diff --git a/frontend/src/components/layout/ThemePicker.tsx b/frontend/src/components/layout/ThemePicker.tsx
index bedf400..2f9b3b8 100644
--- a/frontend/src/components/layout/ThemePicker.tsx
+++ b/frontend/src/components/layout/ThemePicker.tsx
@@ -1,12 +1,8 @@
-// 全局主题选择器 — Header / Login 共用，分组展示主流与开发者主题 // Logan.Li
+// 全局主题选择器 — Header / Login 共用，双主题 + 跟随系统 // Logan.Li
 import { Check } from 'lucide-react';
 import { cn } from '@/lib/utils';
-import {
-  DropdownMenuItem,
-  DropdownMenuLabel,
-  DropdownMenuSeparator,
-} from '@/components/ui/dropdown-menu';
-import { THEME_GROUPS, type ThemePreference } from '@/utils/theme';
+import { DropdownMenuItem } from '@/components/ui/dropdown-menu';
+import { THEME_OPTIONS, type ThemePreference } from '@/utils/theme';
 
 interface ThemePickerProps {
   value: ThemePreference;
@@ -16,46 +12,36 @@ interface ThemePickerProps {
 export function ThemePicker({ value, onChange }: ThemePickerProps) {
   return (
     <>
-      {THEME_GROUPS.map((group, gi) => (
-        <div key={group.label}>
-          {gi > 0 && <DropdownMenuSeparator className="bg-[var(--border-default)]" />}
-          <DropdownMenuLabel className="text-xs dg-text-muted font-normal py-1">
-            {group.label}
-          </DropdownMenuLabel>
-          {group.options.map((option) => (
-            <DropdownMenuItem
-              key={option.id}
-              className={cn(
-                'flex items-center gap-2.5 cursor-pointer transition-colors',
-                'focus:bg-[var(--surface-hover)] focus:text-[var(--text-primary)]',
-                value === option.id
-                  ? 'text-[var(--text-primary)]'
-                  : 'dg-text-secondary',
-              )}
-              onClick={() => onChange(option.id)}
-            >
-              <span
-                className="w-3.5 h-3.5 rounded-full shrink-0"
-                style={{
-                  background: option.primaryColor.startsWith('linear')
-                    ? option.primaryColor
-                    : option.primaryColor,
-                  boxShadow: '0 0 0 2px var(--surface-canvas)',
-                }}
-              />
-              <div className="flex-1 min-w-0">
-                <span className="text-sm font-medium">{option.name}</span>
-                <span className="block text-xs dg-text-muted truncate">
-                  {option.description}
-                </span>
-              </div>
-              {value === option.id && (
-                <Check className="h-4 w-4 text-[var(--brand)] shrink-0" />
-              )}
-            </DropdownMenuItem>
-          ))}
-        </div>
+      {THEME_OPTIONS.map((option) => (
+        <DropdownMenuItem
+          key={option.id}
+          className={cn(
+            'flex items-center gap-2.5 cursor-pointer transition-colors',
+            'focus:bg-[var(--surface-hover)] focus:text-[var(--text-primary)]',
