidx.navigation.navArgument
+import de.jeanlucmakiola.floret.domain.SmartList
+import de.jeanlucmakiola.floret.domain.TaskFilter
+
+/**
+ * String-based route table for the app's [androidx.navigation.NavHost].
+ *
+ * Routes are kept stringly-typed (rather than the type-safe `@Serializable`
+ * API) so we don't have to pull in the kotlinx-serialization Gradle plugin for
+ * four small destinations. Each destination exposes a `route` template (for
+ * `composable(...)`) and a builder that fills the arguments (for `navigate`).
+ *
+ * Argument convention: optional `Long`s default to [NO_ID] (`-1`) rather than
+ * being nullable, which sidesteps the lack of a nullable-Long [NavType].
+ */
+object Dest {
+
+    const val NO_ID = -1L
+
+    /** Home — smart lists + the user's lists. */
+    const val LISTS = "lists"
+
+    /**
+     * One [TaskFilter]'s tasks. Carries *either* `listId` (a real list) *or*
+     * `smart` (a [SmartList] name); whichever is set decides the filter.
+     */
+    object TaskList {
+        const val ARG_LIST_ID = "listId"
+        const val ARG_SMART = "smart"
+        const val route = "taskList?$ARG_LIST_ID={$ARG_LIST_ID}&$ARG_SMART={$ARG_SMART}"
+
+        val arguments = listOf(
+            navArgument(ARG_LIST_ID) { type = NavType.LongType; defaultValue = NO_ID },
+            navArgument(ARG_SMART) { type = NavType.StringType; nullable = true; defaultValue = null },
+        )
+
+        fun build(filter: TaskFilter): String = when (filter) {
+            is TaskFilter.OfList -> "taskList?$ARG_LIST_ID=${filter.listId}"
+            is TaskFilter.Smart -> "taskList?$ARG_SMART=${filter.list.name}"
+        }
+
+        /** Reconstruct the filter from a destination's arguments. */
+        fun filterOf(smart: String?, listId: Long): TaskFilter =
+            if (smart != null) TaskFilter.Smart(SmartList.valueOf(smart))
+            else TaskFilter.OfList(listId)
+    }
+
+    /** A single task's detail. */
+    object TaskDetail {
+        const val ARG_TASK_ID = "taskId"
+        const val route = "taskDetail/{$ARG_TASK_ID}"
+        val arguments = listOf(navArgument(ARG_TASK_ID) { type = NavType.LongType })
+        fun build(taskId: Long): String = "taskDetail/$taskId"
+    }
+
+    /**
+     * The create / edit form. `taskId` set ([NO_ID] otherwise) ⇒ edit; for a new
+     * task, `presetListId` / `parentId` optionally seed the form.
+     */
+    object TaskEdit {
+        const val ARG_TASK_ID = "taskId"
+        const val ARG_PRESET_LIST_ID = "presetListId"
+        const val ARG_PARENT_ID = "parentId"
+        const val route =
+            "taskEdit?$ARG_TASK_ID={$ARG_TASK_ID}" +
+                "&$ARG_PRESET_LIST_ID={$ARG_PRESET_LIST_ID}" +
+                "&$ARG_PARENT_ID={$ARG_PARENT_ID}"
+
+        val arguments = listOf(
+            navArgument(ARG_TASK_ID) { type = NavType.LongType; defaultValue = NO_ID },
+            navArgument(ARG_PRESET_LIST_ID) { type = NavType.LongType; defaultValue = NO_ID },
+            navArgument(ARG_PARENT_ID) { type = NavType.LongType; defaultValue = NO_ID },
+        )
+
+        fun buildEdit(taskId: Long): String = "taskEdit?$ARG_TASK_ID=$taskId"
+
+        fun buildNew(presetListId: Long? = null, parentId: Long? = null): String {
+            val params = buildList {
+                if (presetListId != null) add("$ARG_PRESET_LIST_ID=$presetListId")
+                if (parentId != null) add("$ARG_PARENT_ID=$parentId")
+            }
+            return if (params.isEmpty()) "taskEdit" else "taskEdit?${params.joinToString("&")}"
+        }
+    }
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/navigation/FloretNavHost.kt

@@ -0,0 +1,119 @@
+package de.jeanlucmakiola.floret.ui.navigation
+
+import androidx.compose.animation.EnterTransition
+import androidx.compose.animation.ExitTransition
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.slideOutHorizontally
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.ui.Modifier
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.navigation.compose.NavHost
+import androidx.navigation.compose.composable
+import androidx.navigation.compose.rememberNavController
+import de.jeanlucmakiola.floret.domain.TaskFilter
+import de.jeanlucmakiola.floret.ui.detail.TaskDetailScreen
+import de.jeanlucmakiola.floret.ui.detail.TaskDetailViewModel
+import de.jeanlucmakiola.floret.ui.edit.TaskEditScreen
+import de.jeanlucmakiola.floret.ui.edit.TaskEditViewModel
+import de.jeanlucmakiola.floret.ui.lists.ListsScreen
+import de.jeanlucmakiola.floret.ui.tasklist.TaskListScreen
+import de.jeanlucmakiola.floret.ui.tasklist.TaskListViewModel
+
+/**
+ * The single in-app back stack: lists → task list → detail / edit.
+ *
+ * Each destination resolves its own Hilt [androidx.lifecycle.ViewModel] and
+ * feeds it the route arguments through that VM's `bind(...)` method (the VMs
+ * were built render-only in M1 and take their input this way rather than from a
+ * `SavedStateHandle`). Screens receive plain navigation lambdas so they stay
+ * unaware of the nav library.
+ */
+@Composable
+fun FloretNavHost(modifier: Modifier = Modifier) {
+    val nav = rememberNavController()
+    val slide = rememberNavSlideSpec()
+
+    NavHost(
+        navController = nav,
+        startDestination = Dest.LISTS,
+        modifier = modifier,
+        // Only the screen on top moves; the background is always held static.
+        // Forward is a plain fade-in over the held screen — calm, not a slide.
+        // Back (and the predictive-back drag, which drives popExit) is the snappy
+        // slide-out to the right, revealing the held screen unmoved.
+        enterTransition = { fadeIn() },
+        exitTransition = { ExitTransition.None },
+        popEnterTransition = { EnterTransition.None },
+        popExitTransition = { slideOutHorizontally(slide) { it } + fadeOut() },
+    ) {
+        composable(Dest.LISTS) {
+            ListsScreen(
+                onOpenFilter = { filter -> nav.navigate(Dest.TaskList.build(filter)) },
+                onNewTask = { nav.navigate(Dest.TaskEdit.buildNew()) },
+            )
+        }
+
+        composable(Dest.TaskList.route, arguments = Dest.TaskList.arguments) { entry ->
+            val args = entry.arguments
+            val filter = Dest.TaskList.filterOf(
+                smart = args?.getString(Dest.TaskList.ARG_SMART),
+                listId = args?.getLong(Dest.TaskList.ARG_LIST_ID) ?: Dest.NO_ID,
+            )
+            val vm: TaskListViewModel = hiltViewModel()
+            LaunchedEffect(filter) { vm.bind(filter) }
+
+            TaskListScreen(
+                filter = filter,
+                viewModel = vm,
+                onOpenTask = { taskId -> nav.navigate(Dest.TaskDetail.build(taskId)) },
+                onNewTask = {
+                    val presetListId = (filter as? TaskFilter.OfList)?.listId
+                    nav.navigate(Dest.TaskEdit.buildNew(presetListId = presetListId))
+                },
+                onBack = { nav.popBackStack() },
+            )
+        }
+
+        composable(Dest.TaskDetail.route, arguments = Dest.TaskDetail.arguments) { entry ->
+            val taskId = entry.arguments?.getLong(Dest.TaskDetail.ARG_TASK_ID) ?: Dest.NO_ID
+            val vm: TaskDetailViewModel = hiltViewModel()
+            LaunchedEffect(taskId) { vm.bind(taskId) }
+
+            TaskDetailScreen(
+                viewModel = vm,
+                onEdit = { nav.navigate(Dest.TaskEdit.buildEdit(taskId)) },
+                onDeleted = { nav.popBackStack() },
+                onBack = { nav.popBackStack() },
+                // A subtask opens its own detail — another entry on the stack, with
+                // its own VM bound to that id (it may have children of its own).
+                onOpenTask = { subtaskId -> nav.navigate(Dest.TaskDetail.build(subtaskId)) },
+            )
+        }
+
+        composable(Dest.TaskEdit.route, arguments = Dest.TaskEdit.arguments) { entry ->
+            val args = entry.arguments
+            val taskId = args?.getLong(Dest.TaskEdit.ARG_TASK_ID) ?: Dest.NO_ID
+            val presetListId = args?.getLong(Dest.TaskEdit.ARG_PRESET_LIST_ID) ?: Dest.NO_ID
+            val parentId = args?.getLong(Dest.TaskEdit.ARG_PARENT_ID) ?: Dest.NO_ID
+            val vm: TaskEditViewModel = hiltViewModel()
+            LaunchedEffect(taskId, presetListId, parentId) {
+                if (taskId != Dest.NO_ID) {
+                    vm.bindEdit(taskId)
+                } else {
+                    vm.bindNew(
+                        presetListId = presetListId.takeIf { it != Dest.NO_ID },
+                        parentId = parentId.takeIf { it != Dest.NO_ID },
+                    )
+                }
+            }
+
+            TaskEditScreen(
+                viewModel = vm,
+                onSaved = { nav.popBackStack() },
+                onBack = { nav.popBackStack() },
+            )
+        }
+    }
+}

