:root {
  --bg0: #0a0b10;
  --bg1: #11121a;
  --panel: rgba(255, 255, 255, 0.06);
  --panel2: rgba(255, 255, 255, 0.08);
  --line: rgba(255, 255, 255, 0.12);
  --txt: rgba(255, 255, 255, 0.92);
  --muted: rgba(255, 255, 255, 0.68);
  --accent: #7c3aed;
  --accent2: #a78bfa;
  --good: #22c55e;
  --bad: #ef4444;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  background: radial-gradient(1200px 800px at 50% -10%, rgba(124, 58, 237, 0.35), transparent 55%),
    radial-gradient(900px 700px at 70% 10%, rgba(34, 197, 94, 0.18), transparent 55%),
    linear-gradient(180deg, var(--bg1), var(--bg0));
  color: var(--txt);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Arial, "Noto Sans Thai", sans-serif;
  overflow: hidden;
}

#app {
  position: fixed;
  inset: 0;
}

canvas#game {
  width: 100vw;
  height: 100vh;
  display: block;
  background: transparent;
  touch-action: none;
}

#hud {
  position: fixed;
  inset: 0;
  pointer-events: none;
  display: grid;
  place-items: center;
}

#hud > button {
  pointer-events: auto;
  appearance: none;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.14), rgba(255, 255, 255, 0.06));
  color: var(--txt);
  padding: 12px 16px;
  border-radius: 14px;
  font-weight: 800;
  letter-spacing: 0.2px;
  cursor: pointer;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(10px);
}

#hud > button:hover {
  border-color: rgba(255, 255, 255, 0.18);
}

#hud > button:active {
  transform: translateY(1px) scale(0.99);
}

#start-btn,
#restart-btn {
  width: min(280px, 82vw);
  border: none;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  box-shadow: 0 16px 40px rgba(124, 58, 237, 0.35);
}

#restart-btn {
  display: none;
}

#fs-btn {
  position: fixed;
  right: max(14px, env(safe-area-inset-right));
  top: max(14px, env(safe-area-inset-top));
  padding: 10px 12px;
  border-radius: 12px;
  font-weight: 800;
  opacity: 0.92;
}