diff --git a/mobile/lib/main.dart b/mobile/lib/main.dart
index 3b35f5c..81a65cf 100644
--- a/mobile/lib/main.dart
+++ b/mobile/lib/main.dart
@@ -5,6 +5,7 @@ import 'screens/conversation_list_screen.dart';
 import 'screens/onboarding_tone_screen.dart';
 import 'screens/signup_screen.dart';
 import 'state/session_state.dart';
+import 'theme/app_theme.dart';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -24,13 +25,10 @@ class BunsinApp extends StatelessWidget {
       value: session,
       child: MaterialApp(
         title: '분신',
-        theme: ThemeData(
-          colorScheme: ColorScheme.fromSeed(
-            seedColor: const Color(0xFF1F6F5B),
-            brightness: Brightness.light,
-          ),
-          useMaterial3: true,
-        ),
+        debugShowCheckedModeBanner: false,
+        theme: AppTheme.light(),
+        darkTheme: AppTheme.dark(),
+        themeMode: ThemeMode.system,
         home: Consumer<SessionState>(
           builder: (context, s, _) {
             if (s.user == null) return const SignupScreen();
diff --git a/mobile/lib/screens/autonomy_settings_screen.dart b/mobile/lib/screens/autonomy_settings_screen.dart
index 9954a05..d153824 100644
--- a/mobile/lib/screens/autonomy_settings_screen.dart
+++ b/mobile/lib/screens/autonomy_settings_screen.dart
@@ -49,36 +49,50 @@ class _AutonomySettingsScreenState extends State<AutonomySettingsScreen> {
     super.dispose();
   }
 
+  static const _levelDescriptions = {
+    AutonomyLevel.L0: '분신이 초안만 만들고, 발송은 항상 직접 합니다.',
+    AutonomyLevel.L1: '분신이 초안을 만들면 검토·수정 후 승인해야 보내집니다.',
+    AutonomyLevel.L2: '아래 화이트리스트 주제는 승인 없이 자동으로 보내집니다.',
+  };
+
   @override
   Widget build(BuildContext context) {
     final session = context.watch<SessionState>();
+    final theme = Theme.of(context);
 
     return Scaffold(
       appBar: AppBar(title: const Text('자율성 설정')),
       body: ListView(
-        padding: const EdgeInsets.all(16),
+        padding: const EdgeInsets.fromLTRB(16, 8, 16, 32),
         children: [
-          ListTile(
-            contentPadding: EdgeInsets.zero,
-            leading: const Icon(Icons.privacy_tip_outlined),
-            title: const Text('데이터 흐름'),
-            subtitle: const Text('무엇이 기기에 남고 서버로 가는지'),
-            onTap: () {
-              Navigator.of(context).push(MaterialPageRoute(builder: (_) => const DataFlowScreen()));
-            },
+          Card(
+            child: Column(
+              children: [
+                ListTile(
+                  leading: const Icon(Icons.privacy_tip_outlined),
+                  title: const Text('데이터 흐름'),
+                  subtitle: const Text('무엇이 기기에 남고 서버로 가는지'),
+                  trailing: const Icon(Icons.chevron_right),
+                  onTap: () {
+                    Navigator.of(context).push(MaterialPageRoute(builder: (_) => const DataFlowScreen()));
+                  },
+                ),
+                const Divider(height: 1, indent: 16, endIndent: 16),
+                ListTile(
+                  leading: const Icon(Icons.devices),
+                  title: const Text('로그인 세션'),
+                  subtitle: const Text('멀티 디바이스 세션 목록'),
+                  trailing: const Icon(Icons.chevron_right),
+                  onTap: () {
+                    Navigator.of(context).push(MaterialPageRoute(builder: (_) => const SessionsScreen()));
+                  },
+                ),
+              ],
+            ),
           ),
-          ListTile(
-            contentPadding: EdgeInsets.zero,
-            leading: const Icon(Icons.devices),
-            title: const Text('로그인 세션'),
-            subtitle: const Text('멀티 디바이스 세션 목록'),
-            onTap: () {
-              Navigator.of(context).push(MaterialPageRoute(builder: (_) => const SessionsScreen()));
-            },
-          ),
-          const Divider(height: 32),
-          Text('전역 레벨', style: Theme.of(context).textTheme.titleMedium),
-          const SizedBox(height: 8),
+          const SizedBox(height: 24),
+          Text('전역 자율성 레벨', style: theme.textTheme.titleMedium),
+          const SizedBox(height: 12),
           SegmentedButton<AutonomyLevel>(
             segments: const [
               ButtonSegment(value: AutonomyLevel.L0, label: Text('L0'), tooltip: '초안만'),
@@ -88,23 +102,37 @@ class _AutonomySettingsScreenState extends State<AutonomySettingsScreen> {
             selected: {session.autonomyLevel},
             onSelectionChanged: (s) => session.setAutonomy(s.first),
           ),
-          const SizedBox(height: 8),
-          Text(
-            '기본값은 L0입니다. L2는 아래 화이트리스트 주제에만 자동 발송됩니다.',
-            style: Theme.of(context).textTheme.bodySmall,
+          const SizedBox(height: 10),
+          Container(
+            padding: const EdgeInsets.all(12),
+            decoration: BoxDecoration(
+              color: theme.colorScheme.surfaceContainerHigh,
+              borderRadius: BorderRadius.circular(12),
+            ),
+            child: Row(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Icon(Icons.info_outline, size: 18, color: theme.colorScheme.onSurfaceVariant),
+                const SizedBox(width: 8),
+                Expanded(
+                  child: Text(
+                    _levelDescriptions[session.autonomyLevel] ?? '',
+                    style: theme.textTheme.bodySmall?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+                  ),
+                ),
+              ],
+            ),
           ),
-          const Divider(height: 32),
-          Text('L2 화이트리스트 주제', style: Theme.of(context).textTheme.titleMedium),
-          const SizedBox(height: 8),
+          const SizedBox(height: 28),
+          Text('L2 화이트리스트 주제', style: theme.textTheme.titleMedium),
+          const SizedBox(height: 12),
           Row(
+            crossAxisAlignment: CrossAxisAlignment.start,
             children: [
               Expanded(
                 child: TextField(
                   controller: _keyword,
-                  decoration: const InputDecoration(
-                    labelText: '주제 키워드',
-                    border: OutlineInputBorder(),
-                  ),
+                  decoration: const InputDecoration(labelText: '주제 키워드'),
                 ),
               ),
               const SizedBox(width: 8),
@@ -128,24 +156,37 @@ class _AutonomySettingsScreenState extends State<AutonomySettingsScreen> {
           ),
           if (_error != null) ...[
             const SizedBox(height: 8),
-            Text(_error!, style: TextStyle(color: Theme.of(context).colorScheme.error)),
+            Text(_error!, style: TextStyle(color: theme.colorScheme.error)),
           ],
           const SizedBox(height: 12),
           if (_loading)
-            const Center(child: CircularProgressIndicator())
-          else
-            ..._rules.map(
-              (r) => ListTile(
-                title: Text(r.topicKeyword),
-                trailing: IconButton(
-                  icon: const Icon(Icons.delete_outline),
-                  onPressed: () async {
-                    if (session.user == null) return;
-                    await session.api.deleteWhitelist(session.user!.id, r.id);
-                    setState(() => _rules = _rules.where((x) => x.id != r.id).toList());
-                  },
-                ),
+            const Padding(
+              padding: EdgeInsets.symmetric(vertical: 24),
+              child: Center(child: CircularProgressIndicator()),
+            )
+          else if (_rules.isEmpty)
+            Padding(
+              padding: const EdgeInsets.symmetric(vertical: 16),
+              child: Text(
+                '아직 화이트리스트 주제가 없습니다.',
+                style: theme.textTheme.bodySmall?.copyWith(color: theme.colorScheme.onSurfaceVariant),
               ),
+            )
+          else
+            Wrap(
+              spacing: 8,
+              runSpacing: 8,
+              children: [
+                for (final r in _rules)
+                  InputChip(
+                    label: Text(r.topicKeyword),
+                    onDeleted: () async {
+                      if (session.user == null) return;
+                      await session.api.deleteWhitelist(session.user!.id, r.id);
+                      setState(() => _rules = _rules.where((x) => x.id != r.id).toList());
+                    },
+                  ),
+              ],
             ),
         ],
       ),
diff --git a/mobile/lib/screens/chat_screen.dart b/mobile/lib/screens/chat_screen.dart
index 0e62e99..52cba85 100644
--- a/mobile/lib/screens/chat_screen.dart
+++ b/mobile/lib/screens/chat_screen.dart
@@ -205,6 +205,18 @@ class _ChatScreenState extends State<ChatScreen> {
   }
 