app/src/main/java/de/jeanlucmakiola/floret/ui/navigation/FloretTransitions.kt

@@ -0,0 +1,21 @@
+package de.jeanlucmakiola.floret.ui.navigation
+
+import androidx.compose.animation.core.FiniteAnimationSpec
+import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.unit.IntOffset
+
+/**
+ * The horizontal slide spec for screen-to-screen navigation: the *fast*
+ * spring-physics spec from the active motion scheme — snappy with a subtle
+ * springy settle, rather than a fixed easing curve. Same choice as Calendula's
+ * calendar slide, so the two apps move the same way.
+ *
+ * Read in composable scope so the non-composable `NavHost` transition lambdas
+ * can capture it.
+ */
+@OptIn(ExperimentalMaterial3ExpressiveApi::class)
+@Composable
+fun rememberNavSlideSpec(): FiniteAnimationSpec<IntOffset> =
+    MaterialTheme.motionScheme.fastSpatialSpec()

app/src/main/java/de/jeanlucmakiola/floret/ui/tasklist/TaskListScreen.kt

@@ -0,0 +1,935 @@
+package de.jeanlucmakiola.floret.ui.tasklist
+
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.core.animateDpAsState
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.slideInVertically
+import androidx.compose.animation.slideOutVertically
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.background
+import androidx.compose.foundation.text.BasicTextField
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.interaction.collectIsPressedAsState
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.itemsIndexed
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.rounded.ArrowBack
+import androidx.compose.material.icons.automirrored.rounded.ListAlt
+import androidx.compose.material.icons.rounded.Add
+import androidx.compose.material.icons.rounded.Check
+import androidx.compose.material.icons.rounded.Checklist
+import androidx.compose.material.icons.rounded.Delete
+import androidx.compose.material.icons.rounded.ExpandMore
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.ExtendedFloatingActionButton
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.MediumTopAppBar
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Surface
+import androidx.compose.material3.SwipeToDismissBox
+import androidx.compose.material3.SwipeToDismissBoxValue
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.TextField
+import androidx.compose.material3.TextFieldDefaults
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.material3.rememberSwipeToDismissBoxState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import kotlinx.coroutines.delay
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.graphics.Shape
+import androidx.compose.ui.input.nestedscroll.nestedScroll
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.floret.R
+import de.jeanlucmakiola.floret.domain.DayWindow
+import de.jeanlucmakiola.floret.domain.Priority
+import de.jeanlucmakiola.floret.domain.SmartList
+import de.jeanlucmakiola.floret.domain.Task
+import de.jeanlucmakiola.floret.domain.TaskFilter
+import de.jeanlucmakiola.floret.domain.TaskSection
+import de.jeanlucmakiola.floret.domain.TaskSections
+import de.jeanlucmakiola.floret.ui.common.ListNameChip
+import de.jeanlucmakiola.floret.ui.common.Position
+import de.jeanlucmakiola.floret.ui.common.PriorityChip
+import de.jeanlucmakiola.floret.ui.common.formatDateTime
+import de.jeanlucmakiola.floret.ui.common.pastelize
+import de.jeanlucmakiola.floret.ui.common.positionOf
+import java.time.ZoneId
+import kotlin.time.Clock
+
+/**
+ * The tasks for one [TaskFilter]: due-date section headers, grouped tonal rows
+ * with a leading checkbox, swipe-to-complete (start→end) / swipe-to-delete
+ * (end→start), and — for a real list — an inline add field. Renders against the
+ * M1 [TaskListViewModel]; actions are fire-and-forget and flow back live.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun TaskListScreen(
+    filter: TaskFilter,
+    onOpenTask: (Long) -> Unit,
+    onNewTask: () -> Unit,
+    onBack: () -> Unit,
+    modifier: Modifier = Modifier,
+    viewModel: TaskListViewModel = hiltViewModel(),
+) {
+    val state by viewModel.state.collectAsStateWithLifecycle()
+    val scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior()
+    val listName = (state as? TaskListUiState.Content)?.listName
+
+    // Swipe-delete hides the row at once, then a floating "Deleted · Undo" chip
+    // gives an undo window: Undo restores it, otherwise the delete commits. A
+    // second delete while a chip is up commits the first (its window is over).
+    var undoTarget by remember { mutableStateOf<Task?>(null) }
+    val onRequestDelete: (Task) -> Unit = { task ->
+        undoTarget?.let { viewModel.commitDelete(it.taskId) }
+        viewModel.markPendingDelete(task)
+        undoTarget = task
+    }
+    LaunchedEffect(undoTarget) {
+        val target = undoTarget ?: return@LaunchedEffect
+        delay(4_000)
+        viewModel.commitDelete(target.taskId)
+        if (undoTarget?.taskId == target.taskId) undoTarget = null
+    }
+
+    Scaffold(
+        modifier = modifier.nestedScroll(scrollBehavior.nestedScrollConnection),
+        topBar = {
+            MediumTopAppBar(
+                title = { Text(titleFor(filter, listName)) },
+                navigationIcon = {
+                    IconButton(onClick = onBack) {
+                        Icon(
+                            Icons.AutoMirrored.Rounded.ArrowBack,
+                            contentDescription = stringResource(R.string.back),
+                        )
+                    }
+                },
+                scrollBehavior = scrollBehavior,
+            )
+        },
+        floatingActionButton = {
+            ExtendedFloatingActionButton(
+                onClick = onNewTask,
+                icon = { Icon(Icons.Rounded.Add, contentDescription = null) },
+                text = { Text(stringResource(R.string.new_task)) },
+            )
+        },
+    ) { inner ->
+        Box(modifier = Modifier.fillMaxSize()) {
+            when (val s = state) {
+                TaskListUiState.Loading -> Unit // brief; avoids a flash before first emission
+                TaskListUiState.Failure -> CenteredMessage(stringResource(R.string.task_list_failure), inner)
+                is TaskListUiState.Content -> TaskListBody(s, filter, inner, onOpenTask, onRequestDelete, viewModel)
+            }
+            UndoChip(
+                visible = undoTarget != null,
+                onUndo = {
+                    undoTarget?.let { viewModel.undoDelete(it.taskId) }
+                    undoTarget = null
+                },
+                modifier = Modifier
+                    .align(Alignment.BottomCenter)
+                    .padding(bottom = inner.calculateBottomPadding() + 24.dp),
+            )
+        }
+    }
+}
+
+/**
+ * A compact floating "snackchip" for an undoable delete — a rounded pill (not a
+ * full-width snackbar) sized to its content, sliding up from the bottom centre.
+ */
+@Composable
+private fun UndoChip(visible: Boolean, onUndo: () -> Unit, modifier: Modifier = Modifier) {
+    AnimatedVisibility(
+        visible = visible,
+        enter = slideInVertically { it } + fadeIn(),
+        exit = slideOutVertically { it } + fadeOut(),
+        modifier = modifier,
+    ) {
+        Surface(
+            color = MaterialTheme.colorScheme.surfaceContainerHighest,
+            contentColor = MaterialTheme.colorScheme.onSurface,
+            shape = RoundedCornerShape(50),
+            shadowElevation = 6.dp,
+        ) {
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                modifier = Modifier.padding(start = 20.dp, end = 8.dp, top = 6.dp, bottom = 6.dp),
+                horizontalArrangement = Arrangement.spacedBy(12.dp),
+            ) {
+                Text(
+                    text = stringResource(R.string.task_deleted),
+                    style = MaterialTheme.typography.bodyMedium,
+                )
+                TextButton(
+                    onClick = onUndo,
+                    contentPadding = PaddingValues(horizontal = 16.dp, vertical = 6.dp),
+                ) {
+                    Text(
+                        text = stringResource(R.string.undo),
+                        style = MaterialTheme.typography.labelLarge,
+                    )
+                }
+            }
+        }
+    }
+}
+
+@OptIn(ExperimentalMaterial3Api::class, ExperimentalFoundationApi::class)
+@Composable
+private fun TaskListBody(
+    state: TaskListUiState.Content,
+    filter: TaskFilter,
+    inner: PaddingValues,
+    onOpenTask: (Long) -> Unit,
+    onRequestDelete: (Task) -> Unit,
+    viewModel: TaskListViewModel,
+) {
+    val (todayStart, todayEnd) = remember { DayWindow.today(Clock.System.now(), ZoneId.systemDefault()) }
+    // A parent represents its children via a progress chip (counts come from the
+    // repository, over the full set), so drop children from the flat list — unless
+    // their parent isn't in this view (can happen in smart lists), where we keep
+    // them standalone so nothing silently vanishes.
+    val displayTasks = remember(state.tasks) {
+        val present = state.tasks.mapTo(HashSet()) { it.taskId }
+        state.tasks.filter { (it.parentId ?: 0L) <= 0L || it.parentId !in present }
+    }
+    val sections = remember(displayTasks) { TaskSections.of(displayTasks, todayStart, todayEnd) }
+    val showHeaders = sections.size > 1
+    val listId = (filter as? TaskFilter.OfList)?.listId
+    // In a mixed view (a smart list) the list colour bar + name disambiguate
+    // rows; inside a single real list both are redundant.
+    val showListName = filter is TaskFilter.Smart
+    // Completed tasks collapse away by default to keep the active list in focus.
