fix(lyric): 桌面歌词三处 UI 问题（主题色重置/延迟控件遮挡/锁图标淡出）

- 主题色面板新增'恢复默认'按钮，接入已有 resetThemeColor（此前设置自定义
  主题色后无任何入口可关闭，#591）
- 全屏歌词页的歌词延迟调整控件 bottom 从 16px 提至 96px，越过钉底的
  PlayBar（80px, z-index 9999），不再被遮挡无法点击（#592）
- 锁定态锁图标增加空闲淡出：无鼠标活动 2.5s 后隐藏并恢复点击穿透，
  mousemove（forward:true 转发）即重新唤出，移出窗口立即隐藏（#606）

Closes #591
Closes #592
Closes #606

src/i18n/lang/en-US/settings.ts

@@ -400,6 +400,7 @@ export default {
   themeColor: {
     title: 'Lyric Theme Color',
     presetColors: 'Preset Colors',
+    reset: 'Reset to Default',
     customColor: 'Custom Color',
     preview: 'Preview',
     previewText: 'Lyric Effect',

src/i18n/lang/ja-JP/settings.ts

@@ -399,6 +399,7 @@ export default {
   themeColor: {
     title: '歌詞テーマカラー',
     presetColors: 'プリセットカラー',
+    reset: 'デフォルトに戻す',
     customColor: 'カスタムカラー',
     preview: 'プレビュー効果',
     previewText: '歌詞効果',

src/i18n/lang/ko-KR/settings.ts

@@ -400,6 +400,7 @@ export default {
   themeColor: {
     title: '가사 테마 색상',
     presetColors: '미리 설정된 색상',
+    reset: '기본값으로 복원',
     customColor: '사용자 정의 색상',
     preview: '미리보기 효과',
     previewText: '가사 효과',

src/i18n/lang/zh-CN/settings.ts

@@ -396,6 +396,7 @@ export default {
   themeColor: {
     title: '歌词主题色',
     presetColors: '预设颜色',
+    reset: '恢复默认',
     customColor: '自定义颜色',
     preview: '预览效果',
     previewText: '歌词效果',

src/i18n/lang/zh-Hant/settings.ts

@@ -387,6 +387,7 @@ export default {
   themeColor: {
     title: '歌詞主題色',
     presetColors: '預設顏色',
+    reset: '恢復預設',
     customColor: '自訂顏色',
     preview: '預覽效果',
     previewText: '歌詞效果',

src/renderer/components/lyric/LyricCorrectionControl.vue

@@ -48,7 +48,8 @@ const { t } = useI18n();
 
 <style scoped lang="scss">
 .lyric-correction {
-  @apply absolute right-0 bottom-4 flex flex-col items-center space-y-1 z-50 select-none transition-opacity duration-200 opacity-0 pointer-events-none;
+  /* bottom 需越过全屏态下钉底的 PlayBar（h-20=80px, z-index:9999），否则被遮挡无法点击（#592） */
+  @apply absolute right-0 bottom-24 flex flex-col items-center space-y-1 z-50 select-none transition-opacity duration-200 opacity-0 pointer-events-none;
 }
 
 .lyric-correction-btn {

src/renderer/components/lyric/ThemeColorPanel.vue

@@ -7,8 +7,14 @@
   >
     <div class="panel-header">
       <span class="panel-title">{{ t('settings.themeColor.title') }}</span>
-      <div class="close-button" @click="handleClose">
-        <i class="ri-close-line"></i>
+      <div class="header-actions">
+        <div class="reset-button" :title="t('settings.themeColor.reset')" @click="handleReset">
+          <i class="ri-arrow-go-back-line"></i>
+          <span>{{ t('settings.themeColor.reset') }}</span>
+        </div>
+        <div class="close-button" @click="handleClose">
+          <i class="ri-close-line"></i>
+        </div>
       </div>
     </div>
 
@@ -111,6 +117,7 @@ interface Props {
 interface Emits {
   (e: 'colorChange', _color: string): void;
   (e: 'close'): void;
+  (e: 'reset'): void;
 }
 
 const props = withDefaults(defineProps<Props>(), {
@@ -160,6 +167,12 @@ const handleClose = () => {
   emit('close');
 };
 
+// 恢复默认：关闭自定义主题色（#591 此前设置后无任何入口可关闭）
+const handleReset = () => {
+  showColorPicker.value = false;
+  emit('reset');
+};
+
 const handlePresetColorSelect = (color: LyricThemeColor) => {
   const colorValue = getColorValue(color);
   const optimizedColor = optimizeColorForTheme(colorValue, props.theme);
@@ -301,6 +314,35 @@ watch(
     opacity: 0.9;
   }
 
