/* TTS按钮和控制面板样式 */
:root {
  --tts-primary-color: #4a90e2;
  --tts-hover-color: #2a6fc9;
  --tts-background-color: #ffffff;
  --tts-text-color: #333333;
  --tts-border-color: #e0e0e0;
  --tts-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  --tts-transition: all 0.3s ease;
}

/* 暗色模式支持 */
@media (prefers-color-scheme: dark) {
  :root {
    --tts-background-color: #1e1e1e;
    --tts-text-color: #f0f0f0;
    --tts-border-color: #333333;
  }
}

/* 主浮动操作按钮 (FAB) */
.main-fab {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 50px;
  height: 50px;
  background-color: #007bff; /* 蓝色 */
  color: white;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
  z-index: 1000;
  transition: background-color 0.3s, transform 0.3s, box-shadow 0.3s;
}

.main-fab:hover {
  background-color: #0056b3; /* 深蓝色 */
  transform: scale(1.05);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.3);
}

.main-fab svg {
  width: 24px;
  height: 24px;
  fill: currentColor;
  transition: transform 0.3s ease;
}

/* 主FAB激活时旋转图标 */
.main-fab.active .main-fab-icon {
  transform: rotate(45deg);
}

/* 子按钮容器 */
.sub-buttons-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 50px;
  height: 50px;
  z-index: 999;
  pointer-events: none; /* 默认禁用点击事件 */
}

/* 子按钮展开时的样式 */
.sub-buttons-container.active {
  pointer-events: auto; /* 激活时启用点击事件 */
}

/* 单个子按钮 */
.sub-button {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 45px;
  height: 45px;
  background-color: #6c757d; /* 灰色 */
  color: white;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
  opacity: 0;
  transform: scale(0.8);
  transition: all 0.3s cubic-bezier(0.68, -0.55, 0.27, 1.55);
}

.sub-button:hover {
  background-color: #5a6268; /* 深灰色 */
  transform: scale(0.9);
}

.sub-button svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

/* 返回按钮的特定颜色 */
.sub-button.back-button {
  background-color: #28a745; /* 绿色 */
}

.sub-button.back-button:hover {
  background-color: #218838; /* 深绿色 */
}

/* TTS子按钮的特定颜色 */
.sub-button.tts-sub-button {
  background-color: #17a2b8; /* 青色 */
}

.sub-button.tts-sub-button:hover {
  background-color: #138496; /* 深青色 */
}

/* 子按钮展开时的位置和可见性 */
.sub-buttons-container.active .sub-button:nth-child(1) { /* 返回按钮 */
  opacity: 1;
  transform: translateY(-70px) scale(1);
}

.sub-buttons-container.active .sub-button:nth-child(2) { /* TTS按钮 */
  opacity: 1;
  transform: translateY(-130px) scale(1);
}

/* TTS控制面板 */
.tts-panel {
  position: fixed;
  bottom: 6rem;
  right: 2rem;
  width: 280px;
  background: var(--tts-background-color);
  border-radius: 8px;
  box-shadow: var(--tts-shadow);
  padding: 1rem;
  z-index: 98;
  transition: var(--tts-transition);
  transform: translateY(20px);
  opacity: 0;
  visibility: hidden;
  color: var(--tts-text-color);
  border: 1px solid var(--tts-border-color);
}

.tts-panel.active {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

.tts-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--tts-border-color);
}

.tts-panel-title {
  font-weight: bold;
  font-size: 1rem;
  margin: 0;
}

.tts-panel-close {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--tts-text-color);
  font-size: 1.2rem;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.tts-controls {
  display: flex;
  justify-content: center;
  margin-bottom: 1rem;
}

.tts-play-button {
  background: var(--tts-primary-color);
  color: white;
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--tts-transition);
}

.tts-play-button:hover {
  background: var(--tts-hover-color);
}

.tts-play-button svg {
  width: 20px;
  height: 20px;
  fill: white;
}

.tts-settings {
  margin-top: 1rem;
}

.tts-setting-item {
  margin-bottom: 0.8rem;
}

.tts-setting-label {
  display: block;
  margin-bottom: 0.3rem;
  font-size: 0.9rem;
}

.tts-range-container {
  display: flex;
  align-items: center;
}

.tts-range {
  flex: 1;
  -webkit-appearance: none;
  height: 6px;
  background: var(--tts-border-color);
  border-radius: 3px;
  outline: none;
}

.tts-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--tts-primary-color);
  cursor: pointer;
}

.tts-range::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--tts-primary-color);
  cursor: pointer;
  border: none;
}

.tts-range-value {
  width: 40px;
  text-align: center;
  margin-left: 10px;
  font-size: 0.9rem;
}

.tts-status {
  font-size: 0.85rem;
  text-align: center;
  margin-top: 0.5rem;
  color: #666;
  min-height: 1.5em;
}

/* 移动端适配 */
@media (max-width: 768px) {
  .main-fab {
    width: 45px;
    height: 45px;
    bottom: 1.5rem;
    right: 1.5rem;
  }

  .sub-buttons-container {
    bottom: 1.5rem;
    right: 1.5rem;
  }

  .sub-button {
    width: 40px;
    height: 40px;
  }

  .sub-buttons-container.active .sub-button:nth-child(1) { /* 返回按钮 */
    transform: translateY(-60px) scale(1);
  }
  
  .sub-buttons-container.active .sub-button:nth-child(2) { /* TTS按钮 */
    transform: translateY(-110px) scale(1);
  }
  
  .tts-panel {
    width: calc(100% - 3rem);
    right: 1.5rem;
    bottom: 5rem;
  }
}