+    var completedExpanded by rememberSaveable { mutableStateOf(false) }
+    // Parents the user expanded to reveal their subtasks inline. Children are
+    // grouped from the same flat task set the list already holds.
+    var expandedParents by rememberSaveable { mutableStateOf(emptySet<Long>()) }
+    val childrenByParent = remember(state.tasks) {
+        state.tasks.filter { it.isSubtask }.groupBy { it.parentId!! }
+    }
+
+    LazyColumn(
+        modifier = Modifier.fillMaxSize(),
+        contentPadding = PaddingValues(
+            top = inner.calculateTopPadding() + 8.dp,
+            bottom = inner.calculateBottomPadding() + 96.dp,
+        ),
+    ) {
+        if (listId != null) {
+            item(key = "inline-add") {
+                InlineAdd(onAdd = { title -> viewModel.quickAdd(title, listId) })
+            }
+        }
+
+        if (state.tasks.isEmpty()) {
+            item(key = "empty") { EmptyState(stringResource(R.string.task_list_empty)) }
+        }
+
+        sections.forEach { section ->
+            val collapsible = showHeaders && section.section == TaskSection.COMPLETED
+            if (showHeaders) {
+                stickyHeader(key = "hdr-${section.section}") {
+                    if (collapsible) {
+                        CollapsibleSectionHeader(
+                            label = sectionLabel(section.section),
+                            count = section.tasks.size,
+                            expanded = completedExpanded,
+                            onToggle = { completedExpanded = !completedExpanded },
+                        )
+                    } else {
+                        SectionHeader(sectionLabel(section.section))
+                    }
+                }
+            }
+            if (!collapsible || completedExpanded) {
+                // Flatten the section into one grouped run: each parent, followed
+                // by its subtasks when expanded. Each row's corners then come from
+                // its place in the whole run (positionOf below) — so the children
+                // read as a grouped list nested in the list's grouped list:
+                // full-width, connecting to the parent above (small top corners),
+                // and the run rounds off (full corners) only at its genuine ends.
+                val rows = buildList {
+                    val topLevel = section.tasks
+                    topLevel.forEachIndexed { p, task ->
+                        val children = childrenByParent[task.taskId].orEmpty()
+                        // Only expandable when we hold every child: true in a real
+                        // list, but a smart list may omit children due on other
+                        // days, and a half-shown set would mislead.
+                        val canExpand = task.subtaskTotal > 0 && children.size == task.subtaskTotal
+                        val isExpanded = canExpand && task.taskId in expandedParents
+                        // Top-level tasks keep their own connected run — full top
+                        // only on the first, full bottom only on the last — so the
+                        // task after an expanded one stays mid-run (small top). An
+                        // expanded parent's bottom opens (small) to meet its subtasks.
+                        val parentPosition = cornerPosition(
+                            topFull = p == 0,
+                            bottomFull = if (isExpanded) false else p == topLevel.lastIndex,
+                        )
+                        add(RenderRow(ListRow.Parent(task, canExpand, isExpanded), parentPosition))
+                        if (isExpanded) {
+                            // Subtasks connect up to the parent (small top) and to
+                            // each other; the inline add row below closes the group,
+                            // so every subtask is mid-run (small top + bottom).
+                            children.sortedBy { it.isCompleted }.forEach { sub ->
+                                add(RenderRow(ListRow.Sub(sub), cornerPosition(topFull = false, bottomFull = false)))
+                            }
+                            // The add row rounds the group off (full bottom),
+                            // independent of whatever top-level task follows.
+                            add(RenderRow(ListRow.AddSub(task), cornerPosition(topFull = false, bottomFull = true)))
+                        }
+                    }
+                }
+                itemsIndexed(rows, key = { _, r -> r.row.key }) { index, r ->
+                    val lastInRun = index == rows.lastIndex
+                    when (val row = r.row) {
+                        is ListRow.Parent -> TaskRow(
+                            task = row.task,
+                            position = r.position,
+                            lastInRun = lastInRun,
+                            showListName = showListName,
+                            subtaskDone = row.task.subtaskDone,
+                            subtaskTotal = row.task.subtaskTotal,
+                            expanded = row.expanded,
+                            onToggleExpand = if (row.expandable) {
+                                {
+                                    expandedParents = if (row.task.taskId in expandedParents) {
+                                        expandedParents - row.task.taskId
+                                    } else {
+                                        expandedParents + row.task.taskId
+                                    }
+                                }
+                            } else {
+                                null
+                            },
+                            onToggle = { viewModel.toggleComplete(row.task) },
+                            onDelete = { onRequestDelete(row.task) },
+                            onClick = { onOpenTask(row.task.taskId) },
+                        )
+                        is ListRow.Sub -> SubtaskRow(
+                            task = row.task,
+                            position = r.position,
+                            lastInRun = lastInRun,
+                            onToggle = { viewModel.toggleComplete(row.task) },
+                            onClick = { onOpenTask(row.task.taskId) },
+                        )
+                        is ListRow.AddSub -> AddSubtaskRow(
+                            position = r.position,
+                            lastInRun = lastInRun,
+                            onAdd = { viewModel.quickAddSubtask(row.parent, it) },
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+/** Inline "add a task" — title only, into the current list. */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun InlineAdd(onAdd: (String) -> Unit) {
+    var text by remember { mutableStateOf("") }
+    fun submit() {
+        if (text.isNotBlank()) {
+            onAdd(text.trim())
+            text = ""
+        }
+    }
+    Surface(
+        shape = RoundedCornerShape(22.dp),
+        color = MaterialTheme.colorScheme.surfaceContainerHigh,
+        modifier = Modifier.fillMaxWidth().padding(horizontal = 16.dp, vertical = 4.dp),
+    ) {
+        TextField(
+            value = text,
+            onValueChange = { text = it },
+            placeholder = { Text(stringResource(R.string.add_task_hint)) },
+            leadingIcon = { Icon(Icons.Rounded.Add, contentDescription = null) },
+            trailingIcon = {
+                if (text.isNotBlank()) {
+                    IconButton(onClick = ::submit) {
+                        Icon(Icons.Rounded.Check, contentDescription = stringResource(R.string.cd_add_task))
+                    }
+                }
+            },
+            singleLine = true,
+            keyboardOptions = androidx.compose.foundation.text.KeyboardOptions(imeAction = ImeAction.Done),
+            keyboardActions = androidx.compose.foundation.text.KeyboardActions(onDone = { submit() }),
+            colors = TextFieldDefaults.colors(
+                focusedContainerColor = Color.Transparent,
+                unfocusedContainerColor = Color.Transparent,
+                focusedIndicatorColor = Color.Transparent,
+                unfocusedIndicatorColor = Color.Transparent,
+            ),
+            modifier = Modifier.fillMaxWidth(),
+        )
+    }
+}
+
+/**
+ * One task row: a tonal grouped-card surface (corners from [position], morphing
+ * rounder on press — the app's shape family) wrapped in a swipe box. Swiping
+ * right toggles complete (snaps back); swiping left deletes.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun TaskRow(
+    task: Task,
+    position: Position,
+    lastInRun: Boolean,
+    showListName: Boolean,
+    subtaskDone: Int,
+    subtaskTotal: Int,
+    expanded: Boolean,
+    onToggleExpand: (() -> Unit)?,
+    onToggle: () -> Unit,
+    onDelete: () -> Unit,
+    onClick: () -> Unit,
+) {
+    val dismissState = rememberSwipeToDismissBoxState(
+        confirmValueChange = { value ->
+            when (value) {
+                // Both snap back: complete toggles status; delete hands off to the
+                // undo flow, which removes the row from the data. Never *confirm*
+                // the dismiss — a terminal dismissed state strands a stale
+                // background bar and won't re-arm when the row is restored.
+                SwipeToDismissBoxValue.StartToEnd -> { onToggle(); false }
+                SwipeToDismissBoxValue.EndToStart -> { onDelete(); false }
+                SwipeToDismissBoxValue.Settled -> false
+            }
+        },
+    )
+    // A small gap below every row but the run's last — including a group-ending
+    // Bottom that's followed by a fresh card, so the two groups read apart.