+            value === option.id
+              ? 'text-[var(--text-primary)]'
+              : 'dg-text-secondary',
+          )}
+          onClick={() => onChange(option.id)}
+        >
+          <span
+            className="w-3.5 h-3.5 rounded-full shrink-0"
+            style={{
+              background: option.primaryColor,
+              boxShadow: '0 0 0 2px var(--surface-canvas)',
+            }}
+          />
+          <div className="flex-1 min-w-0">
+            <span className="text-sm font-medium">{option.name}</span>
+            <span className="block text-xs dg-text-muted truncate">
+              {option.description}
+            </span>
+          </div>
+          {value === option.id && (
+            <Check className="h-4 w-4 text-[var(--brand)] shrink-0" />
+          )}
+        </DropdownMenuItem>
       ))}
     </>
   );
-}
\ No newline at end of file
+}
diff --git a/frontend/src/index.css b/frontend/src/index.css
index 1bcca8c..b175a4f 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -136,339 +136,6 @@
     --skeleton-base: #f0f1f5;
     --skeleton-highlight: #e8eaef;
   }
-
-  /* ===== Theme 3: One Dark — Atom 暖灰 IDE（刻意与深海蓝蓝黑区分） // Logan.Li ===== */
-  [data-theme="one-dark"] {
-    --background: 220 9% 22%;
-    --foreground: 220 8% 82%;
-    --card: 220 8% 26%;
-    --card-foreground: 220 8% 82%;
-    --popover: 220 8% 24%;
-    --popover-foreground: 220 8% 82%;
-    --primary: 207 82% 66%;
-    --primary-foreground: 220 9% 18%;
-    --secondary: 220 8% 30%;
-    --secondary-foreground: 220 8% 82%;
-    --muted: 220 8% 30%;
-    --muted-foreground: 220 6% 52%;
-    --accent: 220 8% 30%;
-    --accent-foreground: 220 8% 82%;
-    --destructive: 355 65% 65%;
-    --destructive-foreground: 220 9% 18%;
-    --border: 220 7% 34%;
-    --input: 220 8% 28%;
-    --ring: 286 60% 67%;
-    --radius: 0.625rem;
-    --sidebar-background: 220 9% 17%;
-    --sidebar-foreground: 220 8% 78%;
-    --sidebar-primary: 207 82% 66%;
-    --sidebar-primary-foreground: 220 9% 18%;
-    --sidebar-accent: 220 8% 26%;
-    --sidebar-accent-foreground: 220 8% 82%;
-    --sidebar-border: 220 7% 28%;
-    --sidebar-ring: 286 60% 67%;
-    /* 更亮暖灰底 + 侧栏压暗，贴近 Atom 编辑器层次 */
-    --dg-bg-primary: #282c34;
-    --dg-bg-secondary: #2f343e;
-    --dg-bg-tertiary: #383e4a;
-    --dg-bg-hover: #3e4451;
-    --dg-bg-active: #4b5263;
-    --dg-border: #4b5263;
-    --dg-border-light: #353b45;
-    --dg-border-hover: #5c6370;
-    --dg-text-primary: #d7dae0;
-    --dg-text-secondary: #9da5b4;
-    --dg-text-muted: #6b7285;
-    /* Atom 语法高亮色 — 品牌渐变用紫→绿，非深海蓝 */
-    --dg-blue: #61afef;
-    --dg-green: #98c379;
-    --dg-red: #e06c75;
-    --dg-orange: #d19a66;
-    --dg-purple: #c678dd;
-    --dg-cyan: #56b6c2;
-    --dg-yellow: #e5c07b;
-    --dg-card-hover-border: rgba(198, 120, 221, 0.42);
-    --dg-gradient-start: #c678dd;
-    --dg-gradient-end: #98c379;