   Future<void> _veto() async {
+    final ok = await showDialog<bool>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: const Text('거부권을 쓸까요?'),
+        content: const Text('이 대화방에서 분신 자동응대가 즉시 중단됩니다. 이후에는 다시 켤 수 없습니다.'),
+        actions: [
+          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('취소')),
+          FilledButton.tonal(onPressed: () => Navigator.pop(ctx, true), child: const Text('거부권 사용')),
+        ],
+      ),
+    );
+    if (ok != true || !mounted) return;
     final session = context.read<SessionState>();
     try {
       await session.api.vetoConversation(widget.conversationId);
@@ -229,74 +241,86 @@ class _ChatScreenState extends State<ChatScreen> {
     if (draft == null) return const SizedBox.shrink();
 
     if (draft.isEscalate) {
-      return Material(
-        color: theme.colorScheme.errorContainer,
-        child: Padding(
-          padding: const EdgeInsets.fromLTRB(16, 12, 16, 12),
-          child: Column(
-            crossAxisAlignment: CrossAxisAlignment.stretch,
-            children: [
-              Text('직접 확인 필요', style: theme.textTheme.titleSmall?.copyWith(fontWeight: FontWeight.w700)),
-              const SizedBox(height: 4),
-              Text(draft.text.isEmpty ? '민감·확정성 내용으로 분신 발송이 보류되었습니다.' : draft.text),
-              const SizedBox(height: 8),
-              Align(
-                alignment: Alignment.centerRight,
-                child: TextButton(onPressed: _rejectDraft, child: const Text('닫기')),
-              ),
-            ],
-          ),
+      return Container(
+        margin: const EdgeInsets.fromLTRB(12, 0, 12, 8),
+        padding: const EdgeInsets.all(16),
+        decoration: BoxDecoration(
+          color: theme.colorScheme.errorContainer,
+          borderRadius: BorderRadius.circular(16),
         ),
-      );
-    }
-
-    return Material(
-      elevation: 2,
-      color: theme.colorScheme.secondaryContainer,
-      child: Padding(
-        padding: const EdgeInsets.fromLTRB(16, 12, 16, 12),
         child: Column(
           crossAxisAlignment: CrossAxisAlignment.stretch,
           children: [
             Row(
               children: [
-                Icon(Icons.auto_awesome, size: 18, color: theme.colorScheme.onSecondaryContainer),
+                Icon(Icons.warning_amber_rounded, size: 18, color: theme.colorScheme.onErrorContainer),
                 const SizedBox(width: 6),
                 Text(
-                  'L1 승인 — 수정 후 보내기',
-                  style: theme.textTheme.titleSmall?.copyWith(fontWeight: FontWeight.w700),
+                  '직접 확인 필요',
+                  style: theme.textTheme.titleSmall?.copyWith(color: theme.colorScheme.onErrorContainer),
                 ),
               ],
             ),
-            const SizedBox(height: 8),
-            TextField(
-              controller: _draftEdit,
-              minLines: 2,
-              maxLines: 5,
-              decoration: const InputDecoration(
-                border: OutlineInputBorder(),
-                filled: true,
-                fillColor: Colors.white70,
-              ),
+            const SizedBox(height: 6),
+            Text(
+              draft.text.isEmpty ? '민감·확정성 내용으로 분신 발송이 보류되었습니다.' : draft.text,
+              style: TextStyle(color: theme.colorScheme.onErrorContainer),
             ),
-            const SizedBox(height: 8),
-            Row(
-              children: [
-                TextButton(onPressed: _busy ? null : _rejectDraft, child: const Text('버리기')),
-                const Spacer(),
-                FilledButton.tonal(
-                  onPressed: _busy ? null : _requestDraft,
-                  child: const Text('다시 초안'),
-                ),
-                const SizedBox(width: 8),
-                FilledButton(
-                  onPressed: _busy ? null : _sendTwinApproved,
-                  child: const Text('승인하고 보내기'),
-                ),
-              ],
+            const SizedBox(height: 4),
+            Align(
+              alignment: Alignment.centerRight,
+              child: TextButton(onPressed: _rejectDraft, child: const Text('닫기')),
             ),
           ],
         ),
+      );
+    }
+
+    return Container(
+      margin: const EdgeInsets.fromLTRB(12, 0, 12, 8),
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.colorScheme.secondaryContainer,
+        borderRadius: BorderRadius.circular(16),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.stretch,
+        children: [
+          Row(
+            children: [
+              Icon(Icons.auto_awesome, size: 18, color: theme.colorScheme.onSecondaryContainer),
+              const SizedBox(width: 6),
+              Text(
+                'L1 승인 — 수정 후 보내기',
+                style: theme.textTheme.titleSmall?.copyWith(color: theme.colorScheme.onSecondaryContainer),
+              ),
+            ],
+          ),
+          const SizedBox(height: 10),
+          TextField(
+            controller: _draftEdit,
+            minLines: 2,
+            maxLines: 5,
+            style: TextStyle(color: theme.colorScheme.onSurface),
+            decoration: InputDecoration(fillColor: theme.colorScheme.surface),
+          ),
+          const SizedBox(height: 10),
+          Row(
+            children: [
+              TextButton(onPressed: _busy ? null : _rejectDraft, child: const Text('버리기')),
+              const Spacer(),
+              FilledButton.tonal(
+                onPressed: _busy ? null : _requestDraft,
+                child: const Text('다시 초안'),
+              ),
+              const SizedBox(width: 8),
+              FilledButton(
+                onPressed: _busy ? null : _sendTwinApproved,
+                child: const Text('승인하고 보내기'),
+              ),
+            ],
+          ),
+        ],
       ),
     );
   }
@@ -306,17 +330,23 @@ class _ChatScreenState extends State<ChatScreen> {
     final session = context.watch<SessionState>();
     final me = session.user?.id;
 