+    val gap = if (lastInRun) Modifier else Modifier.padding(bottom = 2.dp)
+
+    SwipeToDismissBox(
+        state = dismissState,
+        modifier = Modifier.fillMaxWidth().padding(horizontal = 16.dp).then(gap),
+        // dismissDirection (not targetValue) tracks the live drag, so the colour +
+        // icon reveal as you swipe rather than only once the threshold is crossed.
+        backgroundContent = { SwipeBackground(dismissState.dismissDirection, task.isCompleted) },
+    ) {
+        TaskRowContent(task, position, showListName, subtaskDone, subtaskTotal, expanded, onToggleExpand, onToggle, onClick)
+    }
+}
+
+@OptIn(ExperimentalMaterial3Api::class, ExperimentalLayoutApi::class)
+@Composable
+private fun TaskRowContent(
+    task: Task,
+    position: Position,
+    showListName: Boolean,
+    subtaskDone: Int,
+    subtaskTotal: Int,
+    expanded: Boolean,
+    onToggleExpand: (() -> Unit)?,
+    onToggle: () -> Unit,
+    onClick: () -> Unit,
+) {
+    val interaction = remember { MutableInteractionSource() }
+    val pressed by interaction.collectIsPressedAsState()
+    val full by animateDpAsState(if (pressed) 36.dp else 22.dp, label = "fullCorner")
+    val small by animateDpAsState(if (pressed) 36.dp else 6.dp, label = "smallCorner")
+    val dark = isSystemInDarkTheme()
+    val due = task.due?.formatDateTime(task.isAllDay)
+    val listName = task.listName?.takeIf { showListName && it.isNotBlank() }
+    val hasSupporting = due != null || listName != null || subtaskTotal > 0 ||
+        task.priority != Priority.NONE
+
+    Surface(
+        onClick = onClick,
+        shape = cardShape(position, full, small),
+        color = MaterialTheme.colorScheme.surfaceContainerHigh,
+        interactionSource = interaction,
+        modifier = Modifier.fillMaxWidth(),
+    ) {
+        // Hand-laid row (not ListItem) so a one- vs two-line body never trips
+        // ListItem's three-line heuristic and leaves dead space at the bottom.
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .heightIn(min = 64.dp)
+                .padding(start = 12.dp, end = 16.dp, top = 8.dp, bottom = 8.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            // Calendula's signature accent: a slim pastelised colour bar for the
+            // list, paired here with the task's completion checkbox.
+            Box(
+                modifier = Modifier
+                    .size(width = 5.dp, height = 32.dp)
+                    .clip(RoundedCornerShape(3.dp))
+                    .background(pastelize(task.effectiveColor, dark)),
+            )
+            Checkbox(checked = task.isCompleted, onCheckedChange = { onToggle() })
+            Spacer(Modifier.width(4.dp))
+            Column(modifier = Modifier.weight(1f)) {
+                Text(
+                    text = task.title.ifBlank { stringResource(R.string.task_untitled) },
+                    style = MaterialTheme.typography.bodyLarge,
+                    maxLines = 2,
+                    overflow = TextOverflow.Ellipsis,
+                    textDecoration = if (task.isCompleted) TextDecoration.LineThrough else null,
+                    color = if (task.isCompleted) {
+                        MaterialTheme.colorScheme.onSurfaceVariant
+                    } else {
+                        MaterialTheme.colorScheme.onSurface
+                    },
+                )
+                if (hasSupporting) {
+                    Spacer(Modifier.height(3.dp))
+                    // Flow so the chips wrap to a further line when due date + list
+                    // + subtask progress can't share one (e.g. a dated task with
+                    // subtasks), rather than squeezing the trailing chip.
+                    FlowRow(
+                        verticalArrangement = Arrangement.spacedBy(3.dp),
+                        horizontalArrangement = Arrangement.spacedBy(8.dp),
+                        itemVerticalAlignment = Alignment.CenterVertically,
+                    ) {
+                        if (task.priority != Priority.NONE) {
+                            PriorityChip(task.priority, priorityLabel(task.priority))
+                        }
+                        if (due != null) {
+                            Text(
+                                text = due,
+                                style = MaterialTheme.typography.bodyMedium,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            )
+                        }
+                        if (listName != null) ListNameChip(listName, task.effectiveColor)
+                        if (subtaskTotal > 0) SubtaskCountChip(subtaskDone, subtaskTotal)
+                    }
+                }
+            }
+            // Trailing area is only ever the expand control, so the row's right
+            // edge stays put whether or not the task has children (priority now
+            // rides in the supporting chip row instead of a shifting trailing flag).
+            if (onToggleExpand != null) {
+                SubtaskExpandButton(expanded = expanded, onToggle = onToggleExpand)
+            }
+        }
+    }
+}
+
+/** A small neutral pill showing subtask progress, e.g. "3 / 5". */
+@Composable
+private fun SubtaskCountChip(done: Int, total: Int) {
+    Surface(
+        color = MaterialTheme.colorScheme.surfaceContainerHighest,
+        shape = RoundedCornerShape(50),
+    ) {
+        Row(
+            modifier = Modifier.padding(horizontal = 8.dp, vertical = 2.dp),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.spacedBy(4.dp),
+        ) {
+            Icon(
+                imageVector = Icons.AutoMirrored.Rounded.ListAlt,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.size(14.dp),
+            )
+            Text(
+                text = "$done / $total",
+                style = MaterialTheme.typography.labelSmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+        }
+    }
+}
+
+/**
+ * The inline "add a subtask" row that closes an expanded group — a [BasicTextField]
+ * aligned with the subtask titles (leading + where the checkbox sits), submitting
+ * on the tick or the IME action. Same grouped-card segment as the rows around it.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun AddSubtaskRow(
+    position: Position,
+    lastInRun: Boolean,
+    onAdd: (String) -> Unit,
+) {
+    var text by remember { mutableStateOf("") }
+    fun submit() {
+        if (text.isNotBlank()) {
+            onAdd(text.trim())
+            text = ""
+        }
+    }
+    val gap = if (lastInRun) Modifier else Modifier.padding(bottom = 2.dp)
+    Surface(
+        shape = cardShape(position, 22.dp, 6.dp),
+        // Same tone as the subtask rows it closes, so the group reads as one unit.
+        color = MaterialTheme.colorScheme.surfaceContainer,
+        modifier = Modifier.fillMaxWidth().padding(horizontal = 16.dp).then(gap),
+    ) {
+        Row(
+            modifier = Modifier.fillMaxWidth().heightIn(min = 52.dp).padding(start = 12.dp, end = 8.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Spacer(Modifier.width(5.dp)) // the parents' colour-bar slot, kept for alignment
+            Box(modifier = Modifier.size(48.dp), contentAlignment = Alignment.Center) {
+                Icon(
+                    imageVector = Icons.Rounded.Add,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+            Spacer(Modifier.width(4.dp))
+            BasicTextField(
+                value = text,
+                onValueChange = { text = it },
+                singleLine = true,
+                textStyle = MaterialTheme.typography.bodyLarge.copy(color = MaterialTheme.colorScheme.onSurface),
+                cursorBrush = SolidColor(MaterialTheme.colorScheme.primary),
+                keyboardOptions = androidx.compose.foundation.text.KeyboardOptions(imeAction = ImeAction.Done),
+                keyboardActions = androidx.compose.foundation.text.KeyboardActions(onDone = { submit() }),
+                modifier = Modifier.weight(1f),
+                decorationBox = { inner ->
+                    if (text.isEmpty()) {
+                        Text(
+                            text = stringResource(R.string.add_subtask_hint),
+                            style = MaterialTheme.typography.bodyLarge,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        )
+                    }
+                    inner()
+                },
+            )
+            if (text.isNotBlank()) {
+                IconButton(onClick = ::submit) {
+                    Icon(
+                        Icons.Rounded.Check,
+                        contentDescription = stringResource(R.string.cd_add_task),
+                        tint = MaterialTheme.colorScheme.primary,
+                    )
+                }
+            }
+        }
+    }
+}
+
+/** The trailing expand/collapse control for a parent row — a rotating chevron. */
+@Composable
+private fun SubtaskExpandButton(expanded: Boolean, onToggle: () -> Unit) {
+    val rotation by animateFloatAsState(if (expanded) 180f else 0f, label = "subtaskExpand")
+    IconButton(onClick = onToggle) {
+        Icon(
+            imageVector = Icons.Rounded.ExpandMore,
+            contentDescription = stringResource(
+                if (expanded) R.string.cd_collapse_subtasks else R.string.cd_expand_subtasks,
+            ),
+            tint = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.rotate(rotation),
+        )
+    }
+}
+
+/** A visual row in a flattened section run: a top-level task, or one of its subtasks. */
+private sealed interface ListRow {
+    val key: Long
+
+    data class Parent(val task: Task, val expandable: Boolean, val expanded: Boolean) : ListRow {
+        override val key: Long get() = task.taskId
