diff --git a/app/src/main/java/com/inspection/camera/data/PreferencesManager.kt b/app/src/main/java/com/inspection/camera/data/PreferencesManager.kt
index df1500f..ead0254 100644
--- a/app/src/main/java/com/inspection/camera/data/PreferencesManager.kt
+++ b/app/src/main/java/com/inspection/camera/data/PreferencesManager.kt
@@ -11,6 +11,7 @@ import androidx.datastore.preferences.preferencesDataStore
 import com.inspection.camera.data.models.ImageQuality
 import com.inspection.camera.data.models.LocationMode
 import com.inspection.camera.data.models.MergeLayoutType
+import com.inspection.camera.data.models.ThemeMode
 import com.inspection.camera.data.models.WatermarkStyle
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
@@ -34,6 +35,7 @@ class PreferencesManager(private val context: Context) {
         private val KEY_MERGE_CONTENT = stringPreferencesKey("merge_content")
         private val KEY_RECORDER_NAME = stringPreferencesKey("recorder_name")
         private val KEY_FILE_NAME_TEMPLATE = stringPreferencesKey("file_name_template")
+        private val KEY_THEME_MODE = stringPreferencesKey("theme_mode")
     }
 
     val watermarkStyle: Flow<WatermarkStyle> = context.dataStore.data.map { prefs ->
@@ -109,6 +111,15 @@ class PreferencesManager(private val context: Context) {
         prefs[KEY_FILE_NAME_TEMPLATE] ?: "{project}_{inspector}_{date}"
     }
 
+    val themeMode: Flow<ThemeMode> = context.dataStore.data.map { prefs ->
+        val mode = prefs[KEY_THEME_MODE] ?: ThemeMode.FOLLOW_SYSTEM.name
+        try {
+            ThemeMode.valueOf(mode)
+        } catch (e: Exception) {
+            ThemeMode.FOLLOW_SYSTEM
+        }
+    }
+
     suspend fun setWatermarkStyle(style: WatermarkStyle) {
         context.dataStore.edit { prefs ->
             prefs[KEY_WATERMARK_STYLE] = style.name
@@ -180,4 +191,10 @@ class PreferencesManager(private val context: Context) {
             prefs[KEY_FILE_NAME_TEMPLATE] = template
         }
     }
+
+    suspend fun setThemeMode(mode: ThemeMode) {
+        context.dataStore.edit { prefs ->
+            prefs[KEY_THEME_MODE] = mode.name
+        }
+    }
 }
diff --git a/app/src/main/java/com/inspection/camera/data/models/WatermarkModels.kt b/app/src/main/java/com/inspection/camera/data/models/WatermarkModels.kt
index 8aefb0d..cfb8d4e 100644
--- a/app/src/main/java/com/inspection/camera/data/models/WatermarkModels.kt
+++ b/app/src/main/java/com/inspection/camera/data/models/WatermarkModels.kt
@@ -64,3 +64,9 @@ enum class MergeLayoutType(val rows: Int, val cols: Int, val displayName: String
     Grid2x2(2, 2, "2x2网格", 4),
     Grid3x3(3, 3, "3x3网格", 9)
 }
+
+enum class ThemeMode {
+    FOLLOW_SYSTEM,
+    LIGHT,
+    DARK
+}
diff --git a/app/src/main/java/com/inspection/camera/ui/MainActivity.kt b/app/src/main/java/com/inspection/camera/ui/MainActivity.kt
index 99831a8..04d7604 100644
--- a/app/src/main/java/com/inspection/camera/ui/MainActivity.kt
+++ b/app/src/main/java/com/inspection/camera/ui/MainActivity.kt
@@ -17,6 +17,7 @@ import androidx.compose.material3.NavigationBarItem
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 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
@@ -31,6 +32,7 @@ import androidx.navigation.compose.composable
 import androidx.navigation.compose.currentBackStackEntryAsState
 import androidx.navigation.compose.rememberNavController
 import com.inspection.camera.data.PreferencesManager
+import com.inspection.camera.data.models.ThemeMode
 import com.inspection.camera.ui.camera.CameraScreen
 import com.inspection.camera.ui.gallery.GalleryScreen
 import com.inspection.camera.ui.merge.MergeScreen
@@ -47,7 +49,13 @@ class MainActivity : ComponentActivity() {
         preferencesManager = PreferencesManager(this)
 
         setContent {
-            InspectionCameraTheme {
+            var themeMode by remember { mutableStateOf(ThemeMode.FOLLOW_SYSTEM) }
+
+            LaunchedEffect(Unit) {
+                preferencesManager.themeMode.collect { themeMode = it }
+            }
+
+            InspectionCameraTheme(themeMode = themeMode) {
                 MainApp(preferencesManager = preferencesManager)
             }
         }
diff --git a/app/src/main/java/com/inspection/camera/ui/gallery/GalleryScreen.kt b/app/src/main/java/com/inspection/camera/ui/gallery/GalleryScreen.kt
index da8ae64..70402be 100644
--- a/app/src/main/java/com/inspection/camera/ui/gallery/GalleryScreen.kt
+++ b/app/src/main/java/com/inspection/camera/ui/gallery/GalleryScreen.kt
@@ -58,7 +58,6 @@ import androidx.lifecycle.LifecycleEventObserver
 import androidx.lifecycle.LifecycleOwner
 import coil.compose.AsyncImage
 import coil.request.ImageRequest
-import com.inspection.camera.ui.theme.Primary
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -130,10 +129,10 @@ fun GalleryScreen(onNavigateBack: () -> Unit) {
                     }
                 },
                 colors = TopAppBarDefaults.topAppBarColors(
-                    containerColor = Primary,
-                    titleContentColor = Color.White,
-                    navigationIconContentColor = Color.White,
-                    actionIconContentColor = Color.White
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimary,
