:root {
  --bg: #eef2f9;
  --bg-grad: linear-gradient(135deg, #1e3a8a 0%, #2563eb 50%, #0ea5e9 100%);
  --surface: #ffffff;
  --surface-2: #f5f8fd;
  --surface-3: #eaf1fb;
  --border: #e3e9f2;
  --border-strong: #cdd7e6;
  --text: #16233b;
  --muted: #5b6b85;
  --muted-2: #93a1b8;
  --brand: #2563eb;
  --brand-2: #0ea5e9;
  --brand-d: #1d4ed8;
  --accent: #14b8a6;
  --accent-d: #0d9488;
  --warn: #f59e0b;
  --danger: #ef4444;
  --shadow-sm: 0 1px 2px rgba(16,24,40,.06);
  --shadow: 0 8px 26px rgba(16,24,40,.08), 0 1px 3px rgba(16,24,40,.05);
  --radius: 16px;
  --radius-sm: 10px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  background-image: radial-gradient(1200px 500px at 80% -10%, #dbeafe 0%, transparent 60%),
                    radial-gradient(900px 400px at -10% 0%, #e0f2fe 0%, transparent 55%);
  line-height: 1.5;
  padding-bottom: 40px;
  -webkit-font-smoothing: antialiased;
}

kbd {
  font-family: var(--mono);
  font-size: 12px;
  background: #fff;
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  border-radius: 6px;
  padding: 1px 6px;
  color: var(--brand-d);
  white-space: nowrap;
}

/* ---------- top bar ---------- */
.topbar {
  background: var(--bg-grad);
  color: #fff;
  padding: 22px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  box-shadow: var(--shadow);
}
.brand { display: flex; align-items: center; gap: 14px; }
.logo {
  width: 48px; height: 48px;
  display: grid; place-items: center;
  background: rgba(255,255,255,.18);
  border-radius: 14px;
  backdrop-filter: blur(4px);
}
.logo svg { color: #fff; }
.brand-txt h1 { margin: 0; font-size: 22px; font-weight: 700; letter-spacing: .3px; }
.brand-txt .sub { margin: 2px 0 0; font-size: 13px; opacity: .9; }

/* ---------- buttons ---------- */
.btn {
  font-family: var(--font);
  font-size: 14px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text);
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: transform .08s ease, box-shadow .15s ease, background .15s ease, border-color .15s ease;
  white-space: nowrap;
  display: inline-flex; align-items: center; gap: 7px;
}
.btn svg { width: 16px; height: 16px; flex: 0 0 auto; }
.btn:hover:not(:disabled) { box-shadow: var(--shadow-sm); transform: translateY(-1px); }
.btn:active:not(:disabled) { transform: translateY(0); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.primary {
  background: linear-gradient(180deg, #3b82f6 0%, var(--brand-d) 100%);
  border-color: transparent;
  color: #fff;
  font-weight: 600;
  box-shadow: 0 4px 12px rgba(37,99,235,.35);
}
.btn.primary:hover:not(:disabled) { box-shadow: 0 6px 16px rgba(37,99,235,.45); }
.btn.warn { color: var(--warn); border-color: #f5d9a8; }
.btn.warn:hover:not(:disabled) { border-color: var(--warn); }
.btn.ghost-light {
  background: rgba(255,255,255,.16);
  border: 1px solid rgba(255,255,255,.35);
  color: #fff;
  backdrop-filter: blur(4px);
}
.btn.ghost-light svg { color: #fff; }
.btn.ghost-light:hover:not(:disabled) { background: rgba(255,255,255,.28); }

