diff --git a/docs/deploy-checklist.md b/docs/deploy-checklist.md
index 01a2146..0b20399 100644
--- a/docs/deploy-checklist.md
+++ b/docs/deploy-checklist.md
@@ -38,12 +38,11 @@ Phase 1 **A~C** 이후 실행 트랙. 작업 단위를 하나씩 처리한다.
 - 앱 코드는 클로즈드 베타 직전 수준
 - **`https://msn.iykyka.com` 라이브 + N3 완료 + Gemini 실초안 OK + Track A/B 완료**
 - 진행 중: **N4 FCM 코드 경로** → Master 시크릿 대기 → Android UI QA
-- UI: **Soft Neutral + surface hierarchy** 프로덕션 반영 (`e05a0f0`, 2026-08-03) —
-  GitHub+Gitea `main` 듀얼 푸시 · `msn.iykyka.com` web 재빌드 완료
-- **Track C 콘텐츠 갭**: C1(단톡 따라잡기) **완료** (2026-08-03, 아직 GitHub `main`에만 있고
-  프로덕션 미배포) — 그룹 생성 UI, 안 본 동안 요약(`GET /conversations/:id/summary`), 읽음
-  마커, 안 본 배지, 그룹 트윈 발송 서버측 차단까지. 다음은 C2(관계별 페르소나) → C3(스팸 감지).
-  Master 액션(FCM 시크릿, 실기기 탭, 웹 재배포)과 별개로 계속 진행 가능
+- UI: **iMessage-inspired light default** + soft charcoal dark —
+  기본 `ThemeMode.light`, 내 버블 `#007AFF`, 다크 캔버스 `#141418` (배포 진행)
+- **Track C 콘텐츠 갭**: C1(단톡 따라잡기) **완료** (2026-08-03) — 그룹 생성 UI,
+  안 본 동안 요약(`GET /conversations/:id/summary`), 읽음 마커, 안 본 배지,
+  그룹 트윈 발송 서버측 차단까지. 다음은 C2(관계별 페르소나) → C3(스팸 감지).
 - 실 FCM 기기 수신 · Android 실기기 탭 · 사람 PoC 실행은 남음
 