+                    navigationIconContentColor = MaterialTheme.colorScheme.onPrimary,
+                    actionIconContentColor = MaterialTheme.colorScheme.onPrimary
                 )
             )
         }
@@ -168,7 +167,7 @@ fun GalleryScreen(onNavigateBack: () -> Unit) {
                                 Box(
                                     modifier = Modifier.weight(1f).aspectRatio(1f)
                                         .clip(RoundedCornerShape(8.dp))
-                                        .background(Color.LightGray)
+                                        .background(MaterialTheme.colorScheme.surfaceVariant)
                                         .clickable {
                                             selectedImageUri = img.uri
                                         }
@@ -236,7 +235,7 @@ fun GalleryScreen(onNavigateBack: () -> Unit) {
                     Text("图片预览")
                     Row {
                         IconButton(onClick = { showDeleteConfirm = true }) {
-                            Icon(Icons.Default.Delete, contentDescription = "删除", tint = Color.Red)
+                            Icon(Icons.Default.Delete, contentDescription = "删除", tint = MaterialTheme.colorScheme.error)
                         }
                         IconButton(onClick = { selectedImageUri = null }) {
                             Icon(Icons.Default.Close, contentDescription = "关闭")
@@ -271,7 +270,7 @@ fun GalleryScreen(onNavigateBack: () -> Unit) {
                             showDeleteConfirm = false
                         }
                     }) {
-                        Text("确定删除", color = Color.Red)
+                        Text("确定删除", color = MaterialTheme.colorScheme.error)
                     }
                 },
                 dismissButton = {
@@ -293,7 +292,7 @@ private fun ZoomableImage(imageUri: Uri, modifier: Modifier = Modifier) {
     Box(
         modifier = modifier
             .clip(RoundedCornerShape(8.dp))
-            .background(Color.Black.copy(alpha = 0.05f))
+            .background(MaterialTheme.colorScheme.surfaceVariant)
             .pointerInput(Unit) {
                 detectTransformGestures { _, pan, zoom, _ ->
                     scale = (scale * zoom).coerceIn(1f, 5f)
diff --git a/app/src/main/java/com/inspection/camera/ui/merge/MergeScreen.kt b/app/src/main/java/com/inspection/camera/ui/merge/MergeScreen.kt
index e0cff9d..8456292 100644
--- a/app/src/main/java/com/inspection/camera/ui/merge/MergeScreen.kt
+++ b/app/src/main/java/com/inspection/camera/ui/merge/MergeScreen.kt
@@ -72,7 +72,6 @@ import com.inspection.camera.data.models.ImageItem
 import com.inspection.camera.data.models.ImageQuality
 import com.inspection.camera.data.models.MergeLayoutType
 import com.inspection.camera.data.models.WatermarkStyle
-import com.inspection.camera.ui.theme.Primary
 import com.inspection.camera.util.ImageProcessor
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
@@ -292,9 +291,9 @@ fun MergeScreen(
                     }
                 },
                 colors = TopAppBarDefaults.topAppBarColors(
-                    containerColor = Primary,
-                    titleContentColor = Color.White,
-                    navigationIconContentColor = Color.White
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimary,
+                    navigationIconContentColor = MaterialTheme.colorScheme.onPrimary
                 )
             )
         }
@@ -341,7 +340,7 @@ fun MergeScreen(
                 Text(
                     text = autoImportText,
                     style = MaterialTheme.typography.bodyMedium,
-                    color = Primary,
+                    color = MaterialTheme.colorScheme.primary,
                     modifier = Modifier
                         .fillMaxWidth()
                         .padding(horizontal = 16.dp, vertical = 12.dp)
@@ -365,13 +364,13 @@ fun MergeScreen(
                         Box(
                             modifier = Modifier
                                 .clip(RoundedCornerShape(4.dp))
-                                .background(if (imageQuality == quality) Primary else Color.LightGray)
+                                .background(if (imageQuality == quality) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.surfaceVariant)
                                 .clickable { imageQuality = quality }
                                 .padding(horizontal = 12.dp, vertical = 4.dp)
                         ) {
                             Text(
                                 text = quality.displayName,
-                                color = if (imageQuality == quality) Color.White else Color.Black,
+                                color = if (imageQuality == quality) MaterialTheme.colorScheme.onPrimary else MaterialTheme.colorScheme.onSurface,
                                 style = MaterialTheme.typography.bodySmall
                             )
                         }
@@ -403,7 +402,7 @@ fun MergeScreen(
                                                 .weight(1f)
                                                 .aspectRatio(1f)
                                                 .clip(RoundedCornerShape(8.dp))
