/* Tetris — responsive static site, no external assets. */
:root {
  --bg: #0e0f12;
  --panel: #161a22;
  --panel-2: #1d2230;
  --text: #e6e9ef;
  --muted: #8a93a6;
  --accent: #5cc8ff;
  --border: #2a3040;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.5);
  --gap: 16px;
  --radius: 8px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  min-height: 100vh;
  -webkit-text-size-adjust: 100%;
}

.app {
  max-width: 720px;
  margin: 0 auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: var(--gap);
}

.app-header h1 {
  margin: 0;
  font-size: 1.5rem;
  letter-spacing: 0.1em;
  text-align: center;
  color: var(--accent);
}

.play-area {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--gap);
  align-items: start;
}

@media (max-width: 520px) {
  .play-area {
    grid-template-columns: 1fr;
    justify-items: center;
  }
  .side-panel {
    width: 100%;
    max-width: 320px;
  }
}

.board-wrap {
  position: relative;
  background: #000;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  /* Canvas internal resolution: 300x600, scaled to fit small screens. */
  width: min(90vw, 300px);
  aspect-ratio: 1 / 2;
}
#board {
  display: block;
  width: 100%;
  height: 100%;
  image-rendering: pixelated;
}

.overlay[hidden] { display: none; }

.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.7);
  color: var(--text);
  font-size: 1.5rem;
  text-align: center;
  border-radius: var(--radius);
}

.side-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--panel);
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  min-width: 160px;
}

.stat {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
}
.stat-label {
  color: var(--muted);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.stat-value {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
}

.next {
  display: flex;
  flex-direction: column;
  gap: 6px;
  align-items: center;
}
#next {
  background: #000;
  border: 1px solid var(--border);
  border-radius: 4px;
  width: 100%;
  max-width: 120px;
  height: auto;
  aspect-ratio: 1 / 1;
}

.actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.actions button {
  grid-column: span 1;
}
.actions button:nth-child(1) { grid-column: 1 / 2; }
.actions button:nth-child(2) { grid-column: 2 / 3; }
.actions button:nth-child(3) { grid-column: 1 / 3; }

button {
  font: inherit;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  cursor: pointer;
  transition: background 0.1s ease, transform 0.05s ease;
  min-height: 44px;
  min-width: 44px;
}
button:hover { background: #232a3b; }
button:active { transform: translateY(1px); }
button:disabled { opacity: 0.5; cursor: not-allowed; }

.mobile-controls {
  display: grid;
  gap: 8px;
}
.mobile-controls .row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}
.mobile-controls button {
  font-size: 1.25rem;
  min-height: 48px;
}

.app-footer {
  text-align: center;
  color: var(--muted);
}
.app-footer small { font-size: 0.8rem; }

@media (max-width: 520px) {
  .app { padding: 8px; gap: 10px; }
  .play-area { grid-template-columns: auto minmax(0, 1fr); gap: 8px; align-items: start; }
  .board-wrap { width: min(55vw, calc((100dvh - 240px) / 2)); }
  .side-panel { min-width: 0; max-width: none; padding: 8px; gap: 8px; }
  .stat-label { font-size: 0.66rem; letter-spacing: 0; }
  .stat-value { font-size: 1rem; }
  #next { max-width: 72px; }
  .actions { grid-template-columns: 1fr; gap: 5px; width: 100%; }
  .actions button:nth-child(n) { grid-column: 1; font-size: 0.78rem; padding: 8px 2px; }
  .mobile-controls { touch-action: manipulation; }
  .app-footer small { font-size: 0.65rem; }
}