:root {
  --bg: #0f172a;
  --card: #1e293b;
  --text: #f1f5f9;
  --muted: #94a3b8;
  --accent: #22d3ee;
  --good: #4ade80;
  --warn: #fbbf24;
}
* { box-sizing: border-box; margin: 0; }
html, body { height: 100%; }
body {
  background: var(--bg); color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}
body.app { overflow: hidden; }
.hidden { display: none !important; }
.overlay {
  position: fixed; inset: 0; z-index: 10; background: var(--bg);
  display: flex; flex-direction: column; justify-content: center; gap: 16px;
  padding: 24px 16px; max-width: 560px; margin: 0 auto;
}
h1 { font-size: 2rem; color: var(--accent); }
.tagline, .fineprint, label { color: var(--muted); }
.fineprint { font-size: 0.85rem; }
input {
  font-size: 1.1rem; padding: 12px; border-radius: 10px;
  border: 1px solid var(--muted); background: var(--card); color: var(--text);
}
button {
  font-size: 1.1rem; padding: 14px; border-radius: 10px; border: none;
  background: var(--card); color: var(--text); cursor: pointer;
}
button.primary { background: var(--accent); color: #083344; font-weight: 700; }
#stage { position: fixed; inset: 0; }
#stage canvas { display: block; }
#btn-exit {
  position: fixed; top: 10px; left: 10px; z-index: 5;
  padding: 8px 14px; font-size: 0.9rem; opacity: 0.75;
}
#rotate { align-items: center; text-align: center; }