style(ui): 统一页面字号间距与状态样式

lib/pages/downloads/downloads_page.dart

@@ -13,6 +13,7 @@ import '../../core/formatting/error_text.dart';
 import '../../core/formatting/localized_date_time.dart';
 import '../../core/platform/haptics.dart';
 import '../../core/theme/app_colors.dart';
+import '../../core/theme/app_dimens.dart';
 import '../../core/theme/app_theme.dart';
 import '../../core/widgets/auth_gate.dart';
 import '../../core/widgets/empty_state.dart';
@@ -60,9 +61,12 @@ class _DownloadsPageState extends State<DownloadsPage> {
           foregroundColor: Colors.white,
           title: Text(l10n.downloads),
         ),
-        body: signedIn
-            ? _DownloadsBody(downloads: context.watch<DownloadController>())
-            : const AuthGatePanel(),
+        body: SafeArea(
+          top: false,
+          child: signedIn
+              ? _DownloadsBody(downloads: context.watch<DownloadController>())
+              : const AuthGatePanel(),
+        ),
       ),
     );
   }
@@ -194,11 +198,11 @@ class _PolicyPanel extends StatelessWidget {
     final l10n = AppLocalizations.of(context)!;
     return Container(
       key: const Key('download-policy'),
-      padding: const EdgeInsets.fromLTRB(14, 14, 14, 10),
+      padding: const EdgeInsets.fromLTRB(16, 16, 16, 12),
       decoration: BoxDecoration(
         color: AppColors.card,
-        borderRadius: BorderRadius.circular(12),
-        border: Border.all(color: const Color(0xFF2A2C33)),
+        borderRadius: BorderRadius.circular(AppDimens.innerRadius),
+        border: Border.all(color: AppColors.outlineVariantDark),
       ),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
@@ -219,15 +223,21 @@ class _PolicyPanel extends StatelessWidget {
           const SizedBox(height: 6),
           Text(
             policy.expirePolicyText,
-            style: const TextStyle(color: Color(0xFFB7B3B8), fontSize: 12),
+            style: const TextStyle(
+              color: AppColors.muted,
+              fontSize: AppDimens.caption,
+            ),
           ),
-          const Divider(height: 22, color: Color(0xFF2A2C33)),
+          const Divider(height: 22, color: AppColors.outlineVariantDark),
           Row(
             children: [
               Expanded(
                 child: Text(
                   l10n.downloadWifiOnly,
-                  style: const TextStyle(color: Colors.white, fontSize: 13),
+                  style: const TextStyle(
+                    color: Colors.white,
+                    fontSize: AppDimens.body,
+                  ),
                 ),
               ),
               Switch(
@@ -242,7 +252,10 @@ class _PolicyPanel extends StatelessWidget {
               Expanded(
                 child: Text(
                   l10n.downloadQuality,
-                  style: const TextStyle(color: Colors.white, fontSize: 13),
+                  style: const TextStyle(
+                    color: Colors.white,
+                    fontSize: AppDimens.body,
+                  ),
                 ),
               ),
               DropdownButton<String>(
@@ -302,7 +315,7 @@ class _LicenseTile extends StatelessWidget {
       padding: const EdgeInsets.all(12),
       decoration: BoxDecoration(
         color: AppColors.card,
-        borderRadius: BorderRadius.circular(10),
+        borderRadius: BorderRadius.circular(AppDimens.innerRadius),
       ),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
@@ -355,10 +368,12 @@ class _LicenseTile extends StatelessWidget {
           ),
           const SizedBox(height: 8),
           ClipRRect(
-            borderRadius: BorderRadius.circular(4),
+            borderRadius: BorderRadius.circular(AppDimens.progressRadius),
             child: LinearProgressIndicator(
-              minHeight: 4,
+              minHeight: AppDimens.progressHeight,
               value: (license.progressPercent / 100).clamp(0.0, 1.0),
+              backgroundColor: Colors.white24,
+              valueColor: const AlwaysStoppedAnimation(AppColors.blueSoft),
             ),
           ),
           if (license.expireAt != null) ...[
@@ -367,7 +382,10 @@ class _LicenseTile extends StatelessWidget {
               l10n.downloadExpiresAt(
                 formatLocalizedDateTime(context, license.expireAt!),
               ),
-              style: const TextStyle(color: Color(0xFF8D8990), fontSize: 11),
+              style: const TextStyle(
+                color: AppColors.muted,
+                fontSize: AppDimens.caption,
+              ),
             ),
           ],
         ],