 ### NEXT 순서
diff --git a/mobile/lib/main.dart b/mobile/lib/main.dart
index c57a988..8f69ffa 100644
--- a/mobile/lib/main.dart
+++ b/mobile/lib/main.dart
@@ -89,7 +89,8 @@ class _BootstrapState extends State<_Bootstrap> {
         debugShowCheckedModeBanner: false,
         theme: AppTheme.light(),
         darkTheme: AppTheme.dark(),
-        themeMode: ThemeMode.system,
+        // Default to light messenger UI; OS dark still maps to soft charcoal.
+        themeMode: ThemeMode.light,
         builder: (context, child) => GradientBackdrop(child: child),
         home: const SplashScreen(),
       );
@@ -112,7 +113,8 @@ class YkavuApp extends StatelessWidget {
         debugShowCheckedModeBanner: false,
         theme: AppTheme.light(),
         darkTheme: AppTheme.dark(),
-        themeMode: ThemeMode.system,
+        // Default to light messenger UI; OS dark still maps to soft charcoal.
+        themeMode: ThemeMode.light,
         builder: (context, child) => GradientBackdrop(child: child),
         home: Consumer<SessionState>(
           builder: (context, s, _) {
diff --git a/mobile/lib/screens/chat_screen.dart b/mobile/lib/screens/chat_screen.dart
index 849a87f..dc9e3d8 100644
--- a/mobile/lib/screens/chat_screen.dart
+++ b/mobile/lib/screens/chat_screen.dart
@@ -492,30 +492,43 @@ class _ChatScreenState extends State<ChatScreen> {
           ),
           _buildL1Panel(context),
           SafeArea(
-            child: Padding(
-              padding: const EdgeInsets.fromLTRB(12, 8, 12, 12),
+            child: Container(
+              padding: const EdgeInsets.fromLTRB(10, 8, 10, 10),
+              decoration: BoxDecoration(
+                color: AppTheme.glassFill(theme.brightness),
+                border: Border(
+                  top: BorderSide(color: AppTheme.glassBorder(theme.brightness).withValues(alpha: 0.7)),
+                ),
+              ),
               child: Row(
                 crossAxisAlignment: CrossAxisAlignment.end,
                 children: [
+                  IconButton(
+                    tooltip: '초안 요청',
+                    onPressed: _busy ? null : _requestDraft,
+                    icon: const Icon(Icons.auto_awesome_outlined),
+                  ),
                   Expanded(
                     child: TextField(
                       controller: _input,
                       minLines: 1,
                       maxLines: 4,
+                      textInputAction: TextInputAction.send,
+                      onSubmitted: (_) {
+                        if (!_busy) _sendHuman();
+                      },
                       decoration: const InputDecoration(hintText: '메시지'),
                     ),
                   ),
-                  const SizedBox(width: 8),
-                  IconButton.filledTonal(
-                    tooltip: '초안 요청',
-                    onPressed: _busy ? null : _requestDraft,
-                    icon: const Icon(Icons.auto_awesome),
-                  ),
-                  const SizedBox(width: 4),
+                  const SizedBox(width: 6),
                   IconButton.filled(
                     tooltip: '보내기',
                     onPressed: _busy ? null : _sendHuman,
-                    icon: const Icon(Icons.send),
+                    style: IconButton.styleFrom(
+                      backgroundColor: theme.colorScheme.primary,
+                      foregroundColor: theme.colorScheme.onPrimary,
+                    ),
+                    icon: const Icon(Icons.arrow_upward_rounded),
                   ),
                 ],
               ),
diff --git a/mobile/lib/screens/conversation_list_screen.dart b/mobile/lib/screens/conversation_list_screen.dart
index aabd03e..e8a367b 100644
--- a/mobile/lib/screens/conversation_list_screen.dart
+++ b/mobile/lib/screens/conversation_list_screen.dart
@@ -205,16 +205,16 @@ class _ConversationListScreenState extends State<ConversationListScreen> {
   Color _avatarColor(BuildContext context, int seed) {
     final isDark = Theme.of(context).brightness == Brightness.dark;
     final palette = isDark
-        ? const [Color(0xFF1C1C1C), Color(0xFF22262E), Color(0xFF242018)]
-        : const [Color(0xFFF4F4F5), Color(0xFFE8EEF4), Color(0xFFF3F0EA)];
+        ? const [Color(0xFF2C2C34), Color(0xFF243447), Color(0xFF3A3224)]
+        : const [Color(0xFFE9E9EB), Color(0xFFD6E8FF), Color(0xFFFFF1D6)];
     return palette[seed % palette.length];
   }
 
   Color _onAvatarColor(BuildContext context, int seed) {
     final isDark = Theme.of(context).brightness == Brightness.dark;
     final palette = isDark
-        ? const [Color(0xFFA3A3A3), Color(0xFF8BB4D9), Color(0xFFC4A574)]
-        : const [Color(0xFF525252), Color(0xFF3B6D9B), Color(0xFF9A7B4F)];
+        ? const [Color(0xFFF2F2F7), Color(0xFF0A84FF), Color(0xFFD4B06A)]
+        : const [Color(0xFF1C1C1E), Color(0xFF007AFF), Color(0xFFB08A4A)];
     return palette[seed % palette.length];
   }
 
