:root {
  color-scheme: dark;
  --bg: #08111f;
  --panel: rgba(13, 24, 43, 0.84);
  --panel-2: rgba(19, 33, 57, 0.78);
  --text: #e8f1ff;
  --muted: #98abc7;
  --line: rgba(148, 163, 184, 0.24);
  --accent: #60a5fa;
  --accent-2: #34d399;
  --warn: #fbbf24;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, "Segoe UI", Arial, "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 16% 12%, rgba(96, 165, 250, 0.20), transparent 28%),
    radial-gradient(circle at 84% 8%, rgba(52, 211, 153, 0.14), transparent 26%),
    linear-gradient(135deg, #040917 0%, var(--bg) 55%, #101827 100%);
}
.shell {
  min-height: 100vh;
  display: grid;
  align-items: start;
  grid-template-columns: minmax(300px, 360px) 1fr;
  gap: 18px;
  padding: 18px;
}
.panel, .glass {
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--panel);
  box-shadow: 0 24px 70px rgba(0,0,0,.32);
  backdrop-filter: blur(18px);
}
.panel { padding: 22px; overflow: auto; max-height: calc(100vh - 36px); }
h1 { margin: 0 0 10px; font-size: 30px; letter-spacing: -.03em; }
.lead { margin: 0 0 20px; color: var(--muted); line-height: 1.6; }
.card {
  padding: 16px;
  margin: 14px 0;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: var(--panel-2);
}
.card h2 { margin: 0 0 12px; font-size: 16px; }
label { display: grid; gap: 7px; margin: 12px 0; color: var(--muted); font-size: 13px; }
input[type="range"] { width: 100%; }
button {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(8, 17, 31, 0.9);
  color: var(--text);
  padding: 10px 12px;
  cursor: pointer;
  font-weight: 700;
  transition: transform .15s ease, border-color .15s ease;
}
button:hover { transform: translateY(-1px); border-color: rgba(96, 165, 250, 0.7); }
button.primary { background: linear-gradient(135deg, #2563eb, #1d4ed8); border: 0; }
button.ghost { background: rgba(15, 23, 42, 0.72); }
.actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.value-row { display: flex; justify-content: space-between; gap: 10px; }
.value-row output { color: var(--text); font-variant-numeric: tabular-nums; }
.hint { margin: 12px 0 0; color: var(--muted); font-size: 12px; line-height: 1.55; }
.stats-grid { display: grid; grid-template-columns: repeat(2,1fr); gap: 10px; }
.stat {
  padding: 14px;
  border-radius: 14px;
  background: rgba(8,17,31,.62);
  border: 1px solid var(--line);
}
.stat span { display: block; color: var(--muted); font-size: 12px; margin-bottom: 6px; }
.stat strong { font-size: 20px; }
.stage { display: grid; grid-template-rows: 520px 270px; gap: 18px; min-width: 0; align-content: start; }
.viz-card, .mini-viz { padding: 18px; }
.section-head { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-bottom: 12px; }
.section-head h2, .section-head h3 { margin: 0; }
.section-head p { margin: 4px 0 0; color: var(--muted); font-size: 13px; }
.section-head.small { margin-bottom: 10px; }
.pill {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(52,211,153,.14);
  color: var(--accent-2);
  border: 1px solid rgba(52,211,153,.24);
  font-size: 12px;
  font-weight: 700;
}
canvas {
  width: 100%;
  display: block;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(5,11,24,.94), rgba(6,13,26,.82));
}
#oscillatorCanvas { height: 430px; min-height: 430px; }
.viz-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; min-width: 0; }
#historyCanvas, #spectrumCanvas { height: 190px; }
@media (max-width: 980px) {
  .shell { grid-template-columns: 1fr; }
  .stage { grid-template-rows: auto auto; }
  .viz-grid { grid-template-columns: 1fr; }
  #oscillatorCanvas { height: 340px; min-height: 340px; }
}