.ttt-container { height: 100%; position: relative; width: 100%; }

.ttt-cell {
  align-items: center;
  aspect-ratio: 1;
  background: #f3f3f3;
  border-right: 3px solid #aaa;
  border-bottom: 3px solid #aaa;
  cursor: pointer;
  display: flex;
  font-size: 48px;
  justify-content: center;
  transition: scale .09s ease-out;
  width: 100%;
}

.ttt-cell:nth-child(3n)  { border-right: none; }
.ttt-cell:nth-child(n+7) { border-bottom: none; }

.ttt-cell svg { height: 60%; width: 60%; overflow: visible; }

.ttt-cell.disabled { pointer-events: none; }

.winning-line-overlay {
  height: 100%;
  left: 0;
  opacity: .25;
  pointer-events: none;
  position: absolute;
  top: 0;
  width: 100%;
  z-index: 10;
}

.winning-line-svg { height: 100%; width: 100%; }