:root {
  color-scheme: dark;
  --bg0: #050714;
  --bg1: #0f1a3d;
  --accent: #26ffe6;
  --warn: #ff4f70;
  --text: #f4f6ff;
  --muted: #98a3cc;
}

* { box-sizing: border-box; }

html,
body {
  margin: 0;
  min-height: 100%;
  background: radial-gradient(circle at top, #121d46 0%, var(--bg0) 55%);
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--text);
}

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

.app-shell {
  width: min(980px, 100%);
  display: grid;
  gap: 12px;
  position: relative;
}

.hud {
  display: grid;
  gap: 8px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.hud-item {
  border: 1px solid rgba(38, 255, 230, 0.32);
  background: rgba(8, 12, 30, 0.85);
  border-radius: 12px;
  padding: 8px 10px;
  display: grid;
}

.hud-item span {
  font-size: 12px;
  color: var(--muted);
}

.hud-item strong {
  font-size: 18px;
  letter-spacing: 0.4px;
}

#gameCanvas {
  width: 100%;
  height: min(72vh, 680px);
  border: 1px solid rgba(38, 255, 230, 0.4);
  border-radius: 14px;
  background: linear-gradient(180deg, #090d23 0%, #050714 100%);
  touch-action: none;
}

.overlay {
  position: absolute;
  inset: 56px 12px 12px;
  background: rgba(3, 5, 18, 0.84);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 14px;
  display: grid;
  place-content: center;
  text-align: center;
  padding: 22px;
  gap: 12px;
  backdrop-filter: blur(5px);
}

.overlay h1 {
  margin: 0;
  font-size: clamp(28px, 5vw, 44px);
  color: var(--accent);
}

.overlay p {
  margin: 0;
  color: #d9e2ff;
}

.overlay ul {
  margin: 0;
  padding: 0;
  list-style: none;
  color: var(--muted);
  font-size: 14px;
  display: grid;
  gap: 6px;
}

.overlay button {
  border: 0;
  border-radius: 999px;
  background: linear-gradient(135deg, #1ed5ff, #3affb2);
  color: #00101d;
  font-weight: 700;
  font-size: 16px;
  padding: 12px 20px;
  cursor: pointer;
  justify-self: center;
}

.overlay.hidden {
  display: none;
}

.toast {
  position: absolute;
  bottom: 18px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(11, 20, 44, 0.9);
  border: 1px solid rgba(38, 255, 230, 0.35);
  border-radius: 999px;
  padding: 8px 14px;
  color: var(--accent);
  font-weight: 700;
}

@media (max-width: 720px) {
  .hud {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .overlay {
    inset: 108px 8px 8px;
  }
}