+    }
+
+    data class Sub(val task: Task) : ListRow {
+        override val key: Long get() = task.taskId
+    }
+
+    /** The inline "add a subtask" row that closes an expanded group. */
+    data class AddSub(val parent: Task) : ListRow {
+        // Negative so it never collides with a real (positive) provider task id.
+        override val key: Long get() = -parent.taskId
+    }
+}
+
+/** A flattened row paired with the grouped-card corners it should render with. */
+private data class RenderRow(val row: ListRow, val position: Position)
+
+/**
+ * Map independent top/bottom corner choices to a [Position]. `full` = the big
+ * outer corner radius (a run's start/end); otherwise the small connecting radius.
+ * Letting each edge be chosen on its own lets a subtask group round off (full
+ * bottom) while the next top-level task keeps a small top and stays mid-run.
+ */
+private fun cornerPosition(topFull: Boolean, bottomFull: Boolean): Position = when {
+    topFull && bottomFull -> Position.Alone
+    topFull -> Position.Top
+    bottomFull -> Position.Bottom
+    else -> Position.Middle
+}
+
+/**
+ * One subtask row inside an expanded parent: a full-width grouped-card segment
+ * (same tonal surface, corners-from-[position], press-morph as the task rows), so
+ * it's part of the same grouped run. The only difference is a leading indent
+ * before the checkbox to convey nesting — the card width is preserved.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun SubtaskRow(
+    task: Task,
+    position: Position,
+    lastInRun: Boolean,
+    onToggle: () -> Unit,
+    onClick: () -> Unit,
+) {
+    val interaction = remember { MutableInteractionSource() }
+    val pressed by interaction.collectIsPressedAsState()
+    val full by animateDpAsState(if (pressed) 36.dp else 22.dp, label = "subFullCorner")
+    val small by animateDpAsState(if (pressed) 36.dp else 6.dp, label = "subSmallCorner")
+    val gap = if (lastInRun) Modifier else Modifier.padding(bottom = 2.dp)
+    Surface(
+        onClick = onClick,
+        shape = cardShape(position, full, small),
+        // A step below the parents' surfaceContainerHigh so the subtask group
+        // reads as a distinct, recessive tone — the nesting cue alongside shape.
+        color = MaterialTheme.colorScheme.surfaceContainer,
+        interactionSource = interaction,
+        modifier = Modifier.fillMaxWidth().padding(horizontal = 16.dp).then(gap),
+    ) {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .heightIn(min = 56.dp)
+                .padding(start = 12.dp, end = 16.dp, top = 6.dp, bottom = 6.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            // No colour bar — that absence (with the grouped nesting) marks the row
+            // as a subtask. Reserve the bar's 5dp so the checkbox still lines up
+            // with the parent rows' checkboxes rather than indenting.
+            Spacer(Modifier.width(5.dp))
+            Checkbox(checked = task.isCompleted, onCheckedChange = { onToggle() })
+            Spacer(Modifier.width(4.dp))
+            Text(
+                text = task.title.ifBlank { stringResource(R.string.task_untitled) },
+                style = MaterialTheme.typography.bodyLarge,
+                maxLines = 2,
+                overflow = TextOverflow.Ellipsis,
+                textDecoration = if (task.isCompleted) TextDecoration.LineThrough else null,
+                color = if (task.isCompleted) {
+                    MaterialTheme.colorScheme.onSurfaceVariant
+                } else {
+                    MaterialTheme.colorScheme.onSurface
+                },
+                modifier = Modifier.weight(1f),
+            )
+        }
+    }
+}
+
+/** The colored reveal behind a swiping row: complete on the left, delete on the right. */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun SwipeBackground(target: SwipeToDismissBoxValue, isCompleted: Boolean) {
+    val (color, icon, desc, alignment) = when (target) {
+        SwipeToDismissBoxValue.StartToEnd -> SwipeStyle(
+            MaterialTheme.colorScheme.primaryContainer,
+            Icons.Rounded.Check,
+            if (isCompleted) R.string.cd_reopen else R.string.cd_complete,
+            Alignment.CenterStart,
+        )
+        SwipeToDismissBoxValue.EndToStart -> SwipeStyle(
+            MaterialTheme.colorScheme.errorContainer,
+            Icons.Rounded.Delete,
+            R.string.delete,
+            Alignment.CenterEnd,
+        )
+        SwipeToDismissBoxValue.Settled -> SwipeStyle(
+            Color.Transparent, Icons.Rounded.Check, R.string.cd_complete, Alignment.CenterStart,
+        )
+    }
+    Surface(color = color, shape = RoundedCornerShape(22.dp), modifier = Modifier.fillMaxSize()) {
+        Box(modifier = Modifier.fillMaxSize().padding(horizontal = 24.dp), contentAlignment = alignment) {
+            Icon(icon, contentDescription = stringResource(desc))
+        }
+    }
+}
+
+private data class SwipeStyle(
+    val color: Color,
+    val icon: androidx.compose.ui.graphics.vector.ImageVector,
+    val descRes: Int,
+    val alignment: Alignment,
+)
+
+private fun cardShape(position: Position, full: androidx.compose.ui.unit.Dp, small: androidx.compose.ui.unit.Dp): Shape =
+    when (position) {
+        Position.Alone -> RoundedCornerShape(full)
+        Position.Top -> RoundedCornerShape(topStart = full, topEnd = full, bottomStart = small, bottomEnd = small)
+        Position.Middle -> RoundedCornerShape(small)
+        Position.Bottom -> RoundedCornerShape(topStart = small, topEnd = small, bottomStart = full, bottomEnd = full)
+    }
+
+@Composable
+private fun SectionHeader(text: String) {
+    // Opaque surface so rows scroll cleanly under the pinned header.
+    Surface(color = MaterialTheme.colorScheme.surface, modifier = Modifier.fillMaxWidth()) {
+        Text(
+            text = text,
+            style = MaterialTheme.typography.titleSmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.padding(start = 28.dp, end = 28.dp, top = 16.dp, bottom = 8.dp),
+        )
+    }
+}
+
+/** A tappable section header with a count and a chevron that rotates on expand. */
+@Composable
+private fun CollapsibleSectionHeader(
+    label: String,
+    count: Int,
+    expanded: Boolean,
+    onToggle: () -> Unit,
+) {
+    val rotation by animateFloatAsState(if (expanded) 180f else 0f, label = "chevron")
+    Surface(
+        onClick = onToggle,
+        color = MaterialTheme.colorScheme.surface,
+        modifier = Modifier.fillMaxWidth(),
+    ) {
+        Row(
+            modifier = Modifier.padding(start = 28.dp, end = 20.dp, top = 16.dp, bottom = 8.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Text(
+                text = label,
+                style = MaterialTheme.typography.titleSmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            Spacer(Modifier.size(8.dp))
+            Text(
+                text = count.toString(),
+                style = MaterialTheme.typography.labelLarge,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.weight(1f),
+            )
+            Icon(
+                imageVector = Icons.Rounded.ExpandMore,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.rotate(rotation),
+            )
+        }
+    }
+}
+
+/** Icon + message for an empty list — the Calendula agenda-empty pattern. */
+@Composable
+private fun EmptyState(text: String) {
+    Column(
+        modifier = Modifier.fillMaxWidth().padding(horizontal = 32.dp, vertical = 64.dp),
+        horizontalAlignment = Alignment.CenterHorizontally,
+    ) {
+        Icon(
+            imageVector = Icons.Rounded.Checklist,
+            contentDescription = null,
+            tint = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.size(48.dp),
+        )
+        Spacer(Modifier.height(16.dp))
+        Text(
+            text = text,
+            style = MaterialTheme.typography.titleMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center,
+        )
+    }
+}
+
+@Composable
+private fun CenteredMessage(text: String, inner: PaddingValues) {
+    Box(
+        modifier = Modifier.fillMaxSize().padding(inner).padding(32.dp),
+        contentAlignment = Alignment.Center,
+    ) {
+        Text(
+            text = text,
+            style = MaterialTheme.typography.bodyLarge,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center,
+        )
+    }
+}
+
+@Composable
+private fun titleFor(filter: TaskFilter, listName: String?): String = when (filter) {
+    is TaskFilter.OfList -> listName ?: stringResource(R.string.tasks_title)
+    is TaskFilter.Smart -> stringResource(
+        when (filter.list) {
+            SmartList.TODAY -> R.string.smart_today
+            SmartList.UPCOMING -> R.string.smart_upcoming
+            SmartList.OVERDUE -> R.string.smart_overdue
+            SmartList.ALL -> R.string.smart_all
+            SmartList.NO_DATE -> R.string.smart_no_date
+            SmartList.COMPLETED -> R.string.smart_completed
+        },
+    )
+}
+
+@Composable
+private fun sectionLabel(section: TaskSection): String = stringResource(
+    when (section) {
+        TaskSection.OVERDUE -> R.string.section_overdue
+        TaskSection.TODAY -> R.string.section_today
+        TaskSection.UPCOMING -> R.string.section_upcoming
+        TaskSection.NO_DATE -> R.string.section_no_date
+        TaskSection.COMPLETED -> R.string.section_completed
+    },
+)
+
+@Composable
+internal fun priorityLabel(priority: Priority): String = stringResource(
+    when (priority) {
+        Priority.NONE -> R.string.priority_none
+        Priority.LOW -> R.string.priority_low
+        Priority.MEDIUM -> R.string.priority_medium
+        Priority.HIGH -> R.string.priority_high
+    },
+)