diff --git a/mobile/lib/screens/signup_screen.dart b/mobile/lib/screens/signup_screen.dart
index cbcb2ae..cff5242 100644
--- a/mobile/lib/screens/signup_screen.dart
+++ b/mobile/lib/screens/signup_screen.dart
@@ -150,7 +150,7 @@ class _DemoTestPanel extends StatelessWidget {
               Text(
                 '테스트용 (누구나)',
                 style: theme.textTheme.labelLarge?.copyWith(
-                  color: theme.colorScheme.onSurfaceVariant,
+                  color: theme.colorScheme.primary,
                   letterSpacing: 0.15,
                   fontWeight: FontWeight.w600,
                 ),
diff --git a/mobile/lib/screens/splash_screen.dart b/mobile/lib/screens/splash_screen.dart
index e43ad4a..5e1d39b 100644
--- a/mobile/lib/screens/splash_screen.dart
+++ b/mobile/lib/screens/splash_screen.dart
@@ -36,8 +36,8 @@ class SplashScreen extends StatelessWidget {
               width: 22,
               height: 22,
               child: CircularProgressIndicator(
-                strokeWidth: 2,
-                color: scheme.onSurfaceVariant,
+                strokeWidth: 2.2,
+                color: scheme.primary,
               ),
             ),
           ],
diff --git a/mobile/lib/theme/app_theme.dart b/mobile/lib/theme/app_theme.dart
index 878bd6e..58308f1 100644
--- a/mobile/lib/theme/app_theme.dart
+++ b/mobile/lib/theme/app_theme.dart
@@ -1,36 +1,36 @@
 import 'package:flutter/material.dart';
 import 'package:google_fonts/google_fonts.dart';
 
-/// Soft Neutral + surface hierarchy for 와카뷰.
-/// Neutrals dominate; accent is thin (mine bubbles / small links only).
-/// Radii: input/button 12, bubble 18. No glow, almost no shadow.
+/// Messenger UI for 와카뷰 — iMessage-inspired light default + soft charcoal dark.
+/// Light: white stage, blue mine bubbles, gray peer bubbles.
+/// Dark: elevated charcoal (not pure black), softer blue accents.
 class AppTheme {
   AppTheme._();
 
-  // Light neutrals
-  static const canvasLight = Color(0xFFFAFAF9);
+  // Light — iOS Messages / white messenger
+  static const canvasLight = Color(0xFFF2F2F7);
   static const surfaceLight = Color(0xFFFFFFFF);
-  static const inkLight = Color(0xFF171717);
-  static const mutedLight = Color(0xFF737373);
-  static const lineLight = Color(0xFFE5E5E5);
-  static const softFillLight = Color(0xFFF4F4F5);
+  static const inkLight = Color(0xFF1C1C1E);
+  static const mutedLight = Color(0xFF8E8E93);
+  static const lineLight = Color(0xFFD1D1D6);
+  static const softFillLight = Color(0xFFE9E9EB);
 
-  // Dark neutrals
-  static const canvasDark = Color(0xFF0A0A0A);
-  static const surfaceDark = Color(0xFF141414);
-  static const inkDark = Color(0xFFFAFAFA);
-  static const mutedDark = Color(0xFFA3A3A3);
-  static const lineDark = Color(0xFF262626);
-  static const softFillDark = Color(0xFF1C1C1C);
+  // Dark — soft charcoal (not #000)
+  static const canvasDark = Color(0xFF141418);
+  static const surfaceDark = Color(0xFF1C1C22);
+  static const inkDark = Color(0xFFF2F2F7);
+  static const mutedDark = Color(0xFF98989F);
+  static const lineDark = Color(0xFF2C2C34);
+  static const softFillDark = Color(0xFF2C2C34);
 
-  /// Thin accent — used for mine bubbles & primary actions, not chrome.
-  static const accentLight = Color(0xFF3B6D9B);
-  static const accentDark = Color(0xFF8BB4D9);
-  static const accentSoftLight = Color(0xFFE8F0F7);
-  static const accentSoftDark = Color(0xFF1A2836);
+  /// iMessage-like blue for mine bubbles & primary actions.
+  static const accentLight = Color(0xFF007AFF);
+  static const accentDark = Color(0xFF0A84FF);
+  static const accentSoftLight = Color(0xFFD6E8FF);
+  static const accentSoftDark = Color(0xFF163A66);
 