-                                                .background(Color.LightGray)
+                                                .background(MaterialTheme.colorScheme.surfaceVariant)
                                                 .then(
                                                     if (index < images.size) {
                                                         Modifier.clickable {
@@ -435,12 +434,12 @@ fun MergeScreen(
                                                     modifier = Modifier
                                                         .align(Alignment.TopEnd)
                                                         .size(32.dp)
-                                                        .background(Color.Black.copy(alpha = 0.5f), CircleShape)
+                                                        .background(MaterialTheme.colorScheme.scrim.copy(alpha = 0.5f), CircleShape)
                                                 ) {
                                                     Icon(
                                                         Icons.Default.Close,
                                                         contentDescription = "删除",
-                                                        tint = Color.White,
+                                                        tint = MaterialTheme.colorScheme.onPrimary,
                                                         modifier = Modifier.size(16.dp)
                                                     )
                                                 }
@@ -448,7 +447,7 @@ fun MergeScreen(
                                                 Icon(
                                                     Icons.Default.Add,
                                                     contentDescription = "添加图片",
-                                                    tint = Color.Gray,
+                                                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
                                                     modifier = Modifier.size(48.dp)
                                                 )
                                             }
@@ -633,20 +632,20 @@ private fun LayoutOption(
     Box(
         modifier = Modifier
             .clip(RoundedCornerShape(8.dp))
-            .background(if (isSelected) Primary else Color.LightGray)
+            .background(if (isSelected) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.surfaceVariant)
             .clickable(onClick = onClick)
             .padding(12.dp)
-    ) {
-        Row(verticalAlignment = Alignment.CenterVertically) {
-            Text(
-                text = displayText,
-                color = if (isSelected) Color.White else Color.Black
+        ) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                Text(
+                    text = displayText,
+                    color = if (isSelected) MaterialTheme.colorScheme.onPrimary else MaterialTheme.colorScheme.onSurface
             )
             if (isSelected) {
-                Icon(
-                    Icons.Default.Check,
-                    contentDescription = null,
-                    tint = Color.White,
+                    Icon(
+                        Icons.Default.Check,
+                        contentDescription = null,
+                        tint = MaterialTheme.colorScheme.onPrimary,
                     modifier = Modifier.size(16.dp)
                 )
             }
diff --git a/app/src/main/java/com/inspection/camera/ui/settings/SettingsScreen.kt b/app/src/main/java/com/inspection/camera/ui/settings/SettingsScreen.kt
index 62bcfba..76e7ea3 100644
--- a/app/src/main/java/com/inspection/camera/ui/settings/SettingsScreen.kt
+++ b/app/src/main/java/com/inspection/camera/ui/settings/SettingsScreen.kt
@@ -35,14 +35,13 @@ import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
 import com.inspection.camera.data.PreferencesManager
 import com.inspection.camera.data.models.ImageQuality
 import com.inspection.camera.data.models.LocationMode
 import com.inspection.camera.data.models.MergeLayoutType
+import com.inspection.camera.data.models.ThemeMode
 import com.inspection.camera.data.models.WatermarkStyle
-import com.inspection.camera.ui.theme.Primary
 import kotlinx.coroutines.launch
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -61,6 +60,7 @@ fun SettingsScreen(
     var defaultTheme by remember { mutableStateOf("") }
     var recorderName by remember { mutableStateOf("") }
     var fileNameTemplate by remember { mutableStateOf("{project}_{inspector}_{date}") }
+    var themeMode by remember { mutableStateOf(ThemeMode.FOLLOW_SYSTEM) }
 
     // 加载配置
     scope.launch {
@@ -87,6 +87,9 @@ scope.launch {
 scope.launch {
     preferencesManager.fileNameTemplate.collect { fileNameTemplate = it }
 }
+scope.launch {
+    preferencesManager.themeMode.collect { themeMode = it }
+}
 
     Scaffold(
         topBar = {
@@ -114,13 +117,13 @@ scope.launch {
                         // 返回主界面
                         onNavigateBack()
                     }) {
-                        Text("保存", color = Color.White)
+                        Text("保存", color = MaterialTheme.colorScheme.onPrimary)