/* ---------- steps stepper ---------- */
.steps {
  list-style: none;
  margin: 18px auto 0;
  padding: 0 24px;
  max-width: 1240px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}
.step {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  position: relative;
  transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}
.step::after {
  content: "";
  position: absolute;
  right: -7px; top: 50%;
  width: 12px; height: 2px;
  background: var(--border-strong);
  z-index: 0;
}
.step:last-child::after { display: none; }
.step .dot {
  flex: 0 0 30px;
  width: 30px; height: 30px;
  border-radius: 50%;
  display: grid; place-items: center;
  font-weight: 700;
  background: var(--surface-3);
  color: var(--muted-2);
  border: 2px solid var(--border-strong);
  transition: all .2s ease;
  z-index: 1;
}
.step b { display: block; font-size: 14px; }
.step small { color: var(--muted); font-size: 12px; }
.step.active {
  border-color: var(--brand);
  box-shadow: 0 6px 18px rgba(37,99,235,.18);
  transform: translateY(-1px);
}
.step.active .dot {
  background: linear-gradient(180deg, #3b82f6, var(--brand-d));
  color: #fff; border-color: transparent;
  box-shadow: 0 3px 10px rgba(37,99,235,.4);
}
.step.done .dot {
  background: var(--accent); border-color: transparent; color: #fff;
}
.step.done .dot::after { content: "✓"; }
.step.done .dot { font-size: 0; }
.step.done .dot::after { font-size: 15px; }

/* ---------- layout ---------- */
.layout {
  max-width: 1240px;
  margin: 18px auto 0;
  padding: 0 24px;
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(340px, 1fr);
  gap: 18px;
  align-items: stretch;   /* 两列等高，消除单侧空白 */
}
.col { display: flex; flex-direction: column; gap: 18px; min-width: 0; }

/* 弹性卡片：在列内自动填充剩余高度，使两列始终等高、无死白 */
.card.grow {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}
.card h2 {
  margin: 0 0 12px; font-size: 16px; font-weight: 700;
  display: flex; align-items: center; gap: 8px;
}
.card h2 .ic { width: 18px; height: 18px; color: var(--brand); flex: 0 0 auto; }
.hint { margin: 0 0 12px; font-size: 12.5px; color: var(--muted); }

/* ---------- dropzone ---------- */
.dropzone {
  border-style: dashed;
  border-color: var(--border-strong);
  text-align: center;
  padding: 26px 18px;
  cursor: pointer;
  transition: border-color .2s ease, background .2s ease, transform .15s ease;
}
.dropzone:hover { border-color: var(--brand); background: #f0f7ff; }
.dropzone.over { border-color: var(--brand); background: #e3f0ff; transform: scale(1.005); }
.dz-inner { display: flex; flex-direction: column; align-items: center; gap: 6px; pointer-events: none; }
.dz-icon { color: var(--brand-2); }
.dz-icon svg { width: 36px; height: 36px; }
.dz-text { font-weight: 600; }
.dz-formats { font-size: 12px; color: var(--muted-2); }
.audio-name {
  margin-top: 12px;
  font-size: 13px;
  color: var(--brand-d);
  font-weight: 600;
  word-break: break-all;
}

/* ---------- player / waveform ---------- */
.player { padding-bottom: 14px; }
.waveform {
  width: 100%;
  height: 140px;
  display: block;
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  border: 1px solid var(--border);
  cursor: pointer;
}
.karaoke {
  min-height: 30px;
  margin: 12px 4px 4px;
  font-size: 20px;
  font-weight: 700;
  color: var(--brand-d);
  text-align: center;
  letter-spacing: .5px;
  transition: opacity .25s ease;
}
.karaoke:empty { opacity: 0; }
.transport {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 8px;
  flex-wrap: wrap;
}
.btn.play { min-width: 92px; font-weight: 700; }
.time {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
}
.time .sep { margin: 0 4px; color: var(--muted-2); }
.seek { flex: 1; min-width: 120px; accent-color: var(--brand); cursor: pointer; }
.speed { font-size: 13px; color: var(--muted); display: flex; align-items: center; gap: 6px; }
.speed select {
  font-family: var(--font);
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  padding: 5px 8px;
  background: var(--surface);
}

/* ---------- status ---------- */
.status-line {
  font-size: 13.5px;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-left: 3px solid var(--brand);
  border-radius: 10px;
  padding: 10px 12px;
}

/* ---------- tools ---------- */
.tools { display: flex; flex-wrap: wrap; gap: 12px; align-items: flex-end; }
.tool { display: flex; flex-direction: column; gap: 5px; font-size: 12px; color: var(--muted); }
.tool .num {
  width: 90px; padding: 7px 9px;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  font-family: var(--mono);
  background: var(--surface);
}

/* ---------- lyrics / lines ---------- */
.lyrics-in {
  width: 100%;
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  padding: 10px;
  font-family: var(--mono);
  font-size: 13px;
  resize: vertical;
  background: var(--surface);
}
.lyrics-in:focus, .lrc-out:focus, .meta-grid input:focus, .tool .num:focus {
  outline: none;
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(37,99,235,.15);
}
.lyrics-in { min-height: 150px; }
#btn-build { margin-top: 12px; }

