:root {
  color-scheme: dark;
  --bg: #0f172a;
  --panel: #1e293b;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #22c55e;
  --accent-strong: #16a34a;
  --border: #334155;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at top, #1e293b 0%, #0f172a 55%);
  color: var(--text);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

.app {
  width: min(960px, 100% - 2rem);
  margin: 1.5rem auto 2rem;
}

.header h1 {
  margin: 0;
  font-size: clamp(1.5rem, 4vw, 2rem);
}

.header p {
  margin: 0.35rem 0 1rem;
  color: var(--muted);
}

.panel {
  padding: 1rem;
  background: color-mix(in srgb, var(--panel) 85%, black 15%);
  border: 1px solid var(--border);
  border-radius: 14px;
}

.game-frame {
  width: 100%;
  min-height: 360px;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  background: black;
}

.controls {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

button {
  border: 1px solid var(--border);
  background: #0b1224;
  color: var(--text);
  padding: 0.55rem 0.8rem;
  border-radius: 8px;
  cursor: pointer;
}

button:hover {
  border-color: var(--accent);
}

button:active {
  background: #060b17;
}

.keys {
  margin-top: 1rem;
  padding: 0.9rem 1rem;
  background: color-mix(in srgb, var(--panel) 88%, black 12%);
  border: 1px solid var(--border);
  border-radius: 14px;
}

.keys h2 {
  margin: 0 0 0.55rem;
  font-size: 1.1rem;
}

.keys ul {
  margin: 0;
  padding-left: 1.15rem;
  line-height: 1.55;
}

.status {
  margin-top: 0.85rem;
  color: var(--accent);
}

@media (max-width: 640px) {
  .game-frame {
    min-height: 260px;
  }
}