-  static const twinAmberLight = Color(0xFF9A7B4F);
-  static const twinAmberDark = Color(0xFFC4A574);
+  static const twinAmberLight = Color(0xFFB08A4A);
+  static const twinAmberDark = Color(0xFFD4B06A);
 
   /// Compat for older call sites.
   static const teal = accentLight;
@@ -44,21 +44,26 @@ class AppTheme {
 
   static LinearGradient backgroundGradient(Brightness b) {
     final c = b == Brightness.dark ? canvasDark : canvasLight;
-    return LinearGradient(colors: [c, c]);
+    return LinearGradient(
+      begin: Alignment.topCenter,
+      end: Alignment.bottomCenter,
+      colors: [c, c],
+    );
   }
 
   static Color glassFill(Brightness b) => b == Brightness.dark ? surfaceDark : surfaceLight;
   static Color glassBorder(Brightness b) => b == Brightness.dark ? lineDark : lineLight;
   static Color glassShadow(Brightness b) => Colors.transparent;
 
-  static Color mineBubble(Brightness b) => b == Brightness.dark ? accentSoftDark : accentLight;
-  static Color mineBubbleFg(Brightness b) => b == Brightness.dark ? inkDark : Colors.white;
+  /// Mine = solid messenger blue (both modes).
+  static Color mineBubble(Brightness b) => b == Brightness.dark ? accentDark : accentLight;
+  static Color mineBubbleFg(Brightness b) => Colors.white;
   static Color peerBubble(Brightness b) => b == Brightness.dark ? softFillDark : softFillLight;
 
-  static const rInput = 12.0;
-  static const rButton = 12.0;
-  static const rBubble = 18.0;
-  static const rPanel = 12.0;
+  static const rInput = 20.0;
+  static const rButton = 14.0;
+  static const rBubble = 20.0;
+  static const rPanel = 14.0;
 
   static ThemeData light() => _build(Brightness.light);
   static ThemeData dark() => _build(Brightness.dark);
@@ -66,11 +71,10 @@ class AppTheme {
   static ThemeData _build(Brightness brightness) {
     final isDark = brightness == Brightness.dark;
     final primary = isDark ? accentDark : accentLight;
-    final onPrimary = isDark ? canvasDark : Colors.white;
+    final onPrimary = Colors.white;
     final ink = isDark ? inkDark : inkLight;
     final muted = isDark ? mutedDark : mutedLight;
     final line = isDark ? lineDark : lineLight;
-    final canvas = isDark ? canvasDark : canvasLight;
     final surface = isDark ? surfaceDark : surfaceLight;
     final soft = isDark ? softFillDark : softFillLight;
 
