:root {
  --bg: #0a0d12;
  --bg-grid: #11161f;
  --fg: #e6ecf3;
  --fg-muted: #8b96a5;
  --fg-dim: #566271;
  --accent: #00e5a0;
  --border: #1f2630;
  --border-strong: #2a3340;

  --font-ui: 'Geist', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, Menlo, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-ui);
  -webkit-user-select: none;
  user-select: none;
  touch-action: none;
}

canvas {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  display: block;
  cursor: grab;
}
canvas:active { cursor: grabbing; }

.hud-top, .hud-bottom {
  position: fixed;
  left: 0;
  right: 0;
  z-index: 10;
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  pointer-events: none;
}
.hud-top { top: 0; justify-content: space-between; }
.hud-bottom { bottom: 0; justify-content: center; }

.hud-top > *, .hud-bottom > * { pointer-events: auto; }

.back, .reset {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 0.5rem 0.85rem;
  color: var(--fg-muted);
  background: rgba(10, 13, 18, 0.6);
  border: 1px solid var(--border);
  border-radius: 4px;
  text-decoration: none;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: all 0.2s ease;
  cursor: pointer;
}
.back:hover, .reset:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.title {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.2em;
  color: var(--fg-dim);
  font-weight: 500;
}

.hint {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--fg-muted);
  padding: 0.5rem 1rem;
  background: rgba(10, 13, 18, 0.6);
  border: 1px solid var(--border);
  border-radius: 4px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  text-align: center;
  letter-spacing: 0.02em;
}
.kbd {
  color: var(--accent);
  font-weight: 500;
}

.tilt-btn {
  position: fixed;
  right: 1.25rem;
  bottom: 4.5rem;
  z-index: 20;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.6rem 1rem;
  color: var(--accent);
  background: rgba(10, 13, 18, 0.8);
  border: 1px solid var(--accent);
  border-radius: 4px;
  cursor: pointer;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

@media (max-width: 560px) {
  .hint { font-size: 0.62rem; }
  .title { display: none; }
}