-    --dg-gradient-text-start: #c678dd;
-    --dg-gradient-text-end: #61afef;
-    --dg-input-focus-ring: rgba(198, 120, 221, 0.22);
-    --chart-grid: #4b5263;
-    --chart-axis: #6b7285;
-    --chart-tooltip-bg: #2f343e;
-    --chart-tooltip-border: #4b5263;
-    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.22), 0 0 0 1px rgba(198, 120, 221, 0.06);
-    --shadow-card-hover: 0 8px 28px rgba(0, 0, 0, 0.32), 0 0 0 1px rgba(152, 195, 121, 0.18);
-    --shadow-dropdown: 0 10px 36px rgba(0, 0, 0, 0.45);
-    --skeleton-base: #383e4a;
-    --skeleton-highlight: #4b5263;
-    --dg-overlay: color-mix(in srgb, #21252b 52%, transparent);
-  }
-
-  /* ===== Theme 4: Catppuccin Mocha ===== */
-  [data-theme="catppuccin"] {
-    --background: 240 21% 15%;
-    --foreground: 226 64% 88%;
-    --card: 240 21% 12%;
-    --card-foreground: 226 64% 88%;
-    --popover: 240 21% 12%;
-    --popover-foreground: 226 64% 88%;
-    --primary: 217 92% 76%;
-    --primary-foreground: 240 21% 15%;
-    --secondary: 237 16% 23%;
-    --secondary-foreground: 226 64% 88%;
-    --muted: 237 16% 23%;
-    --muted-foreground: 228 24% 72%;
-    --accent: 237 16% 23%;
-    --accent-foreground: 226 64% 88%;
-    --destructive: 343 81% 75%;
-    --destructive-foreground: 240 21% 15%;
-    --border: 237 16% 23%;
-    --input: 237 16% 23%;
-    --ring: 217 92% 76%;
-    --radius: 0.625rem;
-    --sidebar-background: 240 23% 9%;
-    --sidebar-foreground: 226 64% 85%;
-    --sidebar-primary: 217 92% 76%;
-    --sidebar-primary-foreground: 240 21% 15%;
-    --sidebar-accent: 237 16% 23%;
-    --sidebar-accent-foreground: 226 64% 88%;
-    --sidebar-border: 237 16% 23%;
-    --sidebar-ring: 217 92% 76%;
-    --dg-bg-primary: #1e1e2e;
-    --dg-bg-secondary: #181825;
-    --dg-bg-tertiary: #313244;
-    --dg-bg-hover: #45475a;
-    --dg-bg-active: #585b70;
-    --dg-border: #45475a;
-    --dg-border-light: #313244;
-    --dg-border-hover: #585b70;
-    --dg-text-primary: #cdd6f4;
-    --dg-text-secondary: #a6adc8;
-    --dg-text-muted: #7f849c;
-    --dg-blue: #89b4fa;
-    --dg-green: #a6e3a1;
-    --dg-red: #f38ba8;
-    --dg-orange: #fab387;
-    --dg-purple: #cba6f7;
-    --dg-cyan: #89dceb;
-    --dg-yellow: #f9e2af;
-    --dg-card-hover-border: rgba(137, 180, 250, 0.45);
-    --dg-gradient-start: #74c7ec;
-    --dg-gradient-end: #cba6f7;
-    --dg-gradient-text-start: #89b4fa;
-    --dg-gradient-text-end: #cba6f7;
-    --dg-input-focus-ring: rgba(137, 180, 250, 0.2);
-    --chart-grid: #45475a;
-    --chart-axis: #7f849c;
-    --chart-tooltip-bg: #181825;
-    --chart-tooltip-border: #45475a;
-    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(137, 180, 250, 0.05);
-    --shadow-card-hover: 0 8px 32px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(137, 180, 250, 0.15);
-    --shadow-dropdown: 0 10px 40px rgba(0, 0, 0, 0.5);
-    --skeleton-base: #313244;