.stat { margin-left: auto; font-size: 13px; font-weight: 400; color: var(--muted); }
.stat b { color: var(--brand-d); }

.progress {
  height: 8px;
  background: var(--surface-3);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 12px;
}
.progress .bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), #38bdf8);
  border-radius: 999px;
  transition: width .3s ease;
}

.lines-list {
  flex: 1 1 auto;          /* 填充卡片剩余高度 */
  min-height: 240px;
  max-height: 62vh;        /* 超长歌词时内部滚动，避免页面过高 */
  overflow-y: auto;
  border: 1px solid var(--border);
  border-radius: 10px;
}
/* 弹性卡片内的歌词输入框也随列高伸展 */
.card.grow > .lyrics-in { flex: 1 1 auto; min-height: 150px; max-height: 46vh; }
.lines-empty {
  padding: 28px 18px;
  text-align: center;
  color: var(--muted-2);
  font-size: 13px;
}
.line-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  border-left: 3px solid transparent;
  transition: background .12s ease, border-color .12s ease;
}
.line-row:last-child { border-bottom: none; }
.line-row:hover { background: var(--surface-2); }
.line-row.focused { background: #eaf1ff; border-left-color: var(--brand); }
.line-row.active { background: #effaf8; border-left-color: var(--accent); }
.line-row.blank { opacity: .55; }
.line-row .ts {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 13px;
  min-width: 92px;
  padding: 6px 8px;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  background: var(--surface);
  color: var(--muted);
  cursor: pointer;
  transition: all .12s ease;
}
.line-row .ts:hover { border-color: var(--brand); color: var(--brand-d); }
.line-row .ts.stamped {
  background: linear-gradient(180deg, #e6faf6, #d3f4ee);
  border-color: #a7e8dc;
  color: var(--accent-d);
  font-weight: 700;
}
.lidx { flex: 0 0 22px; color: var(--muted-2); font-size: 12px; text-align: right; }
.ltxt { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.line-row.active .ltxt { color: var(--accent-d); font-weight: 700; }
.actions { flex: 0 0 auto; display: flex; gap: 4px; }
.mini {
  font-family: var(--mono);
  font-size: 12px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  border-radius: 7px;
  padding: 4px 7px;
  cursor: pointer;
  color: var(--muted);
  transition: all .12s ease;
}
.mini:hover { border-color: var(--brand); color: var(--brand-d); }
.mini.del:hover { border-color: var(--danger); color: var(--danger); }

/* ---------- meta / export ---------- */
.meta-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
}
.meta-grid label { display: flex; flex-direction: column; gap: 4px; font-size: 12px; color: var(--muted); }
.meta-grid input {
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  padding: 7px 9px;
  font-family: var(--font);
  background: var(--surface);
}
.opt-row { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; margin-bottom: 12px; font-size: 13px; color: var(--muted); }
.opt-row select { border: 1px solid var(--border-strong); border-radius: 8px; padding: 5px 8px; background: var(--surface); }
.chk { display: flex; align-items: center; gap: 6px; cursor: pointer; }
.chk input { accent-color: var(--brand); }
.export-row { display: flex; gap: 10px; margin-bottom: 12px; }
.lrc-out {
  width: 100%;
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  padding: 10px;
  font-family: var(--mono);
  font-size: 13px;
  resize: vertical;
  min-height: 120px;
  background: var(--surface-2);
}

/* ---------- footer ---------- */
.foot {
  max-width: 1240px;
  margin: 22px auto 0;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 12.5px;
  color: var(--muted);
}
.foot .shortcuts kbd { margin: 0 2px; }
.foot a { color: var(--accent); text-decoration: none; font-weight: 600; }
.foot a:hover { text-decoration: underline; }

/* ---------- responsive ---------- */
@media (max-width: 880px) {
  .layout { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr 1fr; }
  .step::after { display: none; }
}
@media (max-width: 520px) {
  .steps { grid-template-columns: 1fr; }
  .meta-grid { grid-template-columns: 1fr; }
  .topbar { flex-direction: column; align-items: flex-start; }
}