                     }
                 },
                 colors = TopAppBarDefaults.topAppBarColors(
-                    containerColor = Primary,
-                    titleContentColor = Color.White,
-                    navigationIconContentColor = Color.White
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimary,
+                    navigationIconContentColor = MaterialTheme.colorScheme.onPrimary
                 )
             )
         }
@@ -157,7 +160,7 @@ scope.launch {
                                     else -> ""
                                 },
                                 style = MaterialTheme.typography.bodySmall,
-                                color = Color.Gray,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
                                 modifier = Modifier.padding(start = 40.dp)
                             )
                         }
@@ -271,7 +274,7 @@ scope.launch {
                                     else -> ""
                                 },
                                 style = MaterialTheme.typography.bodySmall,
-                                color = Color.Gray,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
                                 modifier = Modifier.padding(start = 40.dp)
                             )
                         }
@@ -281,6 +284,34 @@ scope.launch {
 
             Spacer(modifier = Modifier.height(16.dp))
 
+            // 主题设置
+            SettingsSection(title = "主题设置") {
+                SettingsItem(title = "界面主题") {
+                    listOf(
+                        ThemeMode.FOLLOW_SYSTEM to "跟随系统",
+                        ThemeMode.LIGHT to "浅色模式",
+                        ThemeMode.DARK to "暗色模式"
+                    ).forEach { (mode, label) ->
+                        Row(
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .clickable { scope.launch { preferencesManager.setThemeMode(mode) } }
+                                .padding(vertical = 8.dp),
+                            verticalAlignment = Alignment.CenterVertically
+                        ) {
+                            RadioButton(
+                                selected = themeMode == mode,
+                                onClick = { scope.launch { preferencesManager.setThemeMode(mode) } }
+                            )
+                            Spacer(modifier = Modifier.width(8.dp))
+                            Text(label)
+                        }
+                    }
+                }
+            }
+
+            Spacer(modifier = Modifier.height(16.dp))
+
             // 通用设置
             SettingsSection(title = "通用设置") {
                 SettingsItem(title = "默认拼图标题") {
@@ -321,7 +352,7 @@ SettingsItem(title = "记录人信息") {
         Text(
             text = "可用占位符：{project} {device} {inspector} {date} {time}",
             style = MaterialTheme.typography.bodySmall,
-            color = Color.Gray
+            color = MaterialTheme.colorScheme.onSurfaceVariant
         )
     }
             }
@@ -349,13 +380,13 @@ private fun SettingsSection(
         modifier = Modifier
             .fillMaxWidth()
             .padding(horizontal = 16.dp),
-        colors = CardDefaults.cardColors(containerColor = Color.White)
+        colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surface)
     ) {
         Column(modifier = Modifier.padding(16.dp)) {
             Text(
                 text = title,
                 style = MaterialTheme.typography.titleMedium,
-                color = Primary
+                color = MaterialTheme.colorScheme.primary
             )
             Spacer(modifier = Modifier.height(8.dp))
             content()
diff --git a/app/src/main/java/com/inspection/camera/ui/theme/Theme.kt b/app/src/main/java/com/inspection/camera/ui/theme/Theme.kt
index 9df8972..5c6f10a 100644
--- a/app/src/main/java/com/inspection/camera/ui/theme/Theme.kt
+++ b/app/src/main/java/com/inspection/camera/ui/theme/Theme.kt
@@ -10,6 +10,7 @@ import androidx.compose.runtime.SideEffect
 import androidx.compose.ui.graphics.toArgb
 import androidx.compose.ui.platform.LocalView
 import androidx.core.view.WindowCompat
+import com.inspection.camera.data.models.ThemeMode
 
 private val LightColorScheme = lightColorScheme(
     primary = Primary,
@@ -37,10 +38,15 @@ private val DarkColorScheme = darkColorScheme(
 
 @Composable
 fun InspectionCameraTheme(
-    darkTheme: Boolean = isSystemInDarkTheme(),
+    themeMode: ThemeMode = ThemeMode.FOLLOW_SYSTEM,
     content: @Composable () -> Unit
 ) {
-    val colorScheme = if (darkTheme) DarkColorScheme else LightColorScheme
+    val isDark = when (themeMode) {
+        ThemeMode.FOLLOW_SYSTEM -> isSystemInDarkTheme()
+        ThemeMode.LIGHT -> false
+        ThemeMode.DARK -> true
+    }
+    val colorScheme = if (isDark) DarkColorScheme else LightColorScheme
     val view = LocalView.current
 
     if (!view.isInEditMode) {
diff --git a/docs/superpowers/plans/2026-05-13-theme-mode-plan.md b/docs/superpowers/plans/2026-05-13-theme-mode-plan.md
new file mode 100644
index 0000000..d7533f0
--- /dev/null
+++ b/docs/superpowers/plans/2026-05-13-theme-mode-plan.md
@@ -0,0 +1,519 @@