-    --skeleton-highlight: #45475a;
-    --dg-overlay: color-mix(in srgb, #11111b 55%, transparent);
-  }
-
-  /* ===== Theme 5: Dracula — 紫粉经典（高辨识度） // Logan.Li ===== */
-  [data-theme="dracula"] {
-    --background: 231 15% 18%;
-    --foreground: 60 30% 96%;
-    --card: 231 15% 20%;
-    --card-foreground: 60 30% 96%;
-    --popover: 231 15% 20%;
-    --popover-foreground: 60 30% 96%;
-    --primary: 265 89% 78%;
-    --primary-foreground: 231 15% 18%;
-    --secondary: 232 14% 31%;
-    --secondary-foreground: 60 30% 96%;
-    --muted: 232 14% 31%;
-    --muted-foreground: 231 8% 68%;
-    --accent: 232 14% 31%;
-    --accent-foreground: 60 30% 96%;
-    --destructive: 0 100% 67%;
-    --destructive-foreground: 231 15% 18%;
-    --border: 232 14% 31%;
-    --input: 232 14% 31%;
-    --ring: 265 89% 78%;
-    --radius: 0.625rem;
-    --sidebar-background: 231 16% 16%;
-    --sidebar-foreground: 60 25% 92%;
-    --sidebar-primary: 265 89% 78%;
-    --sidebar-primary-foreground: 231 15% 18%;
-    --sidebar-accent: 232 14% 28%;
-    --sidebar-accent-foreground: 60 30% 96%;
-    --sidebar-border: 232 14% 28%;
-    --sidebar-ring: 265 89% 78%;
-    --dg-bg-primary: #282a36;
-    --dg-bg-secondary: #313341;
-    --dg-bg-tertiary: #44475a;
-    --dg-bg-hover: #4d5066;
-    --dg-bg-active: #5a5d78;
-    --dg-border: #44475a;
-    --dg-border-light: #383a4a;
-    --dg-border-hover: #6272a4;
-    --dg-text-primary: #f8f8f2;
-    --dg-text-secondary: #bfbfb5;
-    --dg-text-muted: #8b8b80;
-    --dg-blue: #8be9fd;
-    --dg-green: #50fa7b;
-    --dg-red: #ff5555;
-    --dg-orange: #ffb86c;
-    --dg-purple: #bd93f9;
-    --dg-cyan: #8be9fd;
-    --dg-yellow: #f1fa8c;
-    --dg-card-hover-border: rgba(189, 147, 249, 0.5);
-    --dg-gradient-start: #bd93f9;
-    --dg-gradient-end: #ff79c6;
-    --dg-gradient-text-start: #bd93f9;
-    --dg-gradient-text-end: #ff79c6;
-    --dg-input-focus-ring: rgba(189, 147, 249, 0.25);
-    --chart-grid: #44475a;
-    --chart-axis: #8b8b80;
-    --chart-tooltip-bg: #313341;
-    --chart-tooltip-border: #44475a;
-    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.35), 0 0 0 1px rgba(189, 147, 249, 0.08);
-    --shadow-card-hover: 0 8px 32px rgba(0, 0, 0, 0.45), 0 0 0 1px rgba(255, 121, 198, 0.2);
-    --shadow-dropdown: 0 10px 40px rgba(0, 0, 0, 0.55);
-    --skeleton-base: #44475a;
-    --skeleton-highlight: #4d5066;
-    --dg-overlay: color-mix(in srgb, #191a21 58%, transparent);
-  }
-
-  /* ===== Theme 6: Tokyo Night — 深蓝紫霓虹 // Logan.Li ===== */
-  [data-theme="tokyo-night"] {
-    --background: 235 25% 12%;
-    --foreground: 226 48% 86%;
-    --card: 234 26% 16%;
-    --card-foreground: 226 48% 86%;
-    --popover: 234 26% 16%;
-    --popover-foreground: 226 48% 86%;
-    --primary: 221 70% 72%;
-    --primary-foreground: 235 25% 12%;
-    --secondary: 233 23% 22%;
-    --secondary-foreground: 226 48% 86%;
-    --muted: 233 23% 22%;
