/* Tic Tac Toe board — the only custom CSS for this game (everything else is Bootstrap).
   The grid lines are drawn by the <td class="riga"> separator cells. */
.board {
	border-collapse: collapse;
	margin: 0 auto;
}
.board td {
	text-align: center;
	border: none;
	padding: 10px;
	font-size: 40px;
	width: 50px;
	height: 50px;
	background-color: #fff;
	color: #212529;
}
.board td.f4 {
	border: 7px solid purple; /* segna la terna vincente */
}
.board td.riga {
	background-color: purple;
	width: 25px;
	height: 25px;
	border: 7px solid #000;
}
.board td.O { color: green; }
.board td.X { color: blue; }