+# 主题模式切换 Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add theme mode toggle (follow-system/light/dark) and fix dark mode font visibility
+
+**Architecture:** Add ThemeMode enum + PreferencesManager storage, thread themeMode through InspectionCameraTheme, replace all hardcoded Color values with MaterialTheme.colorScheme.* across all screens
+
+**Tech Stack:** Jetpack Compose, Material3, DataStore Preferences
+
+---
+
+### Task 1: Add ThemeMode enum
+
+**Files:**
+- Modify: `app/src/main/java/com/inspection/camera/data/models/WatermarkModels.kt`
+
+- [ ] **Step 1: Add ThemeMode enum**
+
+Add after the existing enums at end of file:
+
+```kotlin
+enum class ThemeMode {
+    FOLLOW_SYSTEM,
+    LIGHT,
+    DARK
+}
+```
+
+- [ ] **Step 2: Verify compilation**
+
+Run: `cd android-CheckShot && ./gradlew :app:compileDebugKotlin`
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/data/models/WatermarkModels.kt
+git commit -m "feat: add ThemeMode enum (follow-system/light/dark)"
+```
+
+---
+
+### Task 2: Add themeMode to PreferencesManager
+
+**Files:**
+- Modify: `app/src/main/java/com/inspection/camera/data/PreferencesManager.kt`
+
+- [ ] **Step 1: Add KEY_THEME_MODE + themeMode Flow + setter**
+
+After `KEY_FILE_NAME_TEMPLATE` line, add:
+```kotlin
+private val KEY_THEME_MODE = stringPreferencesKey("theme_mode")
+```
+
+After `fileNameTemplate` Flow, add:
+```kotlin
+val themeMode: Flow<ThemeMode> = context.dataStore.data.map { prefs ->
+    val mode = prefs[KEY_THEME_MODE] ?: ThemeMode.FOLLOW_SYSTEM.name
+    try {
+        ThemeMode.valueOf(mode)
+    } catch (e: Exception) {
+        ThemeMode.FOLLOW_SYSTEM
+    }
+}
+```
+
+After `setFileNameTemplate`, add:
+```kotlin
+suspend fun setThemeMode(mode: ThemeMode) {
+    context.dataStore.edit { prefs ->
+        prefs[KEY_THEME_MODE] = mode.name
+    }
+}
+```
+
+Add import for ThemeMode above existing imports:
+```kotlin
+import com.inspection.camera.data.models.ThemeMode
+```
+
+- [ ] **Step 2: Verify compilation**
+
+Run: `cd android-CheckShot && ./gradlew :app:compileDebugKotlin`
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/data/PreferencesManager.kt
+git commit -m "feat: add themeMode preference to DataStore"
+```
+
+---
+
+### Task 3: Update InspectionCameraTheme to accept themeMode
+
+**Files:**
+- Modify: `app/src/main/java/com/inspection/camera/ui/theme/Theme.kt`
+
+- [ ] **Step 1: Replace darkTheme param with themeMode**
+
+Change the function signature from:
+```kotlin
+fun InspectionCameraTheme(
+    darkTheme: Boolean = isSystemInDarkTheme(),
+    content: @Composable () -> Unit
+)
+```
+to:
+```kotlin
+fun InspectionCameraTheme(
+    themeMode: ThemeMode = ThemeMode.FOLLOW_SYSTEM,
+    content: @Composable () -> Unit
+) {
+    val isDark = when (themeMode) {
+        ThemeMode.FOLLOW_SYSTEM -> isSystemInDarkTheme()
+        ThemeMode.LIGHT -> false
+        ThemeMode.DARK -> true
+    }
+    val colorScheme = if (isDark) DarkColorScheme else LightColorScheme
+    // ... rest stays the same
+}
+```
+
+Also remove the old `darkTheme: Boolean = isSystemInDarkTheme()` parameter and the `val colorScheme = if (darkTheme) DarkColorScheme else LightColorScheme` line since it's now inside the function.
+
+Add import:
+```kotlin
+import com.inspection.camera.data.models.ThemeMode
+```
+
+The final function should look like:
+```kotlin
+@Composable
+fun InspectionCameraTheme(
+    themeMode: ThemeMode = ThemeMode.FOLLOW_SYSTEM,
+    content: @Composable () -> Unit
+) {
+    val isDark = when (themeMode) {
+        ThemeMode.FOLLOW_SYSTEM -> isSystemInDarkTheme()
+        ThemeMode.LIGHT -> false
+        ThemeMode.DARK -> true
+    }
+    val colorScheme = if (isDark) DarkColorScheme else LightColorScheme
+    // ... rest unchanged
+}
+```
+
+- [ ] **Step 2: Verify compilation**
+
+Run: `cd android-CheckShot && ./gradlew :app:compileDebugKotlin`
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/ui/theme/Theme.kt
+git commit -m "refactor: replace darkTheme param with themeMode in InspectionCameraTheme"
+```
+
+---
+
+### Task 4: Update MainActivity to pass themeMode
+
+**Files:**
+- Modify: `app/src/main/java/com/inspection/camera/ui/MainActivity.kt`
+
+- [ ] **Step 1: Read themeMode from PreferencesManager and pass to theme**
+
+Add `var themeMode` state variable and collect the Flow. Pass to `InspectionCameraTheme`:
+
+```kotlin
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.setValue
+import com.inspection.camera.data.models.ThemeMode
+
+class MainActivity : ComponentActivity() {
+    private lateinit var preferencesManager: PreferencesManager
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
+
+        preferencesManager = PreferencesManager(this)
+
+        setContent {
+            var themeMode by remember { mutableStateOf(ThemeMode.FOLLOW_SYSTEM) }
+
+            LaunchedEffect(Unit) {
+                preferencesManager.themeMode.collect { themeMode = it }
+            }
+
+            InspectionCameraTheme(themeMode = themeMode) {
+                MainApp(preferencesManager = preferencesManager)
+            }
+        }
+    }
+}
+```
+
+Remove `import androidx.compose.foundation.isSystemInDarkTheme` if it was previously used only through `InspectionCameraTheme`'s default.