@@ -86,7 +90,7 @@ class AppTheme {
       onSecondaryContainer: muted,
       tertiary: primary,
       onTertiary: onPrimary,
-      error: isDark ? const Color(0xFFF87171) : const Color(0xFFB91C1C),
+      error: isDark ? const Color(0xFFFF6961) : const Color(0xFFFF3B30),
       onError: Colors.white,
       surface: surface,
       onSurface: ink,
@@ -109,12 +113,12 @@ class AppTheme {
       textTheme: textTheme,
       primaryTextTheme: textTheme,
       appBarTheme: AppBarTheme(
-        backgroundColor: canvas.withValues(alpha: 0.92),
+        backgroundColor: surface.withValues(alpha: isDark ? 0.94 : 0.88),
         foregroundColor: ink,
         surfaceTintColor: Colors.transparent,
         elevation: 0,
         scrolledUnderElevation: 0,
-        centerTitle: false,
+        centerTitle: true,
         titleTextStyle: textTheme.titleLarge?.copyWith(fontWeight: FontWeight.w600, letterSpacing: -0.2),
       ),
       cardTheme: CardThemeData(
@@ -122,32 +126,32 @@ class AppTheme {
         color: surface,
         shape: RoundedRectangleBorder(
           borderRadius: BorderRadius.circular(rPanel),
-          side: BorderSide(color: line),
+          side: BorderSide(color: line.withValues(alpha: isDark ? 0.9 : 0.65)),
         ),
         margin: EdgeInsets.zero,
       ),
       listTileTheme: ListTileThemeData(
         iconColor: muted,
         shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(rPanel)),
-        contentPadding: const EdgeInsets.symmetric(horizontal: 14, vertical: 2),
-        minVerticalPadding: 8,
+        contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
+        minVerticalPadding: 10,
       ),
-      dividerTheme: DividerThemeData(color: line, space: 1, thickness: 1),
+      dividerTheme: DividerThemeData(color: line, space: 1, thickness: 0.5),
       inputDecorationTheme: InputDecorationTheme(
         filled: true,
-        fillColor: surface,
-        contentPadding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
+        fillColor: isDark ? soft : surface,
+        contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
         border: OutlineInputBorder(
           borderRadius: BorderRadius.circular(rInput),
-          borderSide: BorderSide(color: line),
+          borderSide: BorderSide(color: line.withValues(alpha: 0.7)),
         ),
         enabledBorder: OutlineInputBorder(
           borderRadius: BorderRadius.circular(rInput),
-          borderSide: BorderSide(color: line),
+          borderSide: BorderSide(color: line.withValues(alpha: 0.7)),
         ),
         focusedBorder: OutlineInputBorder(
           borderRadius: BorderRadius.circular(rInput),
-          borderSide: BorderSide(color: primary, width: 1.2),
+          borderSide: BorderSide(color: primary, width: 1.4),
         ),
         errorBorder: OutlineInputBorder(
           borderRadius: BorderRadius.circular(rInput),
@@ -155,29 +159,29 @@ class AppTheme {
         ),
         focusedErrorBorder: OutlineInputBorder(
           borderRadius: BorderRadius.circular(rInput),
-          borderSide: BorderSide(color: scheme.error, width: 1.2),
+          borderSide: BorderSide(color: scheme.error, width: 1.4),
         ),
-        hintStyle: TextStyle(color: muted.withValues(alpha: 0.8)),
+        hintStyle: TextStyle(color: muted.withValues(alpha: 0.85)),
         labelStyle: TextStyle(color: muted, fontWeight: FontWeight.w500),
       ),
       filledButtonTheme: FilledButtonThemeData(
         style: FilledButton.styleFrom(
-          backgroundColor: isDark ? inkDark : inkLight,
-          foregroundColor: isDark ? canvasDark : Colors.white,
+          backgroundColor: primary,
+          foregroundColor: onPrimary,
           padding: const EdgeInsets.symmetric(horizontal: 18, vertical: 12),
-          minimumSize: const Size(0, 46),
+          minimumSize: const Size(0, 48),
           shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(rButton)),
-          textStyle: const TextStyle(fontWeight: FontWeight.w600, fontSize: 15),
+          textStyle: const TextStyle(fontWeight: FontWeight.w600, fontSize: 16),
           elevation: 0,
         ),
       ),
       outlinedButtonTheme: OutlinedButtonThemeData(
         style: OutlinedButton.styleFrom(
-          foregroundColor: ink,
+          foregroundColor: primary,
           padding: const EdgeInsets.symmetric(horizontal: 18, vertical: 12),
-          minimumSize: const Size(0, 46),
+          minimumSize: const Size(0, 48),
           shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(rButton)),
-          side: BorderSide(color: line),
+          side: BorderSide(color: primary.withValues(alpha: 0.45)),
         ),
       ),
       textButtonTheme: TextButtonThemeData(
@@ -188,22 +192,22 @@ class AppTheme {
       ),
       iconButtonTheme: IconButtonThemeData(
         style: IconButton.styleFrom(
-          foregroundColor: muted,
-          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
+          foregroundColor: primary,
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
         ),
       ),
       chipTheme: ChipThemeData(
-        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
         side: BorderSide(color: line),
-        backgroundColor: surface,
-        labelStyle: TextStyle(color: muted, fontWeight: FontWeight.w500, fontSize: 12),
+        backgroundColor: soft,
+        labelStyle: TextStyle(color: ink, fontWeight: FontWeight.w500, fontSize: 12),
         padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
       ),
       floatingActionButtonTheme: FloatingActionButtonThemeData(
-        backgroundColor: isDark ? inkDark : inkLight,
-        foregroundColor: isDark ? canvasDark : Colors.white,
+        backgroundColor: primary,
+        foregroundColor: onPrimary,
         elevation: 0,
-        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(rButton)),
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(18)),
       ),
       snackBarTheme: SnackBarThemeData(
         behavior: SnackBarBehavior.floating,
@@ -216,20 +220,20 @@ class AppTheme {
         backgroundColor: surface,
         elevation: 0,
         shape: RoundedRectangleBorder(
-          borderRadius: BorderRadius.circular(16),
-          side: BorderSide(color: line),
+          borderRadius: BorderRadius.circular(18),
+          side: BorderSide(color: line.withValues(alpha: 0.8)),
         ),
       ),
       progressIndicatorTheme: ProgressIndicatorThemeData(color: primary),
       bannerTheme: MaterialBannerThemeData(backgroundColor: surface, padding: const EdgeInsets.all(16)),
       segmentedButtonTheme: SegmentedButtonThemeData(
         style: SegmentedButton.styleFrom(
-          backgroundColor: surface,
+          backgroundColor: soft,
           foregroundColor: muted,
-          selectedForegroundColor: ink,
-          selectedBackgroundColor: soft,
-          side: BorderSide(color: line),
-          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(rButton)),
+          selectedForegroundColor: primary,
+          selectedBackgroundColor: isDark ? accentSoftDark : accentSoftLight,
+          side: BorderSide.none,
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
           padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 8),
         ),
       ),
@@ -241,16 +245,16 @@ class AppTheme {
         (t ?? const TextStyle()).copyWith(color: ink, fontWeight: w, fontSize: size, letterSpacing: ls, height: h);
 
