/* LearnMusic · 全站共用样式（暖色渐变 · 儿童友好高级感） */

:root {
  --bg: #1a1440;
  --bg-panel: #161a21;
  --bg-card: rgba(255, 255, 255, 0.07);
  --bg-card-hover: rgba(255, 255, 255, 0.13);
  --border: rgba(255, 255, 255, 0.14);
  --text: #f4f2ff;
  --text-dim: rgba(244, 242, 255, 0.72);
  --text-faint: rgba(244, 242, 255, 0.45);
  --accent: #ffc94d;        /* 暖金 */
  --accent-dim: #b98a1e;
  --blue: #7cc7ff;
  --green: #4ade80;
  --red: #f87171;
  --radius: 22px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: linear-gradient(160deg, #2a1b52 0%, #1d2f66 55%, #123047 100%);
  background-attachment: fixed;
  color: var(--text);
  font-family: "PingFang SC", "Yuanti SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap {
  max-width: 960px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

/* ---- 页头 ---- */
.site-header {
  border-bottom: none;
  background: transparent;
}
.site-header .wrap { padding-top: 56px; padding-bottom: 40px; }
.site-title {
  margin: 0 0 8px;
  font-size: 40px;
  font-weight: 800;
  letter-spacing: 2px;
  text-shadow: 0 6px 30px rgba(0, 0, 0, 0.35);
}
.site-title .dot { color: var(--accent); }
.site-subtitle {
  margin: 0;
  color: var(--text-dim);
  font-size: 17px;
}
.site-subtitle strong { color: var(--accent); font-weight: 700; }

.lesson-header { margin-bottom: 32px; }
.lesson-header .back {
  display: inline-block;
  margin-bottom: 12px;
  color: var(--text-dim);
  font-size: 14px;
}
.lesson-header h1 { margin: 0 0 6px; font-size: 30px; }
.lesson-header .lesson-sub { color: var(--text-dim); margin: 0; }

/* ---- 课程卡片网格（主页） ---- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 36px;
}
.card {
  display: block;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 24px 20px;
  color: var(--text);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}
a.card:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-dim);
  transform: translateY(-4px);
  text-decoration: none;
}
.card.disabled {
  opacity: 0.45;
  cursor: default;
  box-shadow: none;
}
.card-num {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  color: var(--accent);
  letter-spacing: 1px;
}
.card.disabled .card-num { color: var(--text-faint); }
.card h2 {
  margin: 6px 0 8px;
  font-size: 22px;
}
.card p {
  margin: 0 0 14px;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.6;
}
.badge {
  display: inline-block;
  padding: 3px 14px;
  border-radius: 999px;
  font-size: 12px;
  border: 1px solid var(--border);
  color: var(--text-faint);
}
.badge.ready {
  color: var(--accent);
  border-color: var(--accent-dim);
  background: rgba(255, 201, 77, 0.12);
}

/* ---- 课件板块 ---- */
.section {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 28px;
}
.section-num {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  color: var(--accent);
  font-size: 13px;
  letter-spacing: 1px;
}
.section h2 { margin: 4px 0 14px; font-size: 22px; }
.section p { margin: 0 0 12px; color: var(--text-dim); }
.section p strong, .section li strong { color: var(--text); }
.section ul { color: var(--text-dim); padding-left: 20px; }

.tip {
  border-left: 3px solid var(--accent-dim);
  background: rgba(232, 182, 71, 0.06);
  padding: 10px 14px;
  border-radius: 0 8px 8px 0;
  font-size: 14px;
  color: var(--text-dim);
  margin: 14px 0 0;
}

/* ---- 按钮 ---- */
.btn {
  display: inline-block;
  border: 1px solid var(--border);
  background: #232936;
  color: var(--text);
  border-radius: 8px;
  padding: 9px 18px;
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.12s ease, border-color 0.12s ease;
  margin: 4px 6px 4px 0;
}
.btn:hover { background: #2c3444; border-color: #3a4356; }
.btn:active { transform: translateY(1px); }
.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #1a1405;
  font-weight: 600;
}
.btn-primary:hover { background: #f2c45e; border-color: #f2c45e; }
.btn.stop-btn { color: var(--red); }
.btn-row { margin: 12px 0; }