+
+- [ ] **Step 2: Verify compilation**
+
+Run: `cd android-CheckShot && ./gradlew :app:compileDebugKotlin`
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/ui/MainActivity.kt
+git commit -m "feat: read themeMode preference and pass to InspectionCameraTheme"
+```
+
+---
+
+### Task 5: Add theme selector to SettingsScreen
+
+**Files:**
+- Modify: `app/src/main/java/com/inspection/camera/ui/settings/SettingsScreen.kt`
+
+- [ ] **Step 1: Add themeMode state and collect from preferences**
+
+Add state variable alongside existing ones:
+```kotlin
+var themeMode by remember { mutableStateOf(ThemeMode.FOLLOW_SYSTEM) }
+```
+
+Add collection logic:
+```kotlin
+scope.launch {
+    preferencesManager.themeMode.collect { themeMode = it }
+}
+```
+
+- [ ] **Step 2: Add theme section UI before "通用设置" section**
+
+Add before the "通用设置" section (before `Spacer(modifier = Modifier.height(16.dp))` that precedes `SettingsSection(title = "通用设置")`):
+
+```kotlin
+Spacer(modifier = Modifier.height(16.dp))
+
+// 主题设置
+SettingsSection(title = "主题设置") {
+    SettingsItem(title = "界面主题") {
+        listOf(
+            ThemeMode.FOLLOW_SYSTEM to "跟随系统",
+            ThemeMode.LIGHT to "浅色模式",
+            ThemeMode.DARK to "暗色模式"
+        ).forEach { (mode, label) ->
+            Row(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .clickable { scope.launch { preferencesManager.setThemeMode(mode) } }
+                    .padding(vertical = 8.dp),
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                RadioButton(
+                    selected = themeMode == mode,
+                    onClick = { scope.launch { preferencesManager.setThemeMode(mode) } }
+                )
+                Spacer(modifier = Modifier.width(8.dp))
+                Text(label)
+            }
+        }
+    }
+}
+```
+
+Replace hardcoded settings colors. Change `CardDefaults.cardColors(containerColor = Color.White)` (line 352):
+```kotlin
+colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surface)
+```
+
+Change section title `Primary` (line 358) to `MaterialTheme.colorScheme.primary`.
+
+Note: TopAppBar colors, description text colors, etc. will be fixed in Task 7 (global pass).
+
+Add import:
+```kotlin
+import com.inspection.camera.data.models.ThemeMode
+import androidx.compose.material3.MaterialTheme
+```
+
+- [ ] **Step 3: Verify compilation**
+
+Run: `cd android-CheckShot && ./gradlew :app:compileDebugKotlin`
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/ui/settings/SettingsScreen.kt
+git commit -m "feat: add theme selector UI to settings screen"
+```
+
+---
+
+### Task 6: Replace hardcoded colors in GalleryScreen
+
+**Files:**
+- Modify: `app/src/main/java/com/inspection/camera/ui/gallery/GalleryScreen.kt`
+
+- [ ] **Step 1: Replace color values**
+
+Replace TopAppBar colors (lines 132-137):
+```kotlin
+colors = TopAppBarDefaults.topAppBarColors(
+    containerColor = MaterialTheme.colorScheme.primary,
+    titleContentColor = MaterialTheme.colorScheme.onPrimary,
+    navigationIconContentColor = MaterialTheme.colorScheme.onPrimary,
+    actionIconContentColor = MaterialTheme.colorScheme.onPrimary
+)
+```
+
+Replace `Color.LightGray` placeholder background (line 171):
+```kotlin
+.background(MaterialTheme.colorScheme.surfaceVariant)
+```
+
+Replace `Color.Red` delete icon tint (line 239):
+```kotlin
+Icon(Icons.Default.Delete, contentDescription = "删除", tint = MaterialTheme.colorScheme.error)
+```
+
+Replace `Color.Red` delete button text (line 274):
+```kotlin
+Text("确定删除", color = MaterialTheme.colorScheme.error)
+```
+
+Replace `Color.Black.copy(alpha = 0.05f)` zoomable background (line 296):
+```kotlin
+.background(MaterialTheme.colorScheme.surfaceVariant)
+```
+
+Remove unused imports: `import com.inspection.camera.ui.theme.Primary`
+
+- [ ] **Step 2: Verify compilation**
+
+Run: `cd android-CheckShot && ./gradlew :app:compileDebugKotlin`
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/ui/gallery/GalleryScreen.kt
+git commit -m "fix: replace hardcoded colors with MaterialTheme.colorScheme in GalleryScreen"
+```
+
+---
+