     return base.copyWith(
-      displayLarge: s(base.displayLarge, w: FontWeight.w600, size: 36, ls: -1.0),
-      displaySmall: s(base.displaySmall, w: FontWeight.w600, size: 28, ls: -0.6),
-      headlineSmall: s(base.headlineSmall, w: FontWeight.w600, size: 20, ls: -0.2),
+      displayLarge: s(base.displayLarge, w: FontWeight.w700, size: 34, ls: -0.8),
+      displaySmall: s(base.displaySmall, w: FontWeight.w700, size: 28, ls: -0.5),
+      headlineSmall: s(base.headlineSmall, w: FontWeight.w600, size: 22, ls: -0.3),
       titleLarge: s(base.titleLarge, w: FontWeight.w600, size: 17, ls: -0.2),
-      titleMedium: s(base.titleMedium, w: FontWeight.w600, size: 15),
-      titleSmall: s(base.titleSmall, w: FontWeight.w600, size: 14),
-      bodyLarge: s(base.bodyLarge, w: FontWeight.w400, size: 15, h: 1.45),
-      bodyMedium: s(base.bodyMedium, w: FontWeight.w400, size: 14, h: 1.45),
-      bodySmall: s(base.bodySmall, w: FontWeight.w400, size: 12, h: 1.4),
-      labelLarge: s(base.labelLarge, w: FontWeight.w500, size: 13),
+      titleMedium: s(base.titleMedium, w: FontWeight.w600, size: 16),
+      titleSmall: s(base.titleSmall, w: FontWeight.w600, size: 15),
+      bodyLarge: s(base.bodyLarge, w: FontWeight.w400, size: 17, h: 1.35),
+      bodyMedium: s(base.bodyMedium, w: FontWeight.w400, size: 16, h: 1.35),
+      bodySmall: s(base.bodySmall, w: FontWeight.w400, size: 13, h: 1.35),
+      labelLarge: s(base.labelLarge, w: FontWeight.w500, size: 15),
       labelSmall: s(base.labelSmall, w: FontWeight.w500, size: 11),
     );
   }
diff --git a/mobile/lib/widgets/brand_mark.dart b/mobile/lib/widgets/brand_mark.dart
index 962226c..f9637e2 100644
--- a/mobile/lib/widgets/brand_mark.dart
+++ b/mobile/lib/widgets/brand_mark.dart
@@ -2,7 +2,7 @@ import 'package:flutter/material.dart';
 