-    --muted-foreground: 225 15% 58%;
-    --accent: 233 23% 22%;
-    --accent-foreground: 226 48% 86%;
-    --destructive: 350 65% 72%;
-    --destructive-foreground: 235 25% 12%;
-    --border: 233 20% 26%;
-    --input: 233 23% 22%;
-    --ring: 221 70% 72%;
-    --radius: 0.625rem;
-    --sidebar-background: 235 28% 10%;
-    --sidebar-foreground: 226 45% 84%;
-    --sidebar-primary: 221 70% 72%;
-    --sidebar-primary-foreground: 235 25% 12%;
-    --sidebar-accent: 233 23% 20%;
-    --sidebar-accent-foreground: 226 48% 86%;
-    --sidebar-border: 233 20% 24%;
-    --sidebar-ring: 221 70% 72%;
-    --dg-bg-primary: #1a1b26;
-    --dg-bg-secondary: #24283b;
-    --dg-bg-tertiary: #2f3549;
-    --dg-bg-hover: #3b4261;
-    --dg-bg-active: #414868;
-    --dg-border: #3b4261;
-    --dg-border-light: #292e42;
-    --dg-border-hover: #565f89;
-    --dg-text-primary: #c0caf5;
-    --dg-text-secondary: #9aa5ce;
-    --dg-text-muted: #737aa2;
-    --dg-blue: #7aa2f7;
-    --dg-green: #9ece6a;
-    --dg-red: #f7768e;
-    --dg-orange: #ff9e64;
-    --dg-purple: #bb9af7;
-    --dg-cyan: #7dcfff;
-    --dg-yellow: #e0af68;
-    --dg-card-hover-border: rgba(122, 162, 247, 0.45);
-    --dg-gradient-start: #7aa2f7;
-    --dg-gradient-end: #bb9af7;
-    --dg-gradient-text-start: #7aa2f7;
-    --dg-gradient-text-end: #7dcfff;
-    --dg-input-focus-ring: rgba(122, 162, 247, 0.22);
-    --chart-grid: #3b4261;
-    --chart-axis: #737aa2;
-    --chart-tooltip-bg: #24283b;
-    --chart-tooltip-border: #3b4261;
-    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.35), 0 0 0 1px rgba(122, 162, 247, 0.06);
-    --shadow-card-hover: 0 8px 32px rgba(0, 0, 0, 0.45), 0 0 0 1px rgba(187, 154, 247, 0.18);
-    --shadow-dropdown: 0 10px 40px rgba(0, 0, 0, 0.55);
-    --skeleton-base: #2f3549;
-    --skeleton-highlight: #3b4261;
-    --dg-overlay: color-mix(in srgb, #15161e 58%, transparent);
-  }
-
-  /* ===== Theme 7: Nord（保留兼容，已从选择器下架） // Logan.Li ===== */
-  [data-theme="nord"] {
-    --background: 220 16% 22%;
-    --foreground: 218 27% 92%;
-    --card: 220 16% 19%;
-    --card-foreground: 218 27% 92%;
-    --popover: 220 16% 19%;
-    --popover-foreground: 218 27% 92%;
-    --primary: 193 43% 67%;
-    --primary-foreground: 220 16% 22%;
-    --secondary: 220 16% 28%;
-    --secondary-foreground: 218 27% 92%;
-    --muted: 220 16% 28%;
-    --muted-foreground: 220 16% 56%;
-    --accent: 220 16% 28%;
-    --accent-foreground: 218 27% 92%;
-    --destructive: 354 42% 56%;
-    --destructive-foreground: 218 27% 92%;
-    --border: 220 16% 28%;
-    --input: 220 16% 28%;
-    --ring: 193 43% 67%;
-    --radius: 0.625rem;
-    --sidebar-background: 220 16% 18%;
-    --sidebar-foreground: 218 27% 88%;
-    --sidebar-primary: 193 43% 67%;
-    --sidebar-primary-foreground: 220 16% 22%;
-    --sidebar-accent: 220 16% 28%;
-    --sidebar-accent-foreground: 218 27% 92%;