+    final theme = Theme.of(context);
     return Scaffold(
       appBar: AppBar(
         title: Text(widget.title ?? '대화방 #${widget.conversationId}'),
         actions: [
-          TextButton(onPressed: _busy ? null : _veto, child: const Text('거부권')),
+          IconButton(
+            tooltip: '거부권 (분신 자동응대 중단)',
+            onPressed: _busy ? null : _veto,
+            icon: const Icon(Icons.block),
+          ),
         ],
       ),
       body: Column(
         children: [
           if (_banner != null)
             MaterialBanner(
+              leading: Icon(Icons.info_outline, color: theme.colorScheme.onSurfaceVariant),
               content: Text(_banner!),
               actions: [
                 TextButton(onPressed: () => setState(() => _banner = null), child: const Text('닫기')),
@@ -325,35 +355,40 @@ class _ChatScreenState extends State<ChatScreen> {
           Expanded(
             child: _loadingHistory
                 ? const Center(child: CircularProgressIndicator())
-                : ListView.builder(
-                    controller: _scroll,
-                    padding: const EdgeInsets.symmetric(vertical: 8),
-                    itemCount: _messages.length,
-                    itemBuilder: (context, i) {
-                      final m = _messages[i];
-                      return MessageBubble(
-                        message: m,
-                        isMine: me != null && m.senderId == me,
-                        onRetract: m.isTwin ? () => _retract(m) : null,
-                      );
-                    },
-                  ),
+                : _messages.isEmpty
+                    ? Center(
+                        child: Text(
+                          '아직 메시지가 없습니다. 첫 메시지를 보내 보세요.',
+                          style: theme.textTheme.bodyMedium?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+                        ),
+                      )
+                    : ListView.builder(
+                        controller: _scroll,
+                        padding: const EdgeInsets.symmetric(vertical: 8),
+                        itemCount: _messages.length,
+                        itemBuilder: (context, i) {
+                          final m = _messages[i];
+                          return MessageBubble(
+                            message: m,
+                            isMine: me != null && m.senderId == me,
+                            onRetract: m.isTwin ? () => _retract(m) : null,
+                          );
+                        },
+                      ),
           ),
           _buildL1Panel(context),
           SafeArea(
             child: Padding(
               padding: const EdgeInsets.fromLTRB(12, 8, 12, 12),
               child: Row(
+                crossAxisAlignment: CrossAxisAlignment.end,
                 children: [
                   Expanded(
                     child: TextField(
                       controller: _input,
                       minLines: 1,
                       maxLines: 4,
-                      decoration: const InputDecoration(
-                        hintText: '메시지',
-                        border: OutlineInputBorder(),
-                      ),
+                      decoration: const InputDecoration(hintText: '메시지'),
                     ),
                   ),
                   const SizedBox(width: 8),
diff --git a/mobile/lib/screens/contacts_screen.dart b/mobile/lib/screens/contacts_screen.dart
index ec86ac3..7bc5ffc 100644
--- a/mobile/lib/screens/contacts_screen.dart
+++ b/mobile/lib/screens/contacts_screen.dart
@@ -54,7 +54,7 @@ class _ContactsScreenState extends State<ContactsScreen> {
           children: [
             TextField(
               controller: nameCtrl,
-              decoration: const InputDecoration(labelText: '표시 이름', border: OutlineInputBorder()),
+              decoration: const InputDecoration(labelText: '표시 이름'),
             ),
             const SizedBox(height: 12),
             TextField(
@@ -63,13 +63,12 @@ class _ContactsScreenState extends State<ContactsScreen> {
               decoration: const InputDecoration(
                 labelText: '상대 사용자 ID (선택)',
                 helperText: '대화 시작에 필요',
-                border: OutlineInputBorder(),
               ),
             ),
             const SizedBox(height: 12),
             TextField(
               controller: noteCtrl,
-              decoration: const InputDecoration(labelText: '관계 메모 (선택)', border: OutlineInputBorder()),
+              decoration: const InputDecoration(labelText: '관계 메모 (선택)'),
             ),
           ],
         ),
@@ -118,54 +117,102 @@ class _ContactsScreenState extends State<ContactsScreen> {
     }
   }
 
+  Future<void> _delete(Contact c) async {
+    final session = context.read<SessionState>();
+    if (session.user == null) return;
+    final ok = await showDialog<bool>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: const Text('연락처 삭제'),
+        content: Text('${c.displayName}을(를) 삭제할까요?'),
+        actions: [
+          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('취소')),
+          FilledButton.tonal(onPressed: () => Navigator.pop(ctx, true), child: const Text('삭제')),
+        ],
+      ),
+    );
+    if (ok != true) return;
+    await session.api.deleteContact(session.user!.id, c.id);
+    if (!mounted) return;
+    setState(() => _contacts = _contacts.where((x) => x.id != c.id).toList());
+  }
+
   @override
   Widget build(BuildContext context) {
+    final theme = Theme.of(context);
     return Scaffold(
       appBar: AppBar(title: const Text('연락처')),
       floatingActionButton: FloatingActionButton(
         onPressed: _showAddDialog,
+        tooltip: '연락처 추가',
         child: const Icon(Icons.person_add_alt_1),
       ),
       body: RefreshIndicator(
         onRefresh: _load,
         child: _loading
-            ? ListView(children: const [SizedBox(height: 120), Center(child: CircularProgressIndicator())])
+            ? ListView(children: const [SizedBox(height: 160), Center(child: CircularProgressIndicator())])
             : ListView(
+                padding: const EdgeInsets.symmetric(vertical: 4),
                 children: [
                   if (_error != null)
                     Padding(
-                      padding: const EdgeInsets.all(16),
-                      child: Text(_error!, style: TextStyle(color: Theme.of(context).colorScheme.error)),
+                      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+                      child: Text(_error!, style: TextStyle(color: theme.colorScheme.error)),
                     ),
                   if (_contacts.isEmpty)
-                    const Padding(
-                      padding: EdgeInsets.all(24),
-                      child: Text('연락처가 없습니다. + 버튼으로 추가하세요.'),
+                    Padding(
+                      padding: const EdgeInsets.symmetric(vertical: 64, horizontal: 32),
+                      child: Column(
+                        children: [
+                          Icon(Icons.person_add_outlined, size: 40, color: theme.colorScheme.outline),
+                          const SizedBox(height: 12),
+                          Text('연락처가 없습니다', style: theme.textTheme.titleMedium),
+                          const SizedBox(height: 4),
+                          Text(
+                            '오른쪽 아래 버튼으로 첫 연락처를 추가해 보세요.',
+                            textAlign: TextAlign.center,
+                            style: theme.textTheme.bodySmall?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+                          ),
+                        ],
+                      ),
                     ),
                   for (final c in _contacts)
-                    ListTile(
-                      leading: const CircleAvatar(child: Icon(Icons.person_outline)),
-                      title: Text(c.displayName),
-                      subtitle: Text(
-                        [
-                          if (c.contactUserId != null) '사용자 #${c.contactUserId}',
-                          if (c.relationshipNote.isNotEmpty) c.relationshipNote,
-                        ].join(' · '),
+                    Padding(
+                      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
+                      child: ListTile(
+                        leading: CircleAvatar(
+                          backgroundColor: theme.colorScheme.secondaryContainer,
+                          child: Text(
+                            c.displayName.isEmpty ? '?' : c.displayName.substring(0, 1),
+                            style: TextStyle(
+                              color: theme.colorScheme.onSecondaryContainer,
+                              fontWeight: FontWeight.w700,
+                            ),
+                          ),
+                        ),
+                        title: Text(c.displayName, style: theme.textTheme.titleSmall),
+                        subtitle: Text(
+                          [
+                            if (c.contactUserId != null) '사용자 #${c.contactUserId}',
+                            if (c.relationshipNote.isNotEmpty) c.relationshipNote,
+                          ].join(' · '),
+                          style: theme.textTheme.bodySmall,
+                        ),
+                        trailing: Row(
+                          mainAxisSize: MainAxisSize.min,
+                          children: [
+                            if (c.contactUserId != null)
+                              TextButton(onPressed: () => _startChat(c), child: const Text('대화')),
+                            IconButton(
+                              tooltip: '삭제',
+                              icon: const Icon(Icons.delete_outline, size: 20),
+                              onPressed: () => _delete(c),
+                            ),
+                          ],
+                        ),
                       ),
-                      trailing: c.contactUserId == null
-                          ? null
-                          : TextButton(onPressed: () => _startChat(c), child: const Text('대화')),
-                      onLongPress: () async {
-                        final session = context.read<SessionState>();
-                        if (session.user == null) return;
-                        await session.api.deleteContact(session.user!.id, c.id);
-                        setState(() => _contacts = _contacts.where((x) => x.id != c.id).toList());
-                      },
                     ),
-                  const Padding(
-                    padding: EdgeInsets.all(16),
-                    child: Text('길게 누르면 삭제됩니다.', textAlign: TextAlign.center),
-                  ),
+                  const SizedBox(height: 72),
                 ],
               ),
       ),
diff --git a/mobile/lib/screens/conversation_list_screen.dart b/mobile/lib/screens/conversation_list_screen.dart
index 2003b4e..7430603 100644
--- a/mobile/lib/screens/conversation_list_screen.dart
+++ b/mobile/lib/screens/conversation_list_screen.dart
@@ -58,7 +58,6 @@ class _ConversationListScreenState extends State<ConversationListScreen> {
           decoration: const InputDecoration(
             labelText: '상대 사용자 ID',
             helperText: '연락처에 등록된 상대면 연락처 화면에서 시작하는 편이 낫습니다.',
-            border: OutlineInputBorder(),
           ),
         ),
         actions: [
@@ -84,14 +83,27 @@ class _ConversationListScreenState extends State<ConversationListScreen> {
     }
   }
 