app/src/main/java/de/jeanlucmakiola/floret/ui/tasklist/TaskListViewModel.kt

@@ -12,6 +12,7 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.map
@@ -23,7 +24,13 @@ import javax.inject.Inject
 sealed interface TaskListUiState {
     data object Loading : TaskListUiState
     data object Failure : TaskListUiState
-    data class Content(val tasks: List<Task>) : TaskListUiState
+
+    /**
+     * [listName] is the real list's name when the filter is a
+     * [TaskFilter.OfList] (for the top-bar title), `null` for smart lists —
+     * the screen falls back to the smart label in that case.
+     */
+    data class Content(val tasks: List<Task>, val listName: String? = null) : TaskListUiState
 }
 
 /**
@@ -39,11 +46,30 @@ class TaskListViewModel @Inject constructor(
 
     private val filter = MutableStateFlow<TaskFilter?>(null)
 
+    /** Tasks swiped to delete but not yet committed — hidden until the undo lapses. */
+    private val pendingDeletes = MutableStateFlow<Set<Long>>(emptySet())
+
     val state: StateFlow<TaskListUiState> =
         filter.filterNotNull()
             .flatMapLatest { f ->
-                repository.tasks(f)
+                val tasks = repository.tasks(f)
-                    .map<List<Task>, TaskListUiState> { TaskListUiState.Content(it) }
+                val content: kotlinx.coroutines.flow.Flow<TaskListUiState> = when (f) {
+                    is TaskFilter.OfList ->
+                        combine(tasks, repository.taskLists()) { list, lists ->
+                            TaskListUiState.Content(list, lists.firstOrNull { it.id == f.listId }?.name)
+                        }
+                    is TaskFilter.Smart ->
+                        tasks.map { TaskListUiState.Content(it) }
+                }
+                // Drop rows pending an undoable delete so the row vanishes on swipe
+                // while the actual provider delete waits for the snackbar to commit.
+                combine(content, pendingDeletes) { st, pending ->
+                    if (st is TaskListUiState.Content) {
+                        st.copy(tasks = st.tasks.filter { it.taskId !in pending })
+                    } else {
+                        st
+                    }
+                }
                     .onStart { emit(TaskListUiState.Loading) }
                     .catch { emit(TaskListUiState.Failure) }
             }
@@ -55,8 +81,24 @@ class TaskListViewModel @Inject constructor(
         runCatching { repository.setCompleted(task.taskId, !task.isCompleted) }
     }
 
-    fun delete(task: Task) = viewModelScope.launch {
+    /** Swipe-delete: hide the row now; the screen's snackbar commits or restores it. */
-        runCatching { repository.deleteTask(task.taskId) }
+    fun markPendingDelete(task: Task) {
+        pendingDeletes.value = pendingDeletes.value + task.taskId
+    }
+
+    /** Undo — stop hiding the task; it returns to the list. */
+    fun undoDelete(taskId: Long) {
+        pendingDeletes.value = pendingDeletes.value - taskId
+    }
+
+    /**
+     * Commit the delete once the undo window passes. The id stays in the pending
+     * set: the task is gone from the provider so it can't reappear, and removing
+     * it could briefly un-hide the row before the provider change propagates.
+     */
+    fun commitDelete(taskId: Long) = viewModelScope.launch {
+        if (taskId !in pendingDeletes.value) return@launch
+        runCatching { repository.deleteTask(taskId) }
     }
 
     /** Inline "add task" — title only, into [listId]. */
@@ -64,4 +106,14 @@ class TaskListViewModel @Inject constructor(
         if (title.isBlank() || listId <= 0L) return@launch
         runCatching { repository.createTask(TaskForm(title = title, listId = listId)) }
     }
+
+    /** Inline "add subtask" from an expanded list group — files it under [parent]. */
+    fun quickAddSubtask(parent: Task, title: String) = viewModelScope.launch {
+        if (title.isBlank() || parent.listId <= 0L) return@launch
+        runCatching {
+            repository.createTask(
+                TaskForm(title = title.trim(), listId = parent.listId, parentId = parent.taskId),
+            )
+        }
+    }
 }