-    --sidebar-border: 220 16% 28%;
-    --sidebar-ring: 193 43% 67%;
-    --dg-bg-primary: #2e3440;
-    --dg-bg-secondary: #3b4252;
-    --dg-bg-tertiary: #434c5e;
-    --dg-bg-hover: #4c566a;
-    --dg-bg-active: #5e6a7e;
-    --dg-border: #4c566a;
-    --dg-border-light: #434c5e;
-    --dg-border-hover: #5e6a7e;
-    --dg-text-primary: #eceff4;
-    --dg-text-secondary: #d8dee9;
-    --dg-text-muted: #a0a8b8;
-    --dg-blue: #81a1c1;
-    --dg-green: #a3be8c;
-    --dg-red: #bf616a;
-    --dg-orange: #d08770;
-    --dg-purple: #b48ead;
-    --dg-cyan: #88c0d0;
-    --dg-yellow: #ebcb8b;
-    --dg-card-hover-border: rgba(136, 192, 208, 0.45);
-    --dg-gradient-start: #5e81ac;
-    --dg-gradient-end: #88c0d0;
-    --dg-gradient-text-start: #88c0d0;
-    --dg-gradient-text-end: #81a1c1;
-    --dg-input-focus-ring: rgba(136, 192, 208, 0.2);
-    --chart-grid: #4c566a;
-    --chart-axis: #a0a8b8;
-    --chart-tooltip-bg: #3b4252;
-    --chart-tooltip-border: #4c566a;
-    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(136, 192, 208, 0.05);
-    --shadow-card-hover: 0 8px 32px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(136, 192, 208, 0.15);
-    --shadow-dropdown: 0 10px 40px rgba(0, 0, 0, 0.5);
-    --skeleton-base: #434c5e;
-    --skeleton-highlight: #4c566a;
-    --dg-overlay: color-mix(in srgb, #2e3440 55%, transparent);
-  }
-
   /*
    * ===== AIOps 设计令牌（Design Tokens）// Logan.Li =====
    *
@@ -482,8 +149,7 @@
    * 布局：--space-page 页面区块 | --layout-* 应用壳（侧栏/顶栏/内边距）
    * 告警：--alert-warning-* / --alert-error-* 横幅语义色
    * 主题：data-theme-preference 用户选择 | data-theme 实际生效主题
-   *        主流：system / ocean-deep(蓝黑) / light-professional
-   *        开发者：one-dark(暖灰) / dracula(紫粉) / tokyo-night(霓虹) / catppuccin
+   *        仅保留 双主题：ocean-deep(深海蓝暗色) / light-professional(明亮白浅色) + system 跟随系统
    *
    * 布局层级：dg-app-shell → dg-app-content → PageShell(.dg-page) → ContentPanel
    */
diff --git a/frontend/src/utils/theme.ts b/frontend/src/utils/theme.ts
index ff68c58..b8bcfed 100644
--- a/frontend/src/utils/theme.ts
+++ b/frontend/src/utils/theme.ts
@@ -1,4 +1,4 @@
-// 主题常量与持久化 — 主流主题 + 开发者主题 + 跟随系统 // Logan.Li
+// 主题常量与持久化 — 双主题（深海蓝暗色 / 明亮白浅色）+ 跟随系统 // Logan.Li
 
 import { getItem, setItem, STORAGE_KEYS } from './storage';
 import i18n from '@/i18n';
@@ -7,12 +7,7 @@ import i18n from '@/i18n';
 export type ThemePreference =
   | 'system'
   | 'ocean-deep'
-  | 'light-professional'
-  | 'one-dark'
-  | 'catppuccin'
-  | 'dracula'
-  | 'tokyo-night'
-  | 'nord';
+  | 'light-professional';
 
 /** 实际应用到 data-theme 的具体主题 */
 export type ResolvedTheme = Exclude<ThemePreference, 'system'>;
@@ -30,30 +25,18 @@ export interface ThemeGroup {
   options: ThemeOption[];
 }
 
-/** 主流主题 — 默认推荐 */
+/** 主题清单 — 仅保留一暗一亮，避免多个暗色主题视觉重复 // Logan.Li */
 const MAINSTREAM_THEMES: ThemeOption[] = [