+### Task 7: Replace hardcoded colors in MergeScreen
+
+**Files:**
+- Modify: `app/src/main/java/com/inspection/camera/ui/merge/MergeScreen.kt`
+
+- [ ] **Step 1: Replace color values**
+
+TopAppBar colors (lines 294-298):
+```kotlin
+colors = TopAppBarDefaults.topAppBarColors(
+    containerColor = MaterialTheme.colorScheme.primary,
+    titleContentColor = MaterialTheme.colorScheme.onPrimary,
+    navigationIconContentColor = MaterialTheme.colorScheme.onPrimary
+)
+```
+
+Auto-import text color (line 344):
+```kotlin
+color = MaterialTheme.colorScheme.primary
+```
+
+Quality/layout button backgrounds (lines 368, 636):
+```kotlin
+.background(if (imageQuality == quality) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.surfaceVariant)
+```
+
+Quality button text (line 374):
+```kotlin
+color = if (imageQuality == quality) MaterialTheme.colorScheme.onPrimary else MaterialTheme.colorScheme.onSurface
+```
+
+Placeholder background (line 406):
+```kotlin
+.background(MaterialTheme.colorScheme.surfaceVariant)
+```
+
+Selection overlay (line 438):
+```kotlin
+.background(MaterialTheme.colorScheme.scrim.copy(alpha = 0.5f), CircleShape)
+```
+
+Check icon tint (lines 443, 649):
+```kotlin
+tint = MaterialTheme.colorScheme.onPrimary
+```
+
+Add icon tint (line 451):
+```kotlin
+tint = MaterialTheme.colorScheme.onSurfaceVariant
+```
+
+Layout option backgrounds (line 636):
+```kotlin
+.background(if (isSelected) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.surfaceVariant)
+```
+
+Layout option text (line 643):
+```kotlin
+color = if (isSelected) MaterialTheme.colorScheme.onPrimary else MaterialTheme.colorScheme.onSurface
+```
+
+Remove unused import: `import com.inspection.camera.ui.theme.Primary`
+
+- [ ] **Step 2: Verify compilation**
+
+Run: `cd android-CheckShot && ./gradlew :app:compileDebugKotlin`
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/ui/merge/MergeScreen.kt
+git commit -m "fix: replace hardcoded colors with MaterialTheme.colorScheme in MergeScreen"
+```
+
+---
+
+### Task 8: Replace hardcoded colors in SettingsScreen (remaining)
+
+**Files:**
+- Modify: `app/src/main/java/com/inspection/camera/ui/settings/SettingsScreen.kt`
+
+- [ ] **Step 1: Replace remaining hardcoded colors**
+
+Save button text (line 117):
+```kotlin
+Text("保存", color = MaterialTheme.colorScheme.onPrimary)
+```
+
+TopAppBar colors (lines 120-124):
+```kotlin
+colors = TopAppBarDefaults.topAppBarColors(
+    containerColor = MaterialTheme.colorScheme.primary,
+    titleContentColor = MaterialTheme.colorScheme.onPrimary,
+    navigationIconContentColor = MaterialTheme.colorScheme.onPrimary
+)
+```
+
+Description text colors (lines 160, 274, 324):
+```kotlin
+color = MaterialTheme.colorScheme.onSurfaceVariant
+```
+
+```kotlin
+color = MaterialTheme.colorScheme.onSurfaceVariant
+```
+
+```kotlin
+color = MaterialTheme.colorScheme.onSurfaceVariant
+```
+
+Section title color (line 358) — already changed in Task 5 to `MaterialTheme.colorScheme.primary`.
+
+- [ ] **Step 2: Verify compilation**
+
+Run: `cd android-CheckShot && ./gradlew :app:compileDebugKotlin`
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/ui/settings/SettingsScreen.kt
+git commit -m "fix: replace hardcoded TopAppBar/card/description colors with MaterialTheme.colorScheme in SettingsScreen"
+```
+
+---
+
+### Task 9: Verify CameraScreen overlay colors unchanged
+
+**Files:**
+- Inspect: `app/src/main/java/com/inspection/camera/ui/camera/CameraScreen.kt`
+
+- [ ] **Step 1: Confirm camera overlay colors are preserved**
+
+CameraScreen uses semi-transparent overlays over the live camera preview:
+- `Color.Black.copy(alpha = 0.3f)` for top/bottom control bars
+- `Color.White` for FAB and icons
+- `Color.Black.copy(alpha = 0.6f)` for location card
+- `Color.Black.copy(alpha = 0.9f)` for flash effect
+
+These should remain as-is since they overlay live camera preview, not app background.
+
+- [ ] **Step 2: Optional — replace non-overlay colors if any are missed**
+
+The PermissionRequest composable uses no hardcoded colors that need changing (text with default style inherits from MaterialTheme).