+  .header-actions {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+  }
+
+  .reset-button {
+    display: flex;
+    align-items: center;
+    gap: 4px;
+    height: 24px;
+    padding: 0 8px;
+    cursor: pointer;
+    border-radius: 6px;
+    color: var(--text-color);
+    font-size: 11px;
+    opacity: 0.8;
+    transition: all 0.2s ease;
+
+    &:hover {
+      background: rgba(255, 255, 255, 0.15);
+      opacity: 1;
+    }
+
+    i {
+      font-size: 12px;
+    }
+  }
+
   .close-button {
     width: 24px;
     height: 24px;

src/renderer/views/lyric/index.vue

@@ -95,6 +95,7 @@
       :theme="lyricSetting.theme"
       @color-change="handleColorChange"
       @close="handleThemeColorPanelClose"
+      @reset="handleThemeColorReset"
     />
 
     <!-- 歌词显示区域 -->
@@ -365,6 +366,36 @@ const clearHideTimer = () => {
   }
 };
 
+// 锁定态下锁图标空闲自动淡出（#606）：
+// 光标在窗口内且无活动 2.5s 后隐藏并恢复点击穿透；再次移动鼠标即重新唤出
+const LOCKED_CONTROLS_HIDE_DELAY = 2500;
+
+const scheduleLockedControlsHide = () => {
+  clearHideTimer();
+  hideControlsTimer = window.setTimeout(() => {
+    hideControlsTimer = null;
+    if (lyricSetting.value.isLock) {
+      isHovering.value = false;
+      windowData.electron.ipcRenderer.send('set-ignore-mouse', true);
+    }
+  }, LOCKED_CONTROLS_HIDE_DELAY);
+};
+
+const showLockedControls = () => {
+  if (!lyricSetting.value.isLock) return;
+  if (!isHovering.value) {
+    isHovering.value = true;
+    windowData.electron.ipcRenderer.send('set-ignore-mouse', false);
+  }
+  scheduleLockedControlsHide();
+};
+
+// 点击穿透开启时主进程以 forward:true 转发 mousemove，可用于重新唤出锁图标
+const handleLockedMouseMove = () => {
+  if (!lyricSetting.value.isLock) return;
+  showLockedControls();
+};
+
 // 处理鼠标进入窗口
 const handleMouseEnter = () => {
   if (lyricSetting.value.isLock) {
@@ -396,6 +427,7 @@ const handleMouseLeave = () => {
 watch(
   () => lyricSetting.value.isLock,
   (newLock: boolean) => {
+    clearHideTimer();
     if (newLock) {
       isHovering.value = false;
       // 锁定时自动关闭主题色面板
@@ -410,10 +442,12 @@ onMounted(() => {
   if (lyricSetting.value.isLock) {
     isHovering.value = false;
   }
+  document.addEventListener('mousemove', handleLockedMouseMove);
 });
 
 onUnmounted(() => {
   clearHideTimer();
+  document.removeEventListener('mousemove', handleLockedMouseMove);
 });
 
 // 计算歌词滚动位置
@@ -788,10 +822,18 @@ onMounted(() => {
   removeMousePresenceListener = window.ipcRenderer.on(
     'lyric-mouse-presence',
     (isInside: boolean) => {
-      isHovering.value = isInside;
-
       if (lyricSetting.value.isLock) {
-        windowData.electron.ipcRenderer.send('set-ignore-mouse', !isInside);
+        if (isInside) {
+          // 进入窗口：显示锁图标并启动空闲淡出定时器（#606）
+          showLockedControls();
+        } else {
+          // 离开窗口：立即隐藏并恢复点击穿透
+          clearHideTimer();
+          isHovering.value = false;
+          windowData.electron.ipcRenderer.send('set-ignore-mouse', true);
+        }
+      } else {
+        isHovering.value = isInside;
       }
     }
   );
@@ -849,7 +891,13 @@ const handleThemeColorPanelClose = () => {
   showThemeColorPanel.value = false;
 };
 
-// 导出重置函数以供将来使用
+// 面板"恢复默认"：关闭自定义主题色并收起面板（#591）
+const handleThemeColorReset = () => {
+  resetThemeColor();
+  showThemeColorPanel.value = false;
+};
+
+// 重置主题色到默认（主题色面板"恢复默认"按钮调用）
 const resetThemeColor = () => {
   // 重置到默认颜色
   const defaultColor = getCurrentLyricThemeColor(lyricSetting.value.theme);