:root {
  --bg: #14181f;
  --panel: #1d232d;
  --field: #0f1319;
  --line: #2c3441;
  --text: #e8ecf2;
  --muted: #9aa4b3;
  --accent: #f28c28;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.4 system-ui, -apple-system, "PingFang HK", "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
}

/* ---------- header ---------- */
.top {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
}
.brand { font-weight: 700; font-size: 18px; white-space: nowrap; }
.name {
  flex: 1 1 160px;
  min-width: 140px;
  padding: 7px 10px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--field);
  color: var(--text);
  font-size: 15px;
}
.top-btns { display: flex; gap: 6px; flex-wrap: wrap; }
.help-btn { min-width: 36px; padding: 7px 10px; }

button {
  cursor: pointer;
  padding: 7px 12px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #2a3240;
  color: var(--text);
  font-size: 14px;
  font-family: inherit;
  white-space: nowrap;
}
button:hover { background: #354054; }
button:disabled { opacity: .4; cursor: default; }
button.primary { background: var(--accent); border-color: var(--accent); color: #1a0e00; font-weight: 700; }
button.primary:hover { background: #ffa04a; }
button.danger { background: #4a2323; border-color: #6b2c2c; }
button.danger:hover { background: #5e2b2b; }

/* ---------- layout ---------- */
.main {
  flex: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 12px;
  padding: 12px;
  min-height: 0;
}
.court-area {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  min-height: 0;
  height: calc(100dvh - 78px);
}
canvas#court {
  border-radius: 10px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, .5);
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
  display: block;
}

.panel {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 0;
}

/* ---------- playback ---------- */
.play-bar { display: flex; align-items: center; gap: 8px; }
.play-bar input[type=range] { flex: 1; min-width: 60px; accent-color: var(--accent); }
.play-bar button { min-width: 44px; }
.time { font-variant-numeric: tabular-nums; color: var(--muted); white-space: nowrap; font-size: 13px; }

.opts { display: flex; gap: 14px; flex-wrap: wrap; font-size: 14px; color: var(--muted); }
.opts label { display: inline-flex; align-items: center; gap: 4px; }
.opts input[type=checkbox] { accent-color: var(--accent); }
.opts select {
  background: var(--field); color: var(--text); border: 1px solid var(--line);
  border-radius: 6px; padding: 3px 4px; font-size: 13px;
}

/* ---------- keyframes ---------- */
.kf-tools { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.count { color: var(--muted); font-size: 14px; margin-right: auto; white-space: nowrap; }

.kf-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  overflow: auto;
  align-content: flex-start;
  flex: 1;
  min-height: 0;
  padding: 2px;
}
.kf {
  width: 72px;
  flex: 0 0 auto;
  border: 2px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  padding: 4px;
  cursor: pointer;
  text-align: center;
  font-size: 12px;
}
.kf:hover { border-color: #4a5668; }
.kf.sel { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(242, 140, 40, .35); }
.kf .thumb { width: 60px; height: 108px; display: block; margin: 0 auto; border-radius: 4px; }
.kf-idx { font-weight: 700; margin-top: 3px; }
.kf-dur { color: var(--muted); }
.kf-dur input {
  width: 44px; padding: 2px 3px; font-size: 12px; border-radius: 4px;
  border: 1px solid var(--line); background: var(--field); color: var(--text);
}

/* ---------- help + modal ---------- */
.help, .modal {
  position: fixed; inset: 0; z-index: 50;
  background: rgba(0, 0, 0, .6);
  display: flex; align-items: center; justify-content: center;
  padding: 16px;
}
.help-box, .modal-box {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px 22px;
  max-width: 520px;
  width: 100%;
  box-shadow: 0 20px 60px rgba(0, 0, 0, .6);
}
.help-box h2 { margin: 0 0 10px; font-size: 18px; }
.help-box ul { margin: 0 0 14px; padding-left: 20px; }
.help-box li { margin: 6px 0; }
.modal-box { text-align: center; }
.modal-title { font-weight: 700; margin-bottom: 12px; }
.bar { height: 10px; background: var(--field); border-radius: 5px; overflow: hidden; margin-bottom: 8px; }
.bar > div { height: 100%; width: 0; background: var(--accent); transition: width .15s; }
.muted { color: var(--muted); font-size: 13px; margin-bottom: 12px; }

/* ---------- mobile ---------- */
@media (max-width: 900px) {
  .main { grid-template-columns: 1fr; padding: 8px; }
  .court-area { height: auto; }
  .kf-list { flex-wrap: nowrap; overflow-x: auto; padding-bottom: 6px; }
  .top { gap: 8px; }
  .brand { font-size: 16px; flex: 1; }
  .name { flex-basis: 100%; }
  .top-btns { flex-basis: 100%; }
  .top-btns button { flex: 1; padding: 8px 4px; font-size: 14px; }
}