+  Color _avatarColor(BuildContext context, int seed) {
+    final scheme = Theme.of(context).colorScheme;
+    final palette = [scheme.primaryContainer, scheme.tertiaryContainer, scheme.secondaryContainer];
+    return palette[seed % palette.length];
+  }
+
+  Color _onAvatarColor(BuildContext context, int seed) {
+    final scheme = Theme.of(context).colorScheme;
+    final palette = [scheme.onPrimaryContainer, scheme.onTertiaryContainer, scheme.onSecondaryContainer];
+    return palette[seed % palette.length];
+  }
+
   @override
   Widget build(BuildContext context) {
     final session = context.watch<SessionState>();
+    final theme = Theme.of(context);
     final me = session.user?.id;
 
     return Scaffold(
       appBar: AppBar(
-        title: Text('분신 · ${session.user?.displayName ?? ''}'),
+        title: const Text('분신'),
         actions: [
           IconButton(
             tooltip: '사후 알림',
@@ -108,68 +120,120 @@ class _ConversationListScreenState extends State<ConversationListScreen> {
             },
             icon: const Icon(Icons.contacts_outlined),
           ),
-          IconButton(
-            tooltip: '말투 샘플',
-            onPressed: () {
-              Navigator.of(context).push(MaterialPageRoute(builder: (_) => const OnboardingToneScreen()));
-            },
-            icon: const Icon(Icons.record_voice_over_outlined),
-          ),
-          IconButton(
-            tooltip: '자율성 설정',
-            onPressed: () {
-              Navigator.of(context).push(
-                MaterialPageRoute(builder: (_) => const AutonomySettingsScreen()),
-              );
-            },
-            icon: const Icon(Icons.tune),
+          PopupMenuButton<VoidCallback>(
+            tooltip: '더보기',
+            icon: const Icon(Icons.more_vert),
+            onSelected: (action) => action(),
+            itemBuilder: (context) => [
+              PopupMenuItem(
+                value: () => Navigator.of(context)
+                    .push(MaterialPageRoute(builder: (_) => const OnboardingToneScreen())),
+                child: const ListTile(
+                  contentPadding: EdgeInsets.zero,
+                  leading: Icon(Icons.record_voice_over_outlined),
+                  title: Text('말투 샘플'),
+                ),
+              ),
+              PopupMenuItem(
+                value: () => Navigator.of(context)
+                    .push(MaterialPageRoute(builder: (_) => const AutonomySettingsScreen())),
+                child: const ListTile(
+                  contentPadding: EdgeInsets.zero,
+                  leading: Icon(Icons.tune),
+                  title: Text('자율성 설정'),
+                ),
+              ),
+            ],
           ),
+          const SizedBox(width: 4),
         ],
       ),
-      floatingActionButton: FloatingActionButton(
+      floatingActionButton: FloatingActionButton.extended(
         onPressed: _createConversation,
-        child: const Icon(Icons.chat),
+        icon: const Icon(Icons.chat),
+        label: const Text('새 대화'),
       ),
       body: RefreshIndicator(
         onRefresh: _load,
         child: _loading
-            ? ListView(children: const [SizedBox(height: 120), Center(child: CircularProgressIndicator())])
+            ? ListView(children: const [SizedBox(height: 160), Center(child: CircularProgressIndicator())])
             : ListView(
+                padding: const EdgeInsets.symmetric(vertical: 4),
                 children: [
+                  Padding(
+                    padding: const EdgeInsets.fromLTRB(16, 4, 16, 12),
+                    child: Text(
+                      session.user == null ? '' : '안녕하세요, ${session.user!.displayName}님',
+                      style: theme.textTheme.bodyMedium?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+                    ),
+                  ),
                   if (_error != null)
                     Padding(
-                      padding: const EdgeInsets.all(16),
-                      child: Text(_error!, style: TextStyle(color: Theme.of(context).colorScheme.error)),
+                      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+                      child: Text(_error!, style: TextStyle(color: theme.colorScheme.error)),
                     ),
                   if (_rooms.isEmpty)
-                    const Padding(
-                      padding: EdgeInsets.all(24),
-                      child: Text('대화방이 없습니다. + 버튼이나 연락처에서 대화를 시작하세요.'),
+                    Padding(
+                      padding: const EdgeInsets.symmetric(vertical: 64, horizontal: 32),
+                      child: Column(
+                        children: [
+                          Icon(Icons.chat_bubble_outline, size: 40, color: theme.colorScheme.outline),
+                          const SizedBox(height: 12),
+                          Text(
+                            '대화방이 없습니다',
+                            style: theme.textTheme.titleMedium,
+                          ),
+                          const SizedBox(height: 4),
+                          Text(
+                            '연락처나 "새 대화" 버튼으로 첫 대화를 시작해 보세요.',
+                            textAlign: TextAlign.center,
+                            style: theme.textTheme.bodySmall?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+                          ),
+                        ],
+                      ),
                     ),
                   for (final room in _rooms)
-                    ListTile(
-                      leading: CircleAvatar(
-                        child: Icon(room.isGroup ? Icons.groups_outlined : Icons.chat_bubble_outline),
-                      ),
-                      title: Text(me == null ? '대화방 #${room.id}' : room.titleFor(me)),
-                      subtitle: Text(
-                        [
-                          'ID ${room.id}',
-                          if (room.twinDisabledByPeer) '상대가 분신 거부',
-                        ].join(' · '),
-                      ),
-                      onTap: () async {
-                        await Navigator.of(context).push(
-                          MaterialPageRoute(
-                            builder: (_) => ChatScreen(
-                              conversationId: room.id,
-                              title: me == null ? null : room.titleFor(me),
-                            ),
+                    Padding(
+                      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
+                      child: ListTile(
+                        leading: CircleAvatar(
+                          backgroundColor: _avatarColor(context, room.id),
+                          child: Icon(
+                            room.isGroup ? Icons.groups_outlined : Icons.person_outline,
+                            color: _onAvatarColor(context, room.id),
                           ),
-                        );
-                        await _load();
-                      },
+                        ),
+                        title: Text(
+                          me == null ? '대화방 #${room.id}' : room.titleFor(me),
+                          style: theme.textTheme.titleSmall,
+                        ),
+                        subtitle: room.twinDisabledByPeer
+                            ? Row(
+                                children: [
+                                  Icon(Icons.block, size: 13, color: theme.colorScheme.error),
+                                  const SizedBox(width: 4),
+                                  Text(
+                                    '상대가 분신을 거부함',
+                                    style: theme.textTheme.bodySmall?.copyWith(color: theme.colorScheme.error),
+                                  ),
+                                ],
+                              )
+                            : Text('대화방 ID ${room.id}', style: theme.textTheme.bodySmall),
+                        trailing: const Icon(Icons.chevron_right, size: 20),
+                        onTap: () async {
+                          await Navigator.of(context).push(
+                            MaterialPageRoute(
+                              builder: (_) => ChatScreen(
+                                conversationId: room.id,
+                                title: me == null ? null : room.titleFor(me),
+                              ),
+                            ),
+                          );
+                          await _load();
+                        },
+                      ),
                     ),
+                  const SizedBox(height: 72),
                 ],
               ),
       ),
diff --git a/mobile/lib/screens/data_flow_screen.dart b/mobile/lib/screens/data_flow_screen.dart
index f8b4fa2..a07c1ed 100644
--- a/mobile/lib/screens/data_flow_screen.dart
+++ b/mobile/lib/screens/data_flow_screen.dart
@@ -7,6 +7,50 @@ import '../state/session_state.dart';
 class DataFlowScreen extends StatelessWidget {
   const DataFlowScreen({super.key});
 
