diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 7df196f..32abcd2 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -10,15 +10,19 @@
         android:supportsRtl="true"
         android:theme="@style/Theme.YaYa">
         <activity
-            android:name=".MainActivity"
+            android:name=".SplashActivity"
             android:exported="true"
-            android:theme="@style/Theme.YaYa.Starting">
+            android:theme="@style/Theme.YaYa.Splash">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
 
+        <activity
+            android:name=".MainActivity"
+            android:exported="true" />
+
         <activity
             android:name=".AboutActivity"
             android:exported="false" />
diff --git a/app/src/main/kotlin/plus/rua/project/MainActivity.kt b/app/src/main/kotlin/plus/rua/project/MainActivity.kt
index 6ea86af..f9a24a4 100644
--- a/app/src/main/kotlin/plus/rua/project/MainActivity.kt
+++ b/app/src/main/kotlin/plus/rua/project/MainActivity.kt
@@ -4,13 +4,11 @@ import android.content.Intent
 import android.os.Bundle
 import androidx.activity.compose.ReportDrawn
 import androidx.activity.compose.setContent
-import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
 import plus.rua.project.ui.CalendarMonthView
 import plus.rua.project.ui.theme.YaYaTheme
 
 class MainActivity : BaseActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
-        installSplashScreen()
         super.onCreate(savedInstanceState)
 
         setContent {
diff --git a/app/src/main/kotlin/plus/rua/project/SplashActivity.kt b/app/src/main/kotlin/plus/rua/project/SplashActivity.kt
new file mode 100644
index 0000000..0042805
--- /dev/null
+++ b/app/src/main/kotlin/plus/rua/project/SplashActivity.kt
@@ -0,0 +1,43 @@
+package plus.rua.project
+
+import android.content.Intent
+import android.os.Bundle
+import androidx.activity.compose.setContent
+import androidx.compose.ui.res.painterResource
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import plus.rua.project.ui.SplashScreen
+import plus.rua.project.ui.theme.YaYaTheme
+
+private const val SPLASH_DELAY_MS = 400L
+
+/**
+ * 启动页 Activity。
+ *
+ * 显示品牌启动图 400ms 后跳转到 [MainActivity]，并 finish 自身。
+ */
+class SplashActivity : BaseActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        setContent {
+            YaYaTheme {
+                SplashScreen(
+                    iconPainter = painterResource(R.mipmap.ic_launcher),
+                )
+            }
+        }
+
+        lifecycleScope.launch {
+            delay(SPLASH_DELAY_MS)
+            navigateToMain()
+        }
+    }
+
+    private fun navigateToMain() {
+        if (isFinishing) return
+        startActivityWithSlide(Intent(this, MainActivity::class.java))
+        finish()
+    }
+}
diff --git a/app/src/main/res/values-night/themes.xml b/app/src/main/res/values-night/themes.xml
index 6138c74..58abbfb 100644
--- a/app/src/main/res/values-night/themes.xml
+++ b/app/src/main/res/values-night/themes.xml
@@ -2,8 +2,15 @@
 <resources>
     <style name="Theme.YaYa" parent="@android:style/Theme.Material.NoActionBar" />
 
+    <!--
+        启动主题：用于 MAIN/LAUNCHER Activity。
+    -->
     <style name="Theme.YaYa.Starting" parent="Theme.SplashScreen">
-        <item name="windowSplashScreenBackground">@drawable/launch_bg</item>
+        <item name="windowSplashScreenBackground">@color/splash_background</item>
         <item name="postSplashScreenTheme">@style/Theme.YaYa</item>
     </style>
+
+    <style name="Theme.YaYa.Splash" parent="@android:style/Theme.Material.NoActionBar">
+        <item name="android:windowBackground">@color/splash_background</item>
+    </style>
 </resources>
diff --git a/app/src/main/res/values/themes.xml b/app/src/main/res/values/themes.xml
index e498332..2297d58 100644
--- a/app/src/main/res/values/themes.xml
+++ b/app/src/main/res/values/themes.xml
@@ -5,10 +5,15 @@
     <!--
         启动主题：用于 MAIN/LAUNCHER Activity。
         继承 Theme.SplashScreen，保证 Android 12 以下也能获得一致的启动窗口行为。
-        windowSplashScreenBackground 使用启动背景图作为窗口背景。
+        windowSplashScreenBackground 使用 Material 3 静态基准色，作为动态颜色不可用时
+        的 fallback，以减少启动窗口与 Compose 首帧之间的色差闪烁。
     -->
     <style name="Theme.YaYa.Starting" parent="Theme.SplashScreen">
-        <item name="windowSplashScreenBackground">@drawable/launch_bg</item>
+        <item name="windowSplashScreenBackground">@color/splash_background</item>
         <item name="postSplashScreenTheme">@style/Theme.YaYa</item>
     </style>
+
+    <style name="Theme.YaYa.Splash" parent="@android:style/Theme.Material.Light.NoActionBar">
+        <item name="android:windowBackground">@color/splash_background</item>
+    </style>
 </resources>
diff --git a/core/src/main/kotlin/plus/rua/project/ui/SplashScreen.kt b/core/src/main/kotlin/plus/rua/project/ui/SplashScreen.kt
new file mode 100644
index 0000000..89932c7
--- /dev/null
+++ b/core/src/main/kotlin/plus/rua/project/ui/SplashScreen.kt
@@ -0,0 +1,64 @@
+package plus.rua.project.ui
+
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.statusBars
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.painter.Painter
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalConfiguration
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.unit.dp
+import plus.rua.project.shared.R as CoreR
+
+private val SplashIconSize = 80.dp
+
+/**
+ * 品牌启动页 UI。
+ *
+ * 背景图铺满全屏，Light/Dark 资源由 Android 根据配置自动选择。
+ * app icon 水平居中，其垂直中心位于状态栏下方可用区域高度的约 25% 处。
+ * 图片仅用于装饰，因此 contentDescription 为 null。
+ *
+ * @param iconPainter app icon 的 Painter
+ * @param modifier 外部传入的 Modifier
+ */
+@Composable
+fun SplashScreen(
+    iconPainter: Painter,
+    modifier: Modifier = Modifier,
+) {
+    val configuration = LocalConfiguration.current
+    val density = LocalDensity.current
+    val screenHeightDp = configuration.screenHeightDp.dp
+    val statusBarHeight = with(density) { WindowInsets.statusBars.getTop(this).toDp() }
+    val availableHeight = screenHeightDp - statusBarHeight
+    val iconTopPadding = statusBarHeight + (availableHeight * 0.25f) - (SplashIconSize / 2)
+
+    Box(
+        modifier = modifier.fillMaxSize(),
+    ) {
+        Image(
+            painter = painterResource(CoreR.drawable.launch_bg),
+            contentDescription = null,
+            contentScale = ContentScale.Crop,
+            modifier = Modifier.fillMaxSize(),
+        )
+
+        Image(
+            painter = iconPainter,
+            contentDescription = null,
+            modifier = Modifier
+                .align(Alignment.TopCenter)
+                .padding(top = iconTopPadding.coerceAtLeast(statusBarHeight))
+                .size(SplashIconSize),
+        )
+    }
+}