:root {
  --bg: #f5f6f8;
  --card: #ffffff;
  --primary: #0c447c;
  --primary-soft: #e6f1fb;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #185fa5;
  --green: #16a34a;
  --red: #dc2626;
  --radius: 16px;
}

* {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

#app {
  max-width: 480px;
  margin: 0 auto;
  padding: 0 16px 40px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0 12px;
}

.topbar h1 {
  font-size: 20px;
  font-weight: 600;
  margin: 0;
  color: var(--primary);
}

.phase {
  font-size: 13px;
  color: var(--primary);
  background: var(--primary-soft);
  padding: 5px 12px;
  border-radius: 999px;
}

.screen {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.hidden {
  display: none !important;
}

/* 开始页 */
.hero {
  text-align: center;
  margin: 60px 0 40px;
}

.hero-title {
  font-size: 26px;
  font-weight: 700;
  color: var(--primary);
  margin: 0 0 12px;
}

.hero-sub {
  font-size: 15px;
  color: var(--muted);
  margin: 0;
  line-height: 1.6;
}

.btn-primary {
  display: block;
  width: 100%;
  padding: 16px;
  font-size: 17px;
  font-weight: 600;
  color: #fff;
  background: var(--primary);
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
}

.btn-primary:active {
  opacity: 0.9;
}

/* 训练页 */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
}

.listen-controls {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.btn-small {
  font-size: 13px;
  color: var(--accent);
  background: var(--primary-soft);
  border: none;
  border-radius: 8px;
  padding: 8px 12px;
  cursor: pointer;
}

.btn-small.active {
  background: var(--primary);
  color: #fff;
}

.question-text {
  font-size: 22px;
  font-weight: 600;
  margin: 0;
  line-height: 1.5;
}

.question-cn {
  font-size: 15px;
  color: var(--muted);
  margin: 10px 0 0;
}

.feedback {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
}

.transcript {
  font-size: 14px;
  color: var(--muted);
  margin: 0 0 10px;
}

.correction {
  font-size: 15px;
  margin-bottom: 6px;
}

.correction .wrong {
  color: var(--red);
}

.correction .better {
  color: var(--green);
  font-weight: 600;
}

.model-answer {
  font-size: 15px;
  color: var(--text);
  margin: 10px 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--border);
}

.actions {
  display: flex;
  gap: 10px;
  margin-top: 14px;
}

.btn-secondary {
  flex: 1;
  padding: 12px;
  font-size: 15px;
  font-weight: 600;
  color: var(--primary);
  background: #fff;
  border: 1px solid var(--primary);
  border-radius: 12px;
  cursor: pointer;
}

.btn-secondary:active {
  background: var(--primary-soft);
}

/* 麦克风 */
.mic-wrap {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 24px 0 12px;
}

.mic {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  border: none;
  background: var(--primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 6px 20px rgba(12, 68, 124, 0.25);
}

.mic.recording {
  background: var(--red);
}

.mic-icon {
  width: 36px;
  height: 36px;
  border: 3px solid #fff;
  border-radius: 999px;
  position: relative;
}

.mic-icon::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -14px;
  transform: translateX(-50%);
  width: 3px;
  height: 12px;
  background: #fff;
  border-radius: 3px;
}

.mic-hint {
  font-size: 13px;
  color: var(--muted);
  margin-top: 14px;
}