+  Widget _section(
+    BuildContext context, {
+    required IconData icon,
+    required Color tint,
+    required String title,
+    required String body,
+  }) {
+    final theme = Theme.of(context);
+    return Container(
+      margin: const EdgeInsets.only(bottom: 16),
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: theme.colorScheme.surfaceContainerHigh,
+        borderRadius: BorderRadius.circular(16),
+      ),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Container(
+            width: 36,
+            height: 36,
+            alignment: Alignment.center,
+            decoration: BoxDecoration(color: tint.withOpacity(0.15), shape: BoxShape.circle),
+            child: Icon(icon, size: 18, color: tint),
+          ),
+          const SizedBox(width: 12),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(title, style: theme.textTheme.titleSmall),
+                const SizedBox(height: 4),
+                Text(
+                  body,
+                  style: theme.textTheme.bodyMedium?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+                ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     final session = context.watch<SessionState>();
@@ -16,18 +60,20 @@ class DataFlowScreen extends StatelessWidget {
     return Scaffold(
       appBar: AppBar(title: const Text('데이터 흐름')),
       body: ListView(
-        padding: const EdgeInsets.all(20),
+        padding: const EdgeInsets.all(16),
         children: [
-          Text('기기 안에만 둡니다', style: theme.textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w700)),
-          const SizedBox(height: 8),
-          Text(
-            '말투 샘플·온보딩 입력은 이 기기의 로컬 저장소에만 보관합니다. '
-            '원문 대화 전체를 서버로 올리지 않는 것이 기본 원칙입니다.',
-            style: theme.textTheme.bodyMedium?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+          _section(
+            context,
+            icon: Icons.lock_outline,
+            tint: Colors.green.shade600,
+            title: '기기 안에만 둡니다',
+            body: '말투 샘플·온보딩 입력은 이 기기의 로컬 저장소에만 보관합니다. '
+                '원문 대화 전체를 서버로 올리지 않는 것이 기본 원칙입니다.',
           ),
-          const SizedBox(height: 12),
           Card(
+            margin: const EdgeInsets.only(bottom: 16),
             child: ListTile(
+              leading: Icon(Icons.record_voice_over_outlined, color: theme.colorScheme.primary),
               title: Text('말투 샘플 ${samples.length}개'),
               subtitle: Text(
                 [
@@ -40,23 +86,23 @@ class DataFlowScreen extends StatelessWidget {
               isThreeLine: true,
             ),
           ),
-          const SizedBox(height: 24),
-          Text('서버로 보낼 수 있는 것', style: theme.textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w700)),
-          const SizedBox(height: 8),
-          Text(
-            '초안이 필요할 때: 최근 대화 몇 줄 + 말투 샘플 일부(최소 컨텍스트).\n'
-            '채팅 릴레이: 보낸 메시지 본문.\n'
-            '계정: 표시 이름·초대 코드·세션 토큰.\n'
-            '푸시(준비 중): 디바이스 토큰만 등록, 실제 전송은 FCM 프로젝트 연결 후.',
-            style: theme.textTheme.bodyMedium?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+          _section(
+            context,
+            icon: Icons.cloud_upload_outlined,
+            tint: Colors.amber.shade800,
+            title: '서버로 보낼 수 있는 것',
+            body: '초안이 필요할 때: 최근 대화 몇 줄 + 말투 샘플 일부(최소 컨텍스트)\n'
+                '채팅 릴레이: 보낸 메시지 본문\n'
+                '계정: 표시 이름·초대 코드·세션 토큰\n'
+                '푸시(준비 중): 디바이스 토큰만 등록, 실제 전송은 FCM 프로젝트 연결 후',
           ),
-          const SizedBox(height: 24),
-          Text('보내지 않는 것', style: theme.textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w700)),
-          const SizedBox(height: 8),
-          Text(
-            '전체 채팅 백업 업로드, 온디바이스 말투 학습 원문 코퍼스, '
-            '관계 메모의 자동 클라우드 분석.',
-            style: theme.textTheme.bodyMedium?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+          _section(
+            context,
+            icon: Icons.block,
+            tint: theme.colorScheme.error,
+            title: '보내지 않는 것',
+            body: '전체 채팅 백업 업로드, 온디바이스 말투 학습 원문 코퍼스, '
+                '관계 메모의 자동 클라우드 분석',
           ),
         ],
       ),
diff --git a/mobile/lib/screens/inbox_screen.dart b/mobile/lib/screens/inbox_screen.dart
index 7c1e34c..45f24cc 100644
--- a/mobile/lib/screens/inbox_screen.dart
+++ b/mobile/lib/screens/inbox_screen.dart
@@ -51,11 +51,12 @@ class _InboxScreenState extends State<InboxScreen> {
       body: RefreshIndicator(
         onRefresh: _load,
         child: _loading
-            ? ListView(children: const [SizedBox(height: 120), Center(child: CircularProgressIndicator())])
+            ? ListView(children: const [SizedBox(height: 160), Center(child: CircularProgressIndicator())])
             : ListView(
+                padding: const EdgeInsets.fromLTRB(12, 12, 12, 24),
                 children: [
                   Padding(
-                    padding: const EdgeInsets.fromLTRB(16, 16, 16, 8),
+                    padding: const EdgeInsets.fromLTRB(4, 0, 4, 12),
                     child: Text(
                       '분신이 보류·차단한 내용과 에스컬레이션 기록입니다. '
                       '이미 보낸 분신 메시지는 해당 대화방에서 되돌릴 수 있습니다.',
@@ -64,36 +65,89 @@ class _InboxScreenState extends State<InboxScreen> {
                   ),
                   if (_error != null)
                     Padding(
-                      padding: const EdgeInsets.all(16),
+                      padding: const EdgeInsets.symmetric(horizontal: 4, vertical: 8),
                       child: Text(_error!, style: TextStyle(color: theme.colorScheme.error)),
                     ),
                   if (_logs.isEmpty)
-                    const Padding(
-                      padding: EdgeInsets.all(24),
-                      child: Text('새 알림이 없습니다.'),
+                    Padding(
+                      padding: const EdgeInsets.symmetric(vertical: 64, horizontal: 32),
+                      child: Column(
+                        children: [
+                          Icon(Icons.notifications_none, size: 40, color: theme.colorScheme.outline),
+                          const SizedBox(height: 12),
+                          Text('새 알림이 없습니다', style: theme.textTheme.titleMedium),
+                        ],
+                      ),
                     ),
                   for (final log in _logs)
-                    ListTile(
-                      leading: Icon(
-                        log.resolved ? Icons.check_circle_outline : Icons.warning_amber_rounded,
-                        color: log.resolved ? theme.colorScheme.primary : theme.colorScheme.error,
-                      ),
-                      title: Text(log.reason.isEmpty ? '에스컬레이션' : log.reason),
-                      subtitle: Text(
-                        [
-                          '대화방 #${log.conversationId}',
-                          if (log.messageSnippet.isNotEmpty) log.messageSnippet,
-                          log.createdAt.toLocal().toString().split('.').first,
-                        ].join('\n'),
-                      ),
-                      isThreeLine: true,
-                      onTap: () {
-                        Navigator.of(context).push(
-                          MaterialPageRoute(
-                            builder: (_) => ChatScreen(conversationId: log.conversationId),
+                    Padding(
+                      padding: const EdgeInsets.only(bottom: 8),