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add app/src/main/java/com/inspection/camera/ui/camera/CameraScreen.kt
+git commit -m "chore: confirm CameraScreen overlay colors are correct for dark mode"
+```
+
+---
+
+### Verification: Full build
+
+- [ ] **Step 1: Full build**
+
+```bash
+cd android-CheckShot && ./gradlew :app:assembleDebug
+```
+Expected: BUILD SUCCESSFUL
+
+- [ ] **Step 2: Remove unused imports across all modified files**
+
+Ensure no unused imports remain (e.g., `import com.inspection.camera.ui.theme.Primary` removed from GalleryScreen, MergeScreen).
diff --git a/docs/superpowers/specs/2026-05-13-theme-mode-design.md b/docs/superpowers/specs/2026-05-13-theme-mode-design.md
new file mode 100644
index 0000000..015b925
--- /dev/null
+++ b/docs/superpowers/specs/2026-05-13-theme-mode-design.md
@@ -0,0 +1,75 @@
+# 主题模式切换功能设计
+
+## 概述
+为巡检相机 App 增加主题模式切换选项（跟随系统 / 浅色 / 暗色），
+并修复当前暗色模式下字体颜色不可读的问题。
+
+## 问题分析
+- Theme.kt 已定义 LightColorScheme 和 DarkColorScheme
+- 所有界面使用硬编码 Color 值（Color.White, Color.Black, Color.LightGray, Primary 等）
+- 未使用 MaterialTheme.colorScheme.*
+- 暗色模式下主题切换为 DarkColorScheme，但 UI 颜色不变，导致文字不可见
+
+## 方案：MaterialTheme.colorScheme 统一替换
+将所有硬编码颜色替换为 MaterialTheme.colorScheme 提供的语义化颜色。
+
+### 新增类型
+
+**ThemeMode 枚举**（data/models 包）
+```kotlin
+enum class ThemeMode {
+    FOLLOW_SYSTEM,
+    LIGHT,
+    DARK
+}
+```
+
+### 修改文件
+
+| 文件 | 改动 |
+|------|------|
+| `data/models/WatermarkModels.kt` | 新增 ThemeMode 枚举 |
+| `data/PreferencesManager.kt` | 新增 KEY_THEME_MODE + themeMode Flow + setThemeMode |
+| `ui/theme/Theme.kt` | InspectionCameraTheme 接受 themeMode 参数，取代 darkTheme |
+| `ui/MainActivity.kt` | 读取 themeMode 偏好并传入 InspectionCameraTheme |
+| `ui/settings/SettingsScreen.kt` | 新增"主题设置"区域，三个 RadioButton |
+| `ui/camera/CameraScreen.kt` | 替换硬编码颜色 |
+| `ui/gallery/GalleryScreen.kt` | 替换硬编码颜色 |
+| `ui/merge/MergeScreen.kt` | 替换硬编码颜色 |
+
+### 颜色替换映射
+
+| 原硬编码颜色 | 替换为 | 说明 |
+|-------------|--------|------|
+| `Primary` | `MaterialTheme.colorScheme.primary` | TopAppBar 背景、选中态、强调文字 |
+| `Color.White` (TopAppBar文字) | `MaterialTheme.colorScheme.onPrimary` | TopAppBar 文字/图标 |
+| `Color.White` (Card背景) | `MaterialTheme.colorScheme.surface` | Card 容器背景 |
+| `Color.LightGray` (占位背景) | `MaterialTheme.colorScheme.surfaceVariant` | 网格占位区背景 |
+| `Color.Gray` (辅助文字) | `MaterialTheme.colorScheme.onSurfaceVariant` | 描述性文字 |
+| `Color.Black` (primary文字) | `MaterialTheme.colorScheme.onSurface` | 主要文字 |
+| `Color.Red` (删除) | `MaterialTheme.colorScheme.error` | 删除/错误提示 |
+| `Color.White` (按钮文字) | `MaterialTheme.colorScheme.onPrimary` | 按钮文字 |
+| 相机覆盖层颜色 | 保持原样（覆盖在相机预览上，不属于主题背景） | 半透明黑/白色 |
+
+### 相机覆盖层的例外处理
+- 相机界面的半透明黑色底部控制栏（`Color.Black.copy(alpha = 0.3f)`）和白色 FAB 按钮**保持不变**
+- 这些元素覆盖在相机实时预览之上，不属于 App 背景层，不应随主题变化
+
+### 主题传递流程
+
+```
+SettingsScreen → PreferencesManager.setThemeMode(mode)
+    ↓
+MainActivity ← PreferencesManager.themeMode (Flow)
+    ↓
+InspectionCameraTheme(themeMode) → 计算是否暗色
+    ↓
+MaterialTheme(colorScheme = light/dark)
+    ↓
+所有界面使用 MaterialTheme.colorScheme.* 获取颜色
+```
+
+### ThemeMode 逻辑
+- `FOLLOW_SYSTEM`: `isSystemInDarkTheme()` 决定
+- `LIGHT`: 强制用 LightColorScheme
+- `DARK`: 强制用 DarkColorScheme