/* ---- 调式选择器 ---- */
.mode-btns { margin: 14px 0; }
.mode-btn {
  border: 1px solid var(--border);
  background: #202634;
  color: var(--text);
  border-radius: 8px;
  padding: 8px 14px;
  margin: 4px 6px 4px 0;
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.12s ease;
}
.mode-btn small { color: var(--text-faint); margin-left: 6px; }
.mode-btn:hover { border-color: var(--accent-dim); }
.mode-btn.active {
  background: rgba(232, 182, 71, 0.14);
  border-color: var(--accent);
  color: var(--accent);
}
.mode-btn.active small { color: var(--accent-dim); }

.mode-info {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-top: 14px;
}
.mode-info h3 { margin: 0 0 4px; font-size: 18px; }
.mode-info .mood { color: var(--accent); font-size: 14px; margin: 0 0 10px; }
.mode-info .usage { color: var(--text-dim); font-size: 14px; margin: 8px 0 0; }
.mode-info .label { color: var(--text-faint); font-size: 13px; }

.step-chips { margin: 8px 0; }
.chip {
  display: inline-block;
  min-width: 34px;
  text-align: center;
  padding: 3px 8px;
  margin: 2px 4px 2px 0;
  border-radius: 6px;
  font-size: 13px;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  background: #242b3a;
  border: 1px solid var(--border);
}
.chip.half { background: rgba(76, 194, 255, 0.12); border-color: #2f5d78; color: var(--blue); }

/* ---- 钢琴键盘 ---- */
.lm-kbd {
  position: relative;
  display: flex;
  height: 190px;
  margin: 16px 0 8px;
  user-select: none;
  -webkit-user-select: none;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #111;
}
.lm-kbd-key { cursor: pointer; }
.lm-kbd-fixed { width: max-content; }
.lm-kbd-fixed .lm-kbd-white { flex: 0 0 auto; }
.lm-kbd-white {
  flex: 1;
  background: linear-gradient(180deg, #f4f4f6, #d9dbe0);
  border-right: 1px solid #a9acb5;
  border-bottom: 3px solid #9a9da6;
  position: relative;
}
.lm-kbd-white:last-child { border-right: none; }
.lm-kbd-white.pressed { background: #c6c9d2; }
.lm-kbd-black {
  position: absolute;
  top: 0;
  height: 58%;
  background: linear-gradient(180deg, #2b2e35, #101216);
  border: 1px solid #000;
  border-radius: 0 0 4px 4px;
  z-index: 2;
}
.lm-kbd-black.pressed { background: #3a3e48; }
.lm-kbd-white.hl { background: linear-gradient(180deg, #ffe9b0, var(--accent)); border-bottom-color: var(--accent-dim); }
.lm-kbd-black.hl { background: linear-gradient(180deg, #8a6d2a, #5e4a1c); border-color: var(--accent-dim); }
.lm-kbd-label {
  position: absolute;
  bottom: 6px;
  left: 0;
  right: 0;
  text-align: center;
  font-size: 11px;
  color: #555b66;
  pointer-events: none;
}
.lm-kbd-black .lm-kbd-label { color: #cfd3dc; bottom: 4px; font-size: 10px; }
.lm-kbd-nolabels .lm-kbd-label { display: none; }

.kbd-toolbar {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 13px;
  color: var(--text-dim);
  margin-top: 4px;
}
.kbd-toolbar label { cursor: pointer; }

/* ---- 小测验 ---- */
.quiz-options { margin: 12px 0; }
.quiz-feedback {
  min-height: 28px;
  font-weight: 600;
  margin: 8px 0;
}
.quiz-feedback.ok { color: var(--green); }
.quiz-feedback.bad { color: var(--red); }
.quiz-score { color: var(--text-faint); font-size: 13px; }
.mode-btn.correct { border-color: var(--green); color: var(--green); background: rgba(74, 222, 128, 0.1); }
.mode-btn.wrong { border-color: var(--red); color: var(--red); background: rgba(248, 113, 113, 0.1); }

/* ---- 页脚 ---- */
.site-footer {
  border-top: none;
  margin-top: 48px;
  padding: 24px;
  text-align: center;
  color: var(--text-faint);
  font-size: 13px;
}

@media (max-width: 640px) {
  .site-title { font-size: 26px; }
  .section { padding: 20px; }
  .lm-kbd { height: 150px; }
}