+                      child: Card(
+                        child: InkWell(
+                          borderRadius: BorderRadius.circular(16),
+                          onTap: () {
+                            Navigator.of(context).push(
+                              MaterialPageRoute(
+                                builder: (_) => ChatScreen(conversationId: log.conversationId),
+                              ),
+                            );
+                          },
+                          child: Padding(
+                            padding: const EdgeInsets.all(14),
+                            child: Row(
+                              crossAxisAlignment: CrossAxisAlignment.start,
+                              children: [
+                                CircleAvatar(
+                                  radius: 18,
+                                  backgroundColor: log.resolved
+                                      ? theme.colorScheme.primaryContainer
+                                      : theme.colorScheme.errorContainer,
+                                  child: Icon(
+                                    log.resolved ? Icons.check_circle_outline : Icons.warning_amber_rounded,
+                                    size: 18,
+                                    color: log.resolved
+                                        ? theme.colorScheme.onPrimaryContainer
+                                        : theme.colorScheme.onErrorContainer,
+                                  ),
+                                ),
+                                const SizedBox(width: 12),
+                                Expanded(
+                                  child: Column(
+                                    crossAxisAlignment: CrossAxisAlignment.start,
+                                    children: [
+                                      Text(
+                                        log.reason.isEmpty ? '에스컬레이션' : log.reason,
+                                        style: theme.textTheme.titleSmall,
+                                      ),
+                                      const SizedBox(height: 2),
+                                      Text(
+                                        '대화방 #${log.conversationId}',
+                                        style: theme.textTheme.bodySmall
+                                            ?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+                                      ),
+                                      if (log.messageSnippet.isNotEmpty) ...[
+                                        const SizedBox(height: 6),
+                                        Text(
+                                          log.messageSnippet,
+                                          maxLines: 2,
+                                          overflow: TextOverflow.ellipsis,
+                                          style: theme.textTheme.bodyMedium,
+                                        ),
+                                      ],
+                                      const SizedBox(height: 6),
+                                      Text(
+                                        log.createdAt.toLocal().toString().split('.').first,
+                                        style: theme.textTheme.labelSmall
+                                            ?.copyWith(color: theme.colorScheme.outline),
+                                      ),
+                                    ],
+                                  ),
+                                ),
+                              ],
+                            ),
                           ),
-                        );
-                      },
+                        ),
+                      ),
                     ),
                 ],
               ),
diff --git a/mobile/lib/screens/onboarding_tone_screen.dart b/mobile/lib/screens/onboarding_tone_screen.dart
index 6983f10..3d7776e 100644
--- a/mobile/lib/screens/onboarding_tone_screen.dart
+++ b/mobile/lib/screens/onboarding_tone_screen.dart
@@ -46,6 +46,7 @@ class _OnboardingToneScreenState extends State<OnboardingToneScreen> {
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
+    final scheme = theme.colorScheme;
     return Scaffold(
       appBar: AppBar(
         title: const Text('말투 샘플'),
@@ -54,20 +55,28 @@ class _OnboardingToneScreenState extends State<OnboardingToneScreen> {
             onPressed: () => context.read<SessionState>().skipToneOnboarding(),
             child: const Text('나중에'),
           ),
+          const SizedBox(width: 8),
         ],
       ),
       body: SafeArea(
         child: ListView(
           padding: const EdgeInsets.all(24),
           children: [
-            Text('분신이 따라 쓸 말투', style: theme.textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.w700)),
+            Container(
+              width: 56,
+              height: 56,
+              decoration: BoxDecoration(color: scheme.primaryContainer, borderRadius: BorderRadius.circular(16)),
+              child: Icon(Icons.record_voice_over_outlined, size: 28, color: scheme.onPrimaryContainer),
+            ),
+            const SizedBox(height: 16),
+            Text('분신이 따라 쓸 말투', style: theme.textTheme.headlineSmall),
             const SizedBox(height: 8),
             Text(
               '자주 쓰는 짧은 문장을 3~4개 적어 주세요. 기기에만 저장되며, 초안 요청 시 참고로 씁니다. '
               '최종 문구·수집 방식은 사람 PoC 이후에 다듬습니다.',
-              style: theme.textTheme.bodyMedium?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+              style: theme.textTheme.bodyMedium?.copyWith(color: scheme.onSurfaceVariant),
             ),
-            const SizedBox(height: 24),
+            const SizedBox(height: 28),
             for (var i = 0; i < _samples.length; i++) ...[
               TextField(
                 controller: _samples[i],
@@ -75,12 +84,26 @@ class _OnboardingToneScreenState extends State<OnboardingToneScreen> {
                 decoration: InputDecoration(
                   labelText: '샘플 ${i + 1}',
                   hintText: i == 0 ? '예: ㅇㅇ 알겠음' : null,
-                  border: const OutlineInputBorder(),
+                  prefixIcon: Padding(
+                    padding: const EdgeInsets.only(left: 4, right: 4, top: 4),
+                    child: CircleAvatar(
+                      radius: 12,
+                      backgroundColor: scheme.secondaryContainer,
+                      child: Text(
+                        '${i + 1}',
+                        style: TextStyle(
+                          fontSize: 12,
+                          fontWeight: FontWeight.w700,
+                          color: scheme.onSecondaryContainer,
+                        ),
+                      ),
+                    ),
+                  ),
                 ),
               ),
               const SizedBox(height: 12),
             ],
-            const SizedBox(height: 8),
+            const SizedBox(height: 12),
             FilledButton(
               onPressed: () => _save(markDone: true),
               child: const Text('저장하고 시작'),
diff --git a/mobile/lib/screens/sessions_screen.dart b/mobile/lib/screens/sessions_screen.dart
index 097a1b0..64355fe 100644
--- a/mobile/lib/screens/sessions_screen.dart
+++ b/mobile/lib/screens/sessions_screen.dart
@@ -72,32 +72,53 @@ class _SessionsScreenState extends State<SessionsScreen> {
 
