:root {
  --bg: #070b28;
  --panel: rgba(19, 18, 59, .82);
  --panel-border: rgba(255,255,255,.16);
  --accent: #8d4dff;
  --accent-2: #ffcf24;
  --text: #fff;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; background: radial-gradient(circle at top, #1b2aa8, var(--bg)); color: var(--text); font-family: Arial, Helvetica, sans-serif; }
body { overflow-x: hidden; }

.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(320px, 520px) minmax(280px, 360px);
  gap: 22px;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.game-frame {
  width: min(100%, 520px);
  aspect-ratio: 9 / 16;
  border-radius: 28px;
  overflow: hidden;
  box-shadow: 0 32px 100px rgba(0,0,0,.45), inset 0 0 0 1px rgba(255,255,255,.18);
  background: #10103a;
}

#game, #game canvas { width: 100% !important; height: 100% !important; display: block; }

.demo-panel {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 24px;
  padding: 22px;
  box-shadow: 0 24px 70px rgba(0,0,0,.28);
  backdrop-filter: blur(10px);
}

.demo-panel h1 { margin: 0 0 8px; font-size: 28px; }
.demo-panel p { margin: 0 0 16px; line-height: 1.45; color: rgba(255,255,255,.82); }
.panel-group { display: grid; gap: 10px; margin-top: 18px; }
.panel-group h2 { margin: 0; font-size: 14px; letter-spacing: .08em; text-transform: uppercase; color: var(--accent-2); }
.setting-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 14px;
  align-items: center;
  padding: 12px 14px;
  border: 1px solid rgba(255,255,255,.16);
  border-radius: 14px;
  background: rgba(255,255,255,.08);
}
.setting-row strong {
  display: block;
  font-size: 14px;
  color: #ffffff;
}
.setting-row small {
  display: block;
  margin-top: 4px;
  line-height: 1.35;
  color: rgba(255,255,255,.72);
}
.setting-row input {
  width: 22px;
  height: 22px;
  accent-color: var(--accent-2);
  cursor: pointer;
}
button {
  appearance: none;
  border: 0;
  border-radius: 14px;
  padding: 12px 14px;
  color: white;
  font-weight: 800;
  text-align: left;
  background: linear-gradient(135deg, #6e45ff, #b943ff);
  box-shadow: 0 10px 22px rgba(0,0,0,.22);
  cursor: pointer;
}
button:hover { transform: translateY(-1px); filter: brightness(1.08); }
button:active { transform: translateY(1px) scale(.99); }
button.danger { background: linear-gradient(135deg, #ff3d66, #ff8a2a); }
.hint { margin-top: 18px !important; font-size: 13px; }

@media (max-width: 920px) {
  .app-shell { grid-template-columns: 1fr; padding: 14px; }
  .game-frame { margin-inline: auto; max-height: 82vh; }
}