:root {
  --bg: #0b1220;
  --fg: #e5e7eb;
  --muted: #9aa2b1;
  --accent: #38bdf8;
  --accent-2: #a78bfa;
  --danger: #f472b6;
}
[data-theme="light"] {
  --bg: #f8fafc;
  --fg: #0b1220;
  --muted: #4b5563;
  --accent: #2563eb;
  --accent-2: #7c3aed;
  --danger: #db2777;
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  color: var(--fg);
  background: radial-gradient(1200px 600px at 50% 10%, #0f1a35 0%, var(--bg) 40%, #070b14 100%);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";
}
.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
}
.title { font-size: 18px; letter-spacing: 0.08em; opacity: 0.9; }
.tools { display: flex; gap: 10px; align-items: center; }
.btn { border: 1px solid rgba(255,255,255,0.12); background: transparent; color: var(--fg); padding: 8px 12px; border-radius: 10px; cursor: pointer; }
.btn:hover { border-color: rgba(255,255,255,0.25); }
.status { font-size: 12px; color: var(--muted); }

.stage { position: relative; width: 100%; height: calc(100% - 96px); display: grid; place-items: center; padding: 6px; }
#pulse-canvas { width: min(1100px, 96vw); height: min(700px, 70vh); border-radius: 18px; display: block; box-shadow: 0 0 40px rgba(84,135,255,0.18) inset, 0 40px 120px rgba(7,11,20,0.8); }
.hint { position: absolute; bottom: 16px; left: 50%; transform: translateX(-50%); font-size: 12px; color: var(--muted); }

.foot { text-align: center; padding: 12px; font-size: 12px; color: var(--muted); }

@media (max-width: 640px) {
  .title { font-size: 16px; }
  #pulse-canvas { height: min(600px, 68vh); }
}