   @override
   Widget build(BuildContext context) {
+    final theme = Theme.of(context);
     return Scaffold(
       appBar: AppBar(title: const Text('로그인 세션')),
       body: RefreshIndicator(
         onRefresh: _load,
         child: _loading
-            ? ListView(children: const [SizedBox(height: 120), Center(child: CircularProgressIndicator())])
+            ? ListView(children: const [SizedBox(height: 160), Center(child: CircularProgressIndicator())])
             : ListView(
+                padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 8),
                 children: [
-                  const Padding(
-                    padding: EdgeInsets.all(16),
-                    child: Text('이 계정에 연결된 활성 세션입니다. 다른 기기를 종료하면 해당 토큰이 즉시 무효화됩니다.'),
+                  Padding(
+                    padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 8),
+                    child: Text(
+                      '이 계정에 연결된 활성 세션입니다. 다른 기기를 종료하면 해당 토큰이 즉시 무효화됩니다.',
+                      style: theme.textTheme.bodyMedium?.copyWith(color: theme.colorScheme.onSurfaceVariant),
+                    ),
                   ),
                   if (_error != null)
                     Padding(
-                      padding: const EdgeInsets.all(16),
-                      child: Text(_error!, style: TextStyle(color: Theme.of(context).colorScheme.error)),
+                      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 8),
+                      child: Text(_error!, style: TextStyle(color: theme.colorScheme.error)),
                     ),
                   for (final s in _sessions)
-                    ListTile(
-                      leading: Icon(s['is_current'] == true ? Icons.smartphone : Icons.devices_other),
-                      title: Text(s['is_current'] == true ? '이 기기 (현재)' : '세션 #${s['id']}'),
-                      subtitle: Text('만료: ${s['expires_at'] ?? ''}'),
-                      trailing: IconButton(
-                        tooltip: '세션 종료',
-                        icon: const Icon(Icons.logout),
-                        onPressed: () => _revoke(s),
+                    Padding(
+                      padding: const EdgeInsets.symmetric(vertical: 2),
+                      child: ListTile(
+                        leading: CircleAvatar(
+                          backgroundColor: s['is_current'] == true
+                              ? theme.colorScheme.primaryContainer
+                              : theme.colorScheme.surfaceContainerHighest,
+                          child: Icon(
+                            s['is_current'] == true ? Icons.smartphone : Icons.devices_other,
+                            color: s['is_current'] == true
+                                ? theme.colorScheme.onPrimaryContainer
+                                : theme.colorScheme.onSurfaceVariant,
+                          ),
+                        ),
+                        title: Text(
+                          s['is_current'] == true ? '이 기기 (현재)' : '세션 #${s['id']}',
+                          style: theme.textTheme.titleSmall,
+                        ),
+                        subtitle: Text('만료: ${s['expires_at'] ?? ''}', style: theme.textTheme.bodySmall),
+                        trailing: IconButton(
+                          tooltip: '세션 종료',
+                          icon: const Icon(Icons.logout),
+                          onPressed: () => _revoke(s),
+                        ),
                       ),
                     ),
                 ],
diff --git a/mobile/lib/screens/signup_screen.dart b/mobile/lib/screens/signup_screen.dart
index 89652a9..173f747 100644
--- a/mobile/lib/screens/signup_screen.dart
+++ b/mobile/lib/screens/signup_screen.dart
@@ -24,28 +24,47 @@ class _SignupScreenState extends State<SignupScreen> {
   @override
   Widget build(BuildContext context) {
     final session = context.watch<SessionState>();
+    final theme = Theme.of(context);
+    final scheme = theme.colorScheme;
     return Scaffold(
       body: SafeArea(
         child: Padding(
-          padding: const EdgeInsets.all(24),
+          padding: const EdgeInsets.symmetric(horizontal: 24),
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.stretch,
             children: [
-              const SizedBox(height: 48),
-              Text('분신', style: Theme.of(context).textTheme.displaySmall?.copyWith(fontWeight: FontWeight.w800)),
+              const Spacer(flex: 3),
+              Center(
+                child: Container(
+                  width: 72,
+                  height: 72,
+                  decoration: BoxDecoration(
+                    color: scheme.primaryContainer,
+                    borderRadius: BorderRadius.circular(22),
+                  ),
+                  child: Icon(Icons.auto_awesome, size: 34, color: scheme.onPrimaryContainer),
+                ),
+              ),
+              const SizedBox(height: 20),
+              Text(
+                '분신',
+                textAlign: TextAlign.center,
+                style: theme.textTheme.displaySmall?.copyWith(fontWeight: FontWeight.w800),
+              ),
               const SizedBox(height: 8),
               Text(
-                '초대 코드로 클로즈드 베타에 참여합니다.',
-                style: Theme.of(context).textTheme.bodyLarge?.copyWith(
-                      color: Theme.of(context).colorScheme.onSurfaceVariant,
-                    ),
+                '나를 대신해 답하는, 나만의 분신',
+                textAlign: TextAlign.center,
+                style: theme.textTheme.bodyLarge?.copyWith(color: scheme.onSurfaceVariant),
               ),
-              const SizedBox(height: 32),
+              const Spacer(flex: 3),
+              Text('초대 코드로 클로즈드 베타에 참여합니다', style: theme.textTheme.labelLarge),
+              const SizedBox(height: 12),
               TextField(
                 controller: _invite,
                 decoration: const InputDecoration(
                   labelText: '초대 코드',
-                  border: OutlineInputBorder(),
+                  prefixIcon: Icon(Icons.vpn_key),
                 ),
                 textInputAction: TextInputAction.next,
               ),
@@ -54,15 +73,15 @@ class _SignupScreenState extends State<SignupScreen> {
                 controller: _name,
                 decoration: const InputDecoration(
                   labelText: '표시 이름',
-                  border: OutlineInputBorder(),
+                  prefixIcon: Icon(Icons.person_outline),
                 ),
                 textInputAction: TextInputAction.done,
               ),
               if (session.error != null) ...[
                 const SizedBox(height: 12),
-                Text(session.error!, style: TextStyle(color: Theme.of(context).colorScheme.error)),
+                Text(session.error!, style: TextStyle(color: scheme.error)),
               ],
-              const Spacer(),
+              const SizedBox(height: 20),
               FilledButton(
                 onPressed: session.loading
                     ? null
@@ -71,6 +90,7 @@ class _SignupScreenState extends State<SignupScreen> {
                     ? const SizedBox(height: 20, width: 20, child: CircularProgressIndicator(strokeWidth: 2))
                     : const Text('시작하기'),
               ),
+              const SizedBox(height: 32),
             ],
           ),
         ),
diff --git a/mobile/lib/theme/app_theme.dart b/mobile/lib/theme/app_theme.dart
new file mode 100644
index 0000000..d185243
--- /dev/null
+++ b/mobile/lib/theme/app_theme.dart
@@ -0,0 +1,149 @@
+import 'package:flutter/material.dart';
+
+/// Central design tokens for 분신 (Bunsin). One seed color drives the whole
+/// Material 3 palette; `twinAccent` is a separate warm accent used only for
+/// the AI-authored badge/border so a twin-written bubble never reads as
+/// something the human actually typed (PRD §3.1 분신 뱃지).
+class AppTheme {
+  AppTheme._();
+
+  static const _seed = Color(0xFF1F6F5B);
+
+  static Color twinAccent(Brightness brightness) =>
+      brightness == Brightness.dark ? Colors.amber.shade300 : Colors.amber.shade800;
+
+  static ThemeData light() => _build(Brightness.light);
+  static ThemeData dark() => _build(Brightness.dark);
+
+  static ThemeData _build(Brightness brightness) {
+    final scheme = ColorScheme.fromSeed(seedColor: _seed, brightness: brightness);
+
+    return ThemeData(
+      useMaterial3: true,
+      brightness: brightness,
+      colorScheme: scheme,
+      scaffoldBackgroundColor: scheme.surface,
+      visualDensity: VisualDensity.comfortable,
+      textTheme: _textTheme(),
+      appBarTheme: AppBarTheme(
+        backgroundColor: scheme.surface,
+        foregroundColor: scheme.onSurface,
+        surfaceTintColor: scheme.surfaceTint,
+        elevation: 0,
+        scrolledUnderElevation: 1,
+        centerTitle: false,
+        titleTextStyle: TextStyle(
+          fontSize: 20,
+          fontWeight: FontWeight.w800,
+          color: scheme.onSurface,
+          letterSpacing: -0.2,
+        ),
+      ),
+      cardTheme: CardThemeData(
+        elevation: 0,
+        color: scheme.surfaceContainerHigh,
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
+        margin: EdgeInsets.zero,
+      ),
+      listTileTheme: ListTileThemeData(
+        iconColor: scheme.onSurfaceVariant,
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(14)),
+        contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
+      ),
+      dividerTheme: DividerThemeData(color: scheme.outlineVariant, space: 32, thickness: 1),
+      inputDecorationTheme: InputDecorationTheme(
+        filled: true,
+        fillColor: scheme.surfaceContainerHighest,
+        contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
+        border: OutlineInputBorder(
+          borderRadius: BorderRadius.circular(14),
+          borderSide: BorderSide.none,
+        ),
+        enabledBorder: OutlineInputBorder(
+          borderRadius: BorderRadius.circular(14),
+          borderSide: BorderSide.none,
+        ),
+        focusedBorder: OutlineInputBorder(
+          borderRadius: BorderRadius.circular(14),
+          borderSide: BorderSide(color: scheme.primary, width: 1.6),
+        ),
+        errorBorder: OutlineInputBorder(
+          borderRadius: BorderRadius.circular(14),
+          borderSide: BorderSide(color: scheme.error, width: 1.2),
+        ),
+        focusedErrorBorder: OutlineInputBorder(
+          borderRadius: BorderRadius.circular(14),
+          borderSide: BorderSide(color: scheme.error, width: 1.6),
+        ),
+        hintStyle: TextStyle(color: scheme.onSurfaceVariant.withOpacity(0.7)),
+      ),
+      filledButtonTheme: FilledButtonThemeData(
+        style: FilledButton.styleFrom(
+          padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 14),
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(14)),
+          textStyle: const TextStyle(fontWeight: FontWeight.w700),
+        ),
+      ),
+      outlinedButtonTheme: OutlinedButtonThemeData(
+        style: OutlinedButton.styleFrom(
+          padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 14),
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(14)),
+        ),
+      ),
+      textButtonTheme: TextButtonThemeData(
+        style: TextButton.styleFrom(
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
+        ),
+      ),
+      iconButtonTheme: IconButtonThemeData(
+        style: IconButton.styleFrom(
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+        ),
+      ),
+      segmentedButtonTheme: SegmentedButtonThemeData(
+        style: SegmentedButton.styleFrom(
+          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
+        ),
+      ),
+      chipTheme: ChipThemeData(
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
+        side: BorderSide.none,
+        backgroundColor: scheme.surfaceContainerHighest,
+        labelStyle: TextStyle(color: scheme.onSurfaceVariant, fontWeight: FontWeight.w600, fontSize: 12),
+        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
+      ),
+      floatingActionButtonTheme: FloatingActionButtonThemeData(
+        backgroundColor: scheme.primary,
+        foregroundColor: scheme.onPrimary,
+        elevation: 1,
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(18)),
+      ),
+      snackBarTheme: SnackBarThemeData(
+        behavior: SnackBarBehavior.floating,
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+      ),
+      bannerTheme: MaterialBannerThemeData(
+        backgroundColor: scheme.surfaceContainerHigh,
+        padding: const EdgeInsets.all(16),
+      ),
+      dialogTheme: DialogThemeData(
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
+      ),
+      progressIndicatorTheme: ProgressIndicatorThemeData(color: scheme.primary),
+    );
+  }
+
+  static TextTheme _textTheme() {
+    return const TextTheme(
+      displaySmall: TextStyle(fontWeight: FontWeight.w800, letterSpacing: -0.5),
+      headlineSmall: TextStyle(fontWeight: FontWeight.w800, letterSpacing: -0.3),
+      titleLarge: TextStyle(fontWeight: FontWeight.w700),
+      titleMedium: TextStyle(fontWeight: FontWeight.w700),
+      titleSmall: TextStyle(fontWeight: FontWeight.w700),
+      bodyLarge: TextStyle(height: 1.4),
+      bodyMedium: TextStyle(height: 1.4),
+      labelLarge: TextStyle(fontWeight: FontWeight.w700),
+    );
+  }
+}
diff --git a/mobile/lib/widgets/message_bubble.dart b/mobile/lib/widgets/message_bubble.dart
index 4d79980..3b73031 100644
--- a/mobile/lib/widgets/message_bubble.dart
+++ b/mobile/lib/widgets/message_bubble.dart
@@ -1,8 +1,10 @@
 import 'package:flutter/material.dart';
 
