body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f2f6fb;
  padding: 20px;
}

h1 {
  text-align: center;
  color: #333;
}

/******错题挑战关 与 返回按钮 与 音效控制按钮 Start******************/
.head-panel {
  max-width: 700px;
  margin: 0 auto 16px;
  padding: 0 8px;
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
}

.header-center {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

.header-center h1 {
  font-size: 18px;
  margin: 0;
  font-weight: 600;
}

.header-right {
  display: flex;
  gap: 8px;
}

.back-btn {
  position: absolute;
  left: 0;
  top: 0;
  font-size: 13px;
  padding: 6px 10px;
  border-radius: 20px;
  background: #eef3ff;
  color: #4f8cff;
  border: 1px solid #d6e3ff;
  cursor: pointer;
}

.back-btn:hover {
  background: #dfe9ff;
}

.icon-btn {
  border: none;
  background: #f2f4f8;
  border-radius: 10px;
  padding: 6px 10px;
  font-size: 18px;
  cursor: pointer;
  font-size: 13px;
  color: #4f8cff;
}

.icon-btn:hover {
  background: #e0e6f0;
}
/********错题挑战关 与 返回按钮 与 音效控制按钮 End************************/

/* .page-title {
  text-align: center;
  font-size: 22px;
  margin-bottom: 6px;
} */

.page-subtitle {
  text-align: center;
  font-size: 14px;
  color: #666;
  margin-bottom: 16px;
}

/************挑战进度区Start******************** */
.challenge-progress {
  max-width: 700px;
  margin: 0 auto 16px;
  padding: 12px;
  background: #f6f9ff;
  border-radius: 12px;
}

.progress-text {
  font-size: 14px;
  color: #444;
  margin-bottom: 6px;
}

.progress-bar {
  height: 10px;
  background: #e5ecff;
  border-radius: 10px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #4f8cff, #ffc17a);
  transition: width 0.3s ease;
}
/************挑战进度区End******************** */

.controls,
.search-card,
.card {
  background: #fff;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  border-radius: 12px;
}

.controls-panel,
.content-panel,
.search-panel {
  max-width: 700px;
  margin: 0 auto 20px;
}

input, button {
  font-size: 15px;
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid #ccc;
}

button {
  cursor: pointer;
  background: #4f8cff;
  color: white;
  border: none;
}

button.tts {
  background: #28a745;
}

.card {
  margin: 15px auto;
  padding: 15px;
}

.sentence {
  font-size: 18px;
  margin-bottom: 10px;
}

.hidden {
  color: #bbb;
  display: none;
}

.answer {
  margin-top: 8px;
  display: none;
}

.input-row {
  margin-top: 8px;
  display: flex;
  gap: 8px;
}

.input-row input {
  flex: 1;
}


/********练习反馈样式Start*****************/
.feedback-row {
  margin-top: 10px;
  display: flex;
  gap: 10px;
  align-items: center;
  font-size: 14px;
}

.feedback-row button {
  padding: 6px 12px;
  border-radius: 20px;
  border: none;
  cursor: pointer;
}

.feedback-ok {
  background: #e6f6ea;
  color: #207a3c;
}

.feedback-wrong {
  background: #fff4e5;
  color: #a65b00;
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/********练习反馈样式End*****************/

/* 抖动效果start ***********************/
.shake {
  animation: shake 0.3s;
}

@keyframes shake {
  0% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  50% { transform: translateX(4px); }
  75% { transform: translateX(-4px); }
  100% { transform: translateX(0); }
}
/* 抖动效果end ************************/