body { background: linear-gradient(160deg, #2c3142 0%, #1a1f2e 60%, #0e1218 100%); }
body.dark { background: linear-gradient(160deg, #161a26 0%, #08090e 100%); }

#game-canvas {
  display: block;
  width: 100%;
  max-width: min(95vw, 440px);
  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: #1a1f2e;
}
body.dark #game-canvas { background: #0d1118; }

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