app/src/main/res/values/strings.xml

@@ -4,6 +4,105 @@
 
     <!-- Generic -->
     <string name="task_untitled">Untitled task</string>
+    <string name="back">Back</string>
+    <string name="save">Save</string>
+    <string name="delete">Delete</string>
+
+    <!-- Task list -->
+    <string name="tasks_title">Tasks</string>
+    <string name="task_list_empty">No tasks here yet.</string>
+    <string name="task_list_failure">Could not load these tasks.</string>
+    <string name="smart_no_date">No date</string>
+    <string name="smart_completed">Completed</string>
+
+    <!-- Task detail -->
+    <string name="task_detail_title">Task</string>
+    <string name="task_detail_not_found">This task no longer exists.</string>
+    <string name="edit">Edit</string>
+
+    <!-- Task edit -->
+    <string name="edit_task_title">Edit task</string>
+    <string name="new_task_title">New task</string>
+    <string name="field_title">Title</string>
+    <string name="field_description">Description</string>
+    <string name="edit_save_failed">Could not save. Try again.</string>
+
+    <!-- Task list: inline add + swipe -->
+    <string name="add_task_hint">Add a task</string>
+    <string name="add_subtask_hint">Add a subtask</string>
+    <string name="cd_add_task">Add task</string>
+    <string name="cd_complete">Complete</string>
+    <string name="cd_reopen">Reopen</string>
+    <string name="task_deleted">Deleted</string>
+    <string name="undo">Undo</string>
+    <string name="cd_expand_subtasks">Show subtasks</string>
+    <string name="cd_collapse_subtasks">Hide subtasks</string>
+
+    <!-- Sections (due-date buckets) -->
+    <string name="section_overdue">Overdue</string>
+    <string name="section_today">Today</string>
+    <string name="section_upcoming">Upcoming</string>
+    <string name="section_no_date">No date</string>
+    <string name="section_completed">Completed</string>
+
+    <!-- Priority -->
+    <string name="priority_none">None</string>
+    <string name="priority_low">Low</string>
+    <string name="priority_medium">Medium</string>
+    <string name="priority_high">High</string>
+
+    <!-- Task detail -->
+    <string name="detail_mark_complete">Mark complete</string>
+    <string name="detail_mark_incomplete">Mark not complete</string>
+    <string name="detail_list">List</string>
+    <string name="detail_due">Due</string>
+    <string name="detail_start">Starts</string>
+    <string name="detail_priority">Priority</string>
+    <string name="detail_progress">Progress</string>
+    <string name="detail_subtasks">Subtasks</string>
+    <string name="detail_parent">Parent task</string>
+    <string name="detail_part_of">Part of</string>
+    <string name="percent_complete">%1$d%%</string>
+
+    <!-- Task edit -->
+    <string name="edit_list_label">List</string>
+    <string name="edit_start_label">Starts</string>
+    <string name="edit_due_label">Due</string>
+    <string name="edit_all_day">All day</string>
+    <string name="edit_priority_label">Priority</string>
+    <string name="edit_progress_label">Progress</string>
+    <string name="edit_parent_label">Parent task</string>
+    <string name="edit_parent_none">None (top-level)</string>
+    <string name="edit_parent_search">Search tasks</string>
+    <string name="edit_parent_empty">No matching tasks in this list.</string>
+    <string name="edit_reminder_label">Reminder</string>
+    <string name="edit_set">Set</string>
+    <string name="edit_clear">Clear</string>
+    <string name="edit_title_hint">Task title</string>
+    <string name="edit_when">When</string>
+    <string name="edit_more_fields">More fields</string>
+    <string name="close">Close</string>
+    <string name="dialog_cancel">Cancel</string>
+
+    <!-- Save conflict -->
+    <string name="edit_conflict_title">Task changed elsewhere</string>
+    <string name="edit_conflict_body">This task was updated somewhere else (a sync or another app) since you opened it. Overwrite those changes with your edits?</string>
+    <string name="edit_conflict_overwrite">Overwrite</string>
+
+    <!-- Reminder offsets -->
+    <string name="reminder_none">None</string>
+    <string name="reminder_at_due">At time of task</string>
+    <string name="reminder_5_min">5 minutes before</string>
+    <string name="reminder_10_min">10 minutes before</string>
+    <string name="reminder_30_min">30 minutes before</string>
+    <string name="reminder_1_hour">1 hour before</string>
+    <string name="reminder_1_day">1 day before</string>
+
+    <!-- Form validation -->
+    <string name="error_blank_title">Enter a title.</string>
+    <string name="error_no_list">Choose a list.</string>
+    <string name="error_due_before_start">Due can\'t be before the start.</string>
+    <string name="error_reminder_without_due">Set a due date to use a reminder.</string>
 
     <!-- Lists overview -->
     <string name="lists_header">Lists</string>

app/src/test/java/de/jeanlucmakiola/floret/data/tasks/TaskWriteMapperTest.kt

@@ -28,6 +28,50 @@ class TaskWriteMapperTest {
         assertThat(values[Tasks.TZ]).isEqualTo("Europe/Berlin")
     }
 
+    @Test
+    fun `percent complete is written and clamped to 0-100`() {
+        val values = TaskWriteMapper.taskValues(
+            TaskForm(title = "x", listId = 1L, percentComplete = 140),
+            tzId = "UTC",
+        )
+        assertThat(values[Tasks.PERCENT_COMPLETE]).isEqualTo(100)
+
+        val unset = TaskWriteMapper.taskValues(TaskForm(title = "x", listId = 1L), tzId = "UTC")
+        assertThat(unset[Tasks.PERCENT_COMPLETE]).isNull()
+    }
+
+    @Test
+    fun `progress keeps completion in sync both ways`() {
+        // 100% completes the task (timestamp left to the provider / existing value).
+        val done = TaskWriteMapper.taskValues(
+            TaskForm(title = "x", listId = 1L, percentComplete = 100),
+            tzId = "UTC",
+        )
+        assertThat(done[Tasks.STATUS]).isEqualTo(TasksContract.STATUS_COMPLETED)
+        assertThat(done.containsKey(Tasks.COMPLETED)).isFalse()
+
+        // Below 100% reopens it and clears the completion timestamp.
+        val reopened = TaskWriteMapper.taskValues(
+            TaskForm(title = "x", listId = 1L, percentComplete = 75),
+            tzId = "UTC",
+        )
+        assertThat(reopened[Tasks.STATUS]).isEqualTo(TasksContract.STATUS_IN_PROCESS)
+        assertThat(reopened[Tasks.COMPLETED]).isNull()
+
+        // No percent in the form ⇒ status is left to the complete toggle.
+        val untouched = TaskWriteMapper.taskValues(TaskForm(title = "x", listId = 1L), tzId = "UTC")
+        assertThat(untouched.containsKey(Tasks.STATUS)).isFalse()
+    }
+
+    @Test
+    fun `parent id is written so a task can be filed under another`() {
+        val values = TaskWriteMapper.taskValues(
+            TaskForm(title = "x", listId = 1L, parentId = 7L),
+            tzId = "UTC",
+        )
+        assertThat(values[Tasks.PARENT_ID]).isEqualTo(7L)
+    }
+
     @Test
     fun `all-day task clears the timezone`() {
         val form = TaskForm(

app/src/test/java/de/jeanlucmakiola/floret/domain/TaskFormTest.kt

@@ -35,4 +35,13 @@ class TaskFormTest {
         val errors = TaskForm(title = "x", listId = 1, reminderMinutesBeforeDue = 10).validate()
         assertThat(errors).contains(TaskFormError.REMINDER_WITHOUT_DUE)
     }
+
+    @Test
+    fun `progress and parent auto-reveal only when they carry a value`() {
+        assertThat(TaskForm(title = "x", listId = 1).populatedFields()).isEmpty()
+        assertThat(TaskForm(title = "x", listId = 1, percentComplete = 0, parentId = 0).populatedFields())
+            .isEmpty()
+        assertThat(TaskForm(title = "x", listId = 1, percentComplete = 30, parentId = 9).populatedFields())
+            .containsExactly(TaskFormField.Progress, TaskFormField.Parent)
+    }
 }

app/src/test/java/de/jeanlucmakiola/floret/domain/TaskSectionsTest.kt

@@ -0,0 +1,47 @@
+package de.jeanlucmakiola.floret.domain
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.jupiter.api.Test
+import kotlin.time.Instant
+
+class TaskSectionsTest {
+
+    private val dayMs = 86_400_000L
+    private val todayStart = Instant.fromEpochMilliseconds(1000 * dayMs)
+    private val todayEnd = Instant.fromEpochMilliseconds(1001 * dayMs)
+
+    private fun at(millis: Long) = Instant.fromEpochMilliseconds(millis)
+    private fun sectionOf(task: Task) = TaskSections.sectionOf(task, todayStart, todayEnd)
+
+    @Test
+    fun `buckets by due relative to today`() {
+        assertThat(sectionOf(testTask(due = at(1000 * dayMs - 1)))).isEqualTo(TaskSection.OVERDUE)
+        assertThat(sectionOf(testTask(due = at(1000 * dayMs + 1)))).isEqualTo(TaskSection.TODAY)
+        assertThat(sectionOf(testTask(due = at(1001 * dayMs + 1)))).isEqualTo(TaskSection.UPCOMING)
+        assertThat(sectionOf(testTask(due = null))).isEqualTo(TaskSection.NO_DATE)
+    }
+
+    @Test
+    fun `completed always lands in completed regardless of due`() {
+        val overdueButDone = testTask(status = TaskStatus.COMPLETED, due = at(1000 * dayMs - 1))
+        assertThat(sectionOf(overdueButDone)).isEqualTo(TaskSection.COMPLETED)
+    }
+
+    @Test
+    fun `of returns only non-empty sections in fixed order`() {
+        val tasks = listOf(
+            testTask(id = 1, due = at(1001 * dayMs + 1)),   // upcoming
+            testTask(id = 2, due = at(1000 * dayMs - 1)),   // overdue
+            testTask(id = 3, status = TaskStatus.COMPLETED), // completed
+        )
+        val sections = TaskSections.of(tasks, todayStart, todayEnd)
+        assertThat(sections.map { it.section })
+            .containsExactly(TaskSection.OVERDUE, TaskSection.UPCOMING, TaskSection.COMPLETED)
+            .inOrder()
+    }
+
+    @Test
+    fun `empty input yields no sections`() {
+        assertThat(TaskSections.of(emptyList(), todayStart, todayEnd)).isEmpty()
+    }
+}

docs/ROADMAP.md

@@ -11,9 +11,12 @@ Status legend: ✅ done · 🚧 in progress · ⬜ not started
 ## Current state (one line)
 
 The full non-visual stack ("backoffice") over the OpenTasks `TaskContract`
-provider is **done and unit-tested**; the Material 3 Expressive UI is being
+provider is **done and unit-tested**, and the Material 3 Expressive UI is built
-built screen by screen on top of it. App builds, gates on provider/permission,
+through **M4**: lists → task list (swipe gestures, inline add, smart-list section
-and renders the lists overview.
+headers) → detail / edit with full CRUD, date-time pickers, priority,
+percent-complete, conflict-safe saves, per-task reminders, and subtask
+create + reparent. Remaining work is M5 (notification / exact-alarm onboarding,
+default reminder UI) and M6 (Settings screen, Glance widget, i18n, release).
 