 import '../theme/app_theme.dart';
 
-/// Soft Neutral brand mark — ink monogram, no glow or heavy tile chrome.
+/// Compact messenger brand mark — blue tile, no glow.
 class BrandMark extends StatelessWidget {
   const BrandMark({super.key, this.size = 64});
 
@@ -10,21 +10,19 @@ class BrandMark extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final fill = isDark ? AppTheme.inkDark : AppTheme.inkLight;
-    final fg = isDark ? AppTheme.canvasDark : Colors.white;
+    final scheme = Theme.of(context).colorScheme;
     return Container(
       width: size,
       height: size,
       decoration: BoxDecoration(
-        color: fill,
-        borderRadius: BorderRadius.circular(AppTheme.rPanel),
+        color: scheme.primary,
+        borderRadius: BorderRadius.circular(size * 0.28),
       ),
       alignment: Alignment.center,
       child: Text(
         'Y',
         style: TextStyle(
-          color: fg,
+          color: scheme.onPrimary,
           fontWeight: FontWeight.w700,
           fontSize: size * 0.42,
           height: 1,
diff --git a/mobile/lib/widgets/message_bubble.dart b/mobile/lib/widgets/message_bubble.dart
index 8ef3a4f..cf4b3f1 100644
--- a/mobile/lib/widgets/message_bubble.dart
+++ b/mobile/lib/widgets/message_bubble.dart
@@ -3,7 +3,7 @@ import 'package:flutter/material.dart';
 import '../models/models.dart';
 import '../theme/app_theme.dart';
 
-/// Twin messages get a warm thin border + label (PRD §3.1 와카뷰 뱃지).
+/// iMessage-like bubble. Twin messages keep a warm label + soft tint (PRD §3.1).
 class MessageBubble extends StatelessWidget {
   const MessageBubble({
     super.key,
@@ -34,23 +34,20 @@ class MessageBubble extends StatelessWidget {
 
     final Color bg;
     final Color fg;
-    Border? border;
     if (retracted) {
       bg = scheme.surfaceContainerHigh;
       fg = scheme.onSurfaceVariant;
     } else if (twin) {
       bg = brightness == Brightness.dark
-          ? const Color(0xFF221C14)
-          : const Color(0xFFFAF6F0);
+          ? const Color(0xFF2A2418)
+          : const Color(0xFFFFF6E8);
       fg = scheme.onSurface;
-      border = Border.all(color: accent.withValues(alpha: 0.4), width: 1);
     } else if (isMine) {
       bg = AppTheme.mineBubble(brightness);
       fg = AppTheme.mineBubbleFg(brightness);
     } else {
       bg = AppTheme.peerBubble(brightness);
       fg = scheme.onSurface;
-      border = Border.all(color: scheme.outlineVariant.withValues(alpha: 0.9));
     }
 
     final radius = BorderRadius.only(
@@ -61,12 +58,12 @@ class MessageBubble extends StatelessWidget {
     );
 
