/* 发音按钮样式 */
.speaker-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: none;
  background: #f0f7ff;
  border-radius: 50%;
  cursor: pointer;
  font-size: 16px;
  line-height: 1;
  transition: all 0.2s ease;
  vertical-align: middle;
  margin-left: 8px;
  padding: 0;
}

.speaker-btn:hover {
  background: #d0e5ff;
  transform: scale(1.15);
}

.speaker-btn:active {
  transform: scale(0.95);
}

.speaker-btn.playing {
  background: #4caf50;
  color: white;
  animation: pulse 0.6s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.2); }
}

/* 测验选项中的发音按钮（小号） */
.quiz-speaker-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border: none;
  background: #f5f5f5;
  border-radius: 50%;
  cursor: pointer;
  font-size: 12px;
  line-height: 1;
  transition: all 0.2s ease;
  vertical-align: middle;
  margin-left: 6px;
  padding: 0;
}

.quiz-speaker-btn:hover {
  background: #e0e0e0;
  transform: scale(1.15);
}