 ---
 
@@ -39,36 +42,81 @@ The complete non-visual stack:
 - JVM unit tests across mappers, filtering, sorting, form, value mapping, and
   day windows.
 
-### 🚧 M2 — Screens: lists, task list, complete & CRUD
+### ✅ M2 — Screens: lists, task list, complete & CRUD
-Replace the functional scaffold with the real Material 3 Expressive UI, screen
+The real Material 3 Expressive UI, built screen by screen against the M1
-by screen, against the already-built ViewModels.
+ViewModels.
 - ✅ Provider/permission onboarding gate (`RootScreen`).
 - ✅ Lists overview (`ListsScreen`) — smart lists + user lists grouped by account.
-- 🚧 Navigation host wiring (the `onOpenFilter` / `onNewTask` callbacks in
+- ✅ Navigation host wiring (`FloretNavHost` + `Dest` route table: lists → task
-  `RootScreen` are currently stubs).
+  list → detail / edit, each binding its M1 ViewModel from route args).
-- ⬜ Task list screen — checkbox rows, swipe-to-complete / swipe-to-delete,
+- ✅ Task list screen — checkbox rows + toggle-complete, swipe-to-complete /
-  inline add field, section headers for smart lists, FAB.
+  -delete (`SwipeToDismissBox`), inline add field (`InlineAdd` → `quickAdd`),
-- ⬜ Toggle complete (swipe + checkbox), create / edit / delete, local-list
+  smart-list section headers (`TaskSections`).
-  creation wired to the UI.
+- ✅ Detail + edit screens — detail shows title / description / subtasks with
+  edit+delete; edit has the full CRUD form (title, description, save) wired to a
+  list picker.
 
-### ⬜ M3 — Detail / edit polish
+### ✅ M3 — Detail / edit polish
-Task detail and edit screens: due/start date-time pickers, priority,
+- ✅ Due / start date-time pickers (`DateTimePickerFlow` in `TaskEditScreen`).
-percent-complete, conflict-safe saves (re-check before overwrite), smart-list
+- ✅ Priority — coloured by level: green / amber / red pastels (`priorityFill`;
-section presentation.
+  M3 has no priority role, only `error`). A shared `ui/common/PriorityChip` on the
+  list and detail screens, and the edit form's M3 segmented selector tints its
+  active segment in the chosen level's hue.
+- ✅ Smart-list section presentation (`TaskSections` headers on the task list).
+- ✅ Percent-complete field — optional "Progress" slider (5% detents) on the edit
+  form; writes `Tasks.PERCENT_COMPLETE` (clamped 0–100, status left to the
+  complete toggle).
+- ✅ Conflict-safe saves — `updateTask` re-checks `last_modified` against the
+  value captured when the form loaded and throws `TaskConflictException`; the
+  editor offers overwrite-or-cancel instead of clobbering an external change.
 
-### ⬜ M4 — Subtasks (UI)
+### ✅ M4 — Subtasks (UI)
-`RELATED-TO` hierarchy in the UI: indentation, create subtask, reparent. The
+`RELATED-TO` hierarchy in the UI. The data layer already reads `parentId`.
-data layer already reads `parentId`; this is the trickiest UI piece.
+- ✅ Create subtask (`AddSubtaskField` → `TaskDetailViewModel.addSubtask` sets
+  `parentId`); subtasks render as a grouped section in the detail screen. Tapping
+  a subtask opens its own detail (a new `TaskDetail` entry, so it can have
+  children too), and the subtask's detail shows a tappable "Part of …" parent
+  card so it never reads as a stray standalone task.
+- ✅ Inline expansion on the task list — a parent row has a dedicated expand
+  button (trailing chevron, separate from the count chip). Each section flattens
+  into one grouped run (parents + their expanded children) and corners are chosen
+  per-edge (`cornerPosition`): top-level tasks keep their own run, an expanded
+  parent opens its bottom to its children, and the child group rounds off on its
+  last segment while the next top-level task stays mid-run. Children are
+  full-width, set a step down in tone (`surfaceContainer` vs the parents'
+  `surfaceContainerHigh`) and with no colour bar (checkbox stays aligned). An expanded group ends with an inline "add a subtask"
+  row (always on for now; an opt-out toggle lands with the M6 settings screen).
+  Offered only where the list holds all the children (a real list; smart lists
+  that omit off-day children stay collapsed). `TaskDetail.parent` carries the
+  parent for the detail card.
+- ✅ Reparent — a full-width, searchable "Parent task" sheet on the edit form
+  groups active candidates by due-date section (Overdue / Today / Upcoming / No
+  date) and files a task under any top-level task in its list (or "None" to
+  promote it); switching list clears the now-invalid parent. Candidates stay
+  active + top-level to keep nesting one level deep, matching the detail screen.
 
-### ⬜ M5 — Reminders onboarding & polish
+### 🚧 M5 — Reminders onboarding & polish
-The engine exists (M1). Remaining: the `POST_NOTIFICATIONS` + exact-alarm
+The engine exists (M1: `ReminderScheduler` + boot / provider-change re-sync,
-onboarding flow, per-task / default reminder-offset settings UI, and
+`DueReminderReceiver`, `TaskNotifier`).
-end-to-end verification on device.
+- ✅ Per-task reminder-offset UI (`ReminderPickerDialog` → `TaskForm`
+  `reminderMinutesBeforeDue`).
+- ⬜ `POST_NOTIFICATIONS` + exact-alarm onboarding flow — currently only graceful
+  runtime checks (`TaskNotifier.canPost`, `canScheduleExactAlarms`), no
+  user-facing gate.
+- ⬜ Default reminder-offset settings UI — `SettingsPrefs`/`SettingsViewModel`
+  back it, but no Composable exposes it.
+- ⬜ End-to-end verification on device.
 
-### ⬜ M6 — Settings, widget, i18n, release
+### 🚧 M6 — Settings, widget, i18n, release
-Settings screen (theme / dynamic-color / language, default list, default
+- ✅ F-Droid metadata scaffolded (`fdroid-metadata/`).
-reminder), Glance task-list widget, translations, finalize F-Droid metadata,
+- ⬜ Settings screen — `SettingsViewModel` exists but no `SettingsScreen`
-confirm CI release flow.
+  Composable and it is not in the nav graph (only used by `MainActivity` for
+  app-level theming). Needs theme / dynamic-color / language, default list,
+  default reminder, and the opt-out toggle for the task list's inline
+  add-a-subtask row (on by default since M4).
+- ⬜ Glance task-list widget — deps present in `build.gradle.kts`, zero impl.
+- ⬜ Translations — only `res/values/` (English); no `values-XX`.
+- ⬜ Finalize F-Droid metadata, confirm CI release flow.
 
 ### ⬜ Posture B (separate track, later)
 Add a `:provider` module bundling the Apache-2.0 `opentasks-provider`;

gradle/libs.versions.toml

@@ -22,6 +22,7 @@ kotlinxDatetime = "0.7.0"
 kotlinxCoroutines = "1.10.2"
 turbine = "1.2.0"
 hiltNavigationCompose = "1.3.0"
+navigationCompose = "2.9.0"
 lifecycleCompose = "2.10.0"
 androidxTestRules = "1.7.0"
 # Glance: 1.1.1 is the latest stable (1.2.0 is still rc, 1.3.0 alpha).
@@ -78,6 +79,9 @@ turbine = { group = "app.cash.turbine", name = "turbine", version.ref = "turbine
 # Hilt navigation-compose (for hiltViewModel() in Composables)
 androidx-hilt-navigation-compose = { group = "androidx.hilt", name = "hilt-navigation-compose", version.ref = "hiltNavigationCompose" }
 
+# Navigation-compose (the NavHost / back stack)
+androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }
+
 # Lifecycle compose (for collectAsStateWithLifecycle)
 androidx-lifecycle-runtime-compose = { group = "androidx.lifecycle", name = "lifecycle-runtime-compose", version.ref = "lifecycleCompose" }