.reversi-wrap {
	max-width: 880px;
}

.reversi-board {
	display: grid;
	grid-template-columns: repeat(8, 1fr);
	gap: 4px;
	background: #14532d;
	padding: 6px;
	border-radius: 10px;
	box-shadow: 0 8px 24px rgba(0, 0, 0, .35);
	aspect-ratio: 1;
}

.reversi-cell {
	background: #198754;
	border: 1px solid rgba(255, 255, 255, .22);
	border-radius: 6px;
	padding: 0;
	position: relative;
	cursor: pointer;
}

.reversi-cell::before {
	content: "";
	display: block;
	padding-top: 100%;
}

.reversi-cell:disabled {
	cursor: default;
	opacity: .85;
}

.disc {
	position: absolute;
	inset: 12%;
	border-radius: 50%;
}

.disc.black {
	background: radial-gradient(circle at 30% 30%, #444, #0f0f0f 60%);
	box-shadow: inset 0 0 8px rgba(255, 255, 255, .15);
}

.disc.white {
	background: radial-gradient(circle at 30% 30%, #fff, #d8d8d8 62%);
	box-shadow: inset 0 0 8px rgba(0, 0, 0, .18);
}

.valid-dot {
	position: absolute;
	inset: 38%;
	border-radius: 50%;
	background: rgba(255, 193, 7, .9);
}