     final bubble = Container(
-      constraints: BoxConstraints(maxWidth: MediaQuery.sizeOf(context).width * 0.76),
-      padding: const EdgeInsets.fromLTRB(14, 10, 14, 8),
+      constraints: BoxConstraints(maxWidth: MediaQuery.sizeOf(context).width * 0.74),
+      padding: const EdgeInsets.fromLTRB(14, 9, 14, 7),
       decoration: BoxDecoration(
         color: bg,
         borderRadius: radius,
-        border: border,
+        border: twin ? Border.all(color: accent.withValues(alpha: 0.35)) : null,
       ),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
@@ -74,13 +71,13 @@ class MessageBubble extends StatelessWidget {
         children: [
           if (twin)
             Padding(
-              padding: const EdgeInsets.only(bottom: 4),
+              padding: const EdgeInsets.only(bottom: 3),
               child: Text(
                 '와카뷰',
                 style: theme.textTheme.labelSmall?.copyWith(
                   color: accent,
                   fontWeight: FontWeight.w700,
-                  letterSpacing: 0.2,
+                  letterSpacing: 0.15,
                 ),
               ),
             ),
@@ -99,12 +96,15 @@ class MessageBubble extends StatelessWidget {
           else
             Text(
               message.text,
-              style: theme.textTheme.bodyMedium?.copyWith(color: fg, height: 1.4),
+              style: theme.textTheme.bodyMedium?.copyWith(color: fg, height: 1.3),
             ),
-          const SizedBox(height: 4),
+          const SizedBox(height: 3),
           Text(
             _time(message.createdAt),
-            style: theme.textTheme.labelSmall?.copyWith(color: fg.withValues(alpha: 0.55), fontSize: 10),
+            style: theme.textTheme.labelSmall?.copyWith(
+              color: fg.withValues(alpha: isMine && !twin && !retracted ? 0.7 : 0.5),
+              fontSize: 10,
+            ),
           ),
         ],
       ),
@@ -135,7 +135,7 @@ class MessageBubble extends StatelessWidget {
     );
 
     return Padding(
-      padding: const EdgeInsets.symmetric(vertical: 3, horizontal: 12),
+      padding: const EdgeInsets.symmetric(vertical: 2, horizontal: 10),
       child: Align(
         alignment: isMine ? Alignment.centerRight : Alignment.centerLeft,
         child: content,
diff --git a/mobile/lib/widgets/primary_gradient_button.dart b/mobile/lib/widgets/primary_gradient_button.dart
index 7e9519c..83175f7 100644
--- a/mobile/lib/widgets/primary_gradient_button.dart
+++ b/mobile/lib/widgets/primary_gradient_button.dart
@@ -2,7 +2,7 @@ import 'package:flutter/material.dart';
 
 import '../theme/app_theme.dart';
 
-/// Primary CTA — Soft Neutral ink fill (API name kept for call sites).
+/// Primary CTA — messenger blue fill (API name kept for call sites).
 class PrimaryGradientButton extends StatelessWidget {
   const PrimaryGradientButton({
     super.key,
@@ -17,12 +17,12 @@ class PrimaryGradientButton extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final bg = isDark ? AppTheme.inkDark : AppTheme.inkLight;
-    final fg = isDark ? AppTheme.canvasDark : Colors.white;
+    final scheme = Theme.of(context).colorScheme;
+    final bg = scheme.primary;
+    final fg = scheme.onPrimary;
     final disabled = onPressed == null || loading;
     return SizedBox(
-      height: 48,
+      height: 50,
       width: double.infinity,
       child: FilledButton(
         onPressed: disabled && !loading ? null : onPressed,
@@ -44,7 +44,7 @@ class PrimaryGradientButton extends StatelessWidget {
               )
             : Text(
                 label,
-                style: TextStyle(color: fg, fontWeight: FontWeight.w600, fontSize: 15),
+                style: TextStyle(color: fg, fontWeight: FontWeight.w600, fontSize: 16),
               ),
       ),
     );