:root {
  --bg: #0b0f1a;
  --panel: #121829;
  --text: #e8ecf1;
  --muted: #9aa6b2;
  --accent: #6cf1e6;
  --good: #8df59a;
  --bad: #ff8181;
  --warn: #ffd47a;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: radial-gradient(1200px 800px at 50% 20%, #0f1630 0%, var(--bg) 60%);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, Noto Sans, "Apple Color Emoji", "Segoe UI Emoji";
}

.wrap {
  display: grid;
  grid-template-rows: auto 1fr auto;
  height: 100%;
}

.topbar {
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 16px;
  align-items: center;
  padding: 10px 16px;
  background: linear-gradient(180deg, rgba(255,255,255,0.05), rgba(0,0,0,0.1));
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.title { font-weight: 700; letter-spacing: 0.5px; }

.hud { display: flex; gap: 14px; font-variant-numeric: tabular-nums; }
.hud span { color: var(--muted); }
.hud span strong { color: var(--text); }

.controls { display: flex; gap: 8px; }
label.level-label { color: var(--muted); font-size: 0.9rem; align-self: center; }
button {
  background: var(--panel);
  color: var(--text);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 6px;
  padding: 6px 10px;
  cursor: pointer;
}
button:hover { filter: brightness(1.1); }

select#level {
  background: var(--panel);
  color: var(--text);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 6px;
  padding: 6px 8px;
}

.stage {
  display: grid;
  place-items: center;
  padding: 16px;
}

canvas {
  background: linear-gradient(180deg, #02040a 0%, #0b1226 35%, #060a15 100%);
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 10px 30px rgba(0,0,0,0.4), inset 0 0 80px rgba(108,241,230,0.05);
  max-width: min(95vw, 1000px);
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: var(--text);
  text-align: center;
  padding: 16px;
  pointer-events: none;
}
.overlay.hidden { display: none; }

.overlay .panel {
  background: rgba(10,14,28,0.75);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 12px;
  padding: 18px 20px;
  max-width: 580px;
  backdrop-filter: blur(6px);
}
.overlay h1 { margin: 0 0 8px; }
.overlay p { margin: 8px 0; color: var(--muted); }

.help {
  color: var(--muted);
  text-align: center;
  padding: 8px 12px 14px;
}