   { id: 'system', name: i18n.t('common.lightDark'), description: i18n.t('common.themets.s17d84295'), isDark: false, primaryColor: 'linear-gradient(135deg, #2563eb 50%, #0d1117 50%)' },
   { id: 'ocean-deep', name: i18n.t('common.themets.s2f82cbb2'), description: i18n.t('common.themets.s29ee972b'), isDark: true, primaryColor: '#0d1117' },
   { id: 'light-professional', name: i18n.t('common.themets.s2d43cc04'), description: i18n.t('common.themets.s37e76182'), isDark: false, primaryColor: '#2563eb' },
 ];
 
-/** 开发者主题 — 高辨识度扩展 */
-const DEVELOPER_THEMES: ThemeOption[] = [
-  { id: 'one-dark', name: 'One Dark', description: i18n.t('common.themets.s02b08e05'), isDark: true, primaryColor: '#c678dd' },
-  { id: 'dracula', name: 'Dracula', description: i18n.t('common.themets.s525ce260'), isDark: true, primaryColor: '#bd93f9' },
-  { id: 'tokyo-night', name: 'Tokyo Night', description: i18n.t('common.themets.s6f40fb5e'), isDark: true, primaryColor: '#7aa2f7' },
-  { id: 'catppuccin', name: 'Catppuccin', description: i18n.t('common.themets.s571aa09d'), isDark: true, primaryColor: '#89b4fa' },
-];
-
 export const THEME_GROUPS: ThemeGroup[] = [
   { label: i18n.t('common.themets.s8392cae7'), options: MAINSTREAM_THEMES },
-  { label: i18n.t('common.themets.sc2e48855'), options: DEVELOPER_THEMES },
 ];
 
-export const THEME_OPTIONS: ThemeOption[] = [
-  ...MAINSTREAM_THEMES,
-  ...DEVELOPER_THEMES,
-];
+export const THEME_OPTIONS: ThemeOption[] = [...MAINSTREAM_THEMES];
 
 export const THEME_ORDER: ThemePreference[] = THEME_OPTIONS.map((o) => o.id);
 export const DEFAULT_THEME: ThemePreference = 'system';
@@ -61,10 +44,15 @@ export const DEFAULT_THEME: ThemePreference = 'system';
 const LEGACY_THEME_MAP: Record<string, ThemePreference> = {
   dark: 'ocean-deep',
   light: 'light-professional',
-  'midnight-purple': 'one-dark',
-  'pine-green': 'catppuccin',
-  'orange-vitality': 'tokyo-night',
-  nord: 'tokyo-night',
+  // 已下架的旧主题与开发者主题统一迁移到深海蓝，保证存量用户不掉样式。 // Logan.Li
+  'midnight-purple': 'ocean-deep',
+  'pine-green': 'ocean-deep',
+  'orange-vitality': 'ocean-deep',
+  nord: 'ocean-deep',
+  'one-dark': 'ocean-deep',
+  dracula: 'ocean-deep',
+  'tokyo-night': 'ocean-deep',
+  catppuccin: 'ocean-deep',
 };
 
 export function migrateLegacyTheme(value: string | null): ThemePreference | null {
@@ -103,11 +91,6 @@ export function getInitialTheme(): ThemePreference {
   if (stored && THEME_ORDER.includes(stored as ThemePreference)) {
     return stored as ThemePreference;
   }
-  /* nord 已下架，自动迁移到 Tokyo Night // Logan.Li */
-  if (stored === 'nord') {
-    setItem(STORAGE_KEYS.theme, 'tokyo-night');
-    return 'tokyo-night';
-  }
   return DEFAULT_THEME;
 }
 
@@ -126,4 +109,4 @@ export function applyThemeToDocument(pref: ThemePreference): void {
 export function getNextTheme(current: ThemePreference): ThemePreference {
   const idx = THEME_ORDER.indexOf(current);
   return THEME_ORDER[(idx + 1) % THEME_ORDER.length];
-}
\ No newline at end of file
+}