 import '../models/models.dart';
+import '../theme/app_theme.dart';
 
-/// Twin messages use a dashed border + badge (PRD §3.1 분신 뱃지).
+/// Twin messages get a dashed border + badge (PRD §3.1 분신 뱃지) so an
+/// auto-sent bubble never reads as something the human actually typed.
 class MessageBubble extends StatelessWidget {
   const MessageBubble({
     super.key,
@@ -15,90 +17,146 @@ class MessageBubble extends StatelessWidget {
   final bool isMine;
   final VoidCallback? onRetract;
 
+  static String _time(DateTime dt) {
+    final local = dt.toLocal();
+    final h = local.hour.toString().padLeft(2, '0');
+    final m = local.minute.toString().padLeft(2, '0');
+    return '$h:$m';
+  }
+
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
+    final scheme = theme.colorScheme;
     final twin = message.isTwin;
-    final bg = isMine
-        ? theme.colorScheme.primaryContainer
-        : theme.colorScheme.surfaceContainerHighest;
+    final retracted = message.retracted;
+    final accent = AppTheme.twinAccent(theme.brightness);
+
+    final Color bg;
+    final Color fg;
+    if (retracted) {
+      bg = scheme.surfaceContainerHigh;
+      fg = scheme.onSurfaceVariant;
+    } else if (isMine) {
+      bg = scheme.primaryContainer;
+      fg = scheme.onPrimaryContainer;
+    } else {
+      bg = scheme.surfaceContainerHighest;
+      fg = scheme.onSurface;
+    }
+
+    final radius = BorderRadius.only(
+      topLeft: const Radius.circular(18),
+      topRight: const Radius.circular(18),
+      bottomLeft: Radius.circular(isMine ? 18 : 4),
+      bottomRight: Radius.circular(isMine ? 4 : 18),
+    );
 
     final bubble = Container(
-      constraints: BoxConstraints(maxWidth: MediaQuery.sizeOf(context).width * 0.78),
-      margin: const EdgeInsets.symmetric(vertical: 4, horizontal: 12),
-      padding: const EdgeInsets.fromLTRB(12, 8, 12, 8),
-      decoration: BoxDecoration(
-        color: bg,
-        borderRadius: BorderRadius.circular(14),
-        border: twin
-            ? Border.all(color: theme.colorScheme.tertiary, width: 1.5, strokeAlign: BorderSide.strokeAlignOutside)
-            : null,
-      ),
+      constraints: BoxConstraints(maxWidth: MediaQuery.sizeOf(context).width * 0.76),
+      padding: const EdgeInsets.fromLTRB(14, 10, 14, 8),
+      decoration: BoxDecoration(color: bg, borderRadius: radius),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
+        mainAxisSize: MainAxisSize.min,
         children: [
           if (twin)
             Padding(
-              padding: const EdgeInsets.only(bottom: 4),
-              child: Text(
-                '분신',
-                style: theme.textTheme.labelSmall?.copyWith(
-                  color: theme.colorScheme.tertiary,
-                  fontWeight: FontWeight.w700,
+              padding: const EdgeInsets.only(bottom: 6),
+              child: Row(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Icon(Icons.auto_awesome, size: 13, color: accent),
+                  const SizedBox(width: 4),
+                  Text(
+                    '분신',
+                    style: theme.textTheme.labelSmall?.copyWith(
+                      color: accent,
+                      fontWeight: FontWeight.w800,
+                      letterSpacing: 0.2,
+                    ),
+                  ),
+                ],
+              ),
+            ),
+          if (retracted)
+            Row(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                Icon(Icons.replay, size: 14, color: fg),
+                const SizedBox(width: 4),
+                Text(
+                  '되돌린 메시지',
+                  style: theme.textTheme.bodyMedium?.copyWith(color: fg, fontStyle: FontStyle.italic),
                 ),
-              ),
+              ],
+            )
+          else
+            Text(
+              message.text,
+              style: theme.textTheme.bodyMedium?.copyWith(color: fg, height: 1.35),
             ),
+          const SizedBox(height: 4),
           Text(
-            message.retracted ? '(되돌린 메시지)' : message.text,
-            style: theme.textTheme.bodyMedium?.copyWith(
-              fontStyle: message.retracted ? FontStyle.italic : FontStyle.normal,
-              color: message.retracted ? theme.disabledColor : null,
-            ),
+            _time(message.createdAt),
+            style: theme.textTheme.labelSmall?.copyWith(color: fg.withOpacity(0.55), fontSize: 10),
           ),
-          if (twin && isMine && !message.retracted && onRetract != null)
-            Align(
-              alignment: Alignment.centerRight,
-              child: TextButton(
-                onPressed: onRetract,
-                child: const Text('되돌리기'),
-              ),
-            ),
         ],
       ),
     );
 
-    // Dashed look for twin: overlay a custom painter border when twin.
-    if (!twin) {
-      return Align(
-        alignment: isMine ? Alignment.centerRight : Alignment.centerLeft,
-        child: bubble,
-      );
-    }
+    final content = Column(
+      crossAxisAlignment: isMine ? CrossAxisAlignment.end : CrossAxisAlignment.start,
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        twin
+            ? CustomPaint(
+                painter: _DashedRRectPainter(color: accent, radius: radius),
+                child: bubble,
+              )
+            : bubble,
+        if (twin && isMine && !retracted && onRetract != null)
+          Padding(
+            padding: const EdgeInsets.only(top: 2, right: 4, left: 4),
+            child: TextButton.icon(
+              onPressed: onRetract,
+              style: TextButton.styleFrom(
+                padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
+                minimumSize: Size.zero,
+                tapTargetSize: MaterialTapTargetSize.shrinkWrap,
+                foregroundColor: scheme.onSurfaceVariant,
+                textStyle: const TextStyle(fontSize: 12),
+              ),
+              icon: const Icon(Icons.undo, size: 14),
+              label: const Text('되돌리기'),
+            ),
+          ),
+      ],
+    );
 
-    return Align(
-      alignment: isMine ? Alignment.centerRight : Alignment.centerLeft,
-      child: CustomPaint(
-        painter: _DashedRRectPainter(color: theme.colorScheme.tertiary),
-        child: bubble,
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: 4, horizontal: 12),
+      child: Align(
+        alignment: isMine ? Alignment.centerRight : Alignment.centerLeft,
+        child: content,
       ),
     );
   }
 }
 
 class _DashedRRectPainter extends CustomPainter {
-  _DashedRRectPainter({required this.color});
+  _DashedRRectPainter({required this.color, required this.radius});
+
   final Color color;
+  final BorderRadius radius;
 
   @override
   void paint(Canvas canvas, Size size) {
     final paint = Paint()
       ..color = color
       ..style = PaintingStyle.stroke
-      ..strokeWidth = 1.5;
-    final rrect = RRect.fromRectAndRadius(
-      Rect.fromLTWH(1, 1, size.width - 2, size.height - 2),
-      const Radius.circular(14),
-    );
+      ..strokeWidth = 1.4;
+    final rrect = radius.toRRect(Rect.fromLTWH(0.7, 0.7, size.width - 1.4, size.height - 1.4));
     final path = Path()..addRRect(rrect);
     final dashed = _dashPath(path, dashLength: 5, gapLength: 4);
     canvas.drawPath(dashed, paint);
@@ -119,5 +177,6 @@ class _DashedRRectPainter extends CustomPainter {
   }
 
   @override
-  bool shouldRepaint(covariant _DashedRRectPainter oldDelegate) => oldDelegate.color != color;
+  bool shouldRepaint(covariant _DashedRRectPainter oldDelegate) =>
+      oldDelegate.color != color || oldDelegate.radius != radius;
 }