```

refactor(theme): 统一应用深色主题替换日夜切换功能

- 移除白天主题相关样式定义和切换逻辑
- 将主题系统固定为深色主题（琥珀夜光）
- 更新页面背景色设置为统一深色
- 简化导航栏和标签栏主题应用逻辑
- 移除白天主题的颜色变量和样式类
- 更新主题混入文件以支持单一深色主题
```

common/theme-mixin.js

@@ -1,8 +1,8 @@
 /* 碰盏日记 - 主题混入 (Theme Mixin)
- * 每个页面混入此mixin，自动在onShow时刷新日夜主题
+ * 全局统一深色主题（琥珀夜光），已移除白天主题
  * 页面根视图需绑定 :class="themeClass"
  */
-import { getCurrentTheme, applyTheme } from './utils'
+import { applyTheme } from './utils'
 
 export default {
   data() {
@@ -19,10 +19,10 @@ export default {
   },
   methods: {
     _refreshTheme() {
-      const theme = getCurrentTheme()
-      this.currentTheme = theme
-      this.themeClass = theme === 'light' ? 'theme-light' : 'theme-dark'
-      applyTheme(theme)
+      // 固定深色主题
+      this.currentTheme = 'dark'
+      this.themeClass = 'theme-dark'
+      applyTheme('dark')
     }
   }
 }

common/utils.js

@@ -278,13 +278,10 @@ export function calcLocalStreak(records) {
 }
 
 /**
- * 主题系统：日夜自动切换
- * 白天：6:00-16:00 → light
- * 夜间：16:00-6:00 → dark
+ * 主题系统：全局统一使用深色主题（琥珀夜光），已移除白天主题
  */
 export function getCurrentTheme() {
-  const hour = new Date().getHours()
-  return (hour >= 6 && hour < 16) ? 'light' : 'dark'
+  return 'dark'
 }
 
 export function applyTheme(theme) {
@@ -296,15 +293,11 @@ export function applyTheme(theme) {
 }
 
 export function applyNavBarTheme(theme) {
-  const colors = {
-    dark: { backgroundColor: '#0B0B14', frontColor: '#ffffff' },
-    light: { backgroundColor: '#F2F5F9', frontColor: '#000000' }
-  }
-  const c = colors[theme] || colors.dark
+  // 仅深色主题
   try {
     uni.setNavigationBarColor({
-      frontColor: c.frontColor,
-      backgroundColor: c.backgroundColor,
+      frontColor: '#ffffff',
+      backgroundColor: '#0B0B14',
       animation: { duration: 300, timingFunc: 'easeInOut' }
     })
   } catch (e) {}
@@ -336,21 +329,13 @@ export function applyTabBarTheme(theme) {
   const currentPath = pages[pages.length - 1].route
   if (!tabBarPages.includes(currentPath)) return
 
-  const styles = {
-    dark: {
-      color: '#9494AC',
-      selectedColor: '#E8A838',
-      backgroundColor: '#151520',
-      borderStyle: 'black'
-    },
-    light: {
-      color: '#9BA8BA',
-      selectedColor: '#E09B2D',
-      backgroundColor: '#FFFFFF',
-      borderStyle: 'white'
-    }
+  // 仅深色主题
+  const s = {
+    color: '#9494AC',
+    selectedColor: '#E8A838',
+    backgroundColor: '#151520',
+    borderStyle: 'black'
   }
-  const s = styles[theme] || styles.dark
   try {
     uni.setTabBarStyle({
       color: s.color,
@@ -365,19 +350,19 @@ export function applyTabBarTheme(theme) {
 }
 
 export function getThemeColors(theme) {
-  const isDark = theme !== 'light'
+  // 仅保留深色主题色值（参数保留以兼容既有调用）
   return {
-    textPrimary: isDark ? '#FFFFFF' : '#16233C',
-    textSecondary: isDark ? '#C0C0D2' : '#5D6B82',
-    textTertiary: isDark ? '#9494AC' : '#9BA8BA',
-    amber: isDark ? '#E8A838' : '#E09B2D',
-    bgBase: isDark ? '#0B0B14' : '#F2F5F9',
-    bgCard: isDark ? '#1A1A28' : '#FFFFFF',
-    cardGradStart: isDark ? '#1A1510' : '#F8FAFD',
-    cardGradEnd: isDark ? '#0D0B08' : '#EFF3F9',
-    borderSubtle: isDark ? 'rgba(232,168,56,0.15)' : 'rgba(224,155,45,0.18)',
-    bgPlaceholder: isDark ? 'rgba(255,255,255,0.03)' : 'rgba(22,40,70,0.04)',
-    emojiBg: isDark ? 'rgba(232,168,56,0.08)' : 'rgba(224,155,45,0.10)'
+    textPrimary: '#FFFFFF',
+    textSecondary: '#C0C0D2',
+    textTertiary: '#9494AC',
+    amber: '#E8A838',
+    bgBase: '#0B0B14',
+    bgCard: '#1A1A28',
+    cardGradStart: '#1A1510',
+    cardGradEnd: '#0D0B08',
+    borderSubtle: 'rgba(232,168,56,0.15)',
+    bgPlaceholder: 'rgba(255,255,255,0.03)',
+    emojiBg: 'rgba(232,168,56,0.08)'
   }
 }