#game-canvas {
  display: block;
  width: 100%;
  max-width: 460px;
  height: auto;
  max-height: calc(100dvh - 140px);
  margin: 0 auto;
  cursor: pointer;
  touch-action: none;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  background: #1a2030;
}
body.dark #game-canvas { background: #0a0e16; }

.board-wrapper {
  display: flex;
  justify-content: center;
}