style.css

body {
     font-family: "Trebuchet MS", "Helvetica", "Arial",  "Verdana", "sans-serif";
     font-size: 62.5%;
}

.board-row {
	width: 100%;
	float: left;
}

.board-square {
    width: 2.5vw;
    height: 2.5vw;
	float: left;
    border: 1px solid;
}

.board-open {
	background-color: white;
}

.board-blocker {
	background-color: black;
	border-radius: 25%;
}

.board-empty {
	background-color: gray;
}

.board-goal {
	background-color: purple;
}

.board-start {
	background-color: pink;
}

.board-player1 {
	background-color: red;
	border-radius: 50%;
    text-align: center;
    font-size: 18px;
}
.board-player2 {
	background-color: green;
	border-radius: 50%;
    text-align: center;
    font-size: 18px;
}
.board-player3 {
	background-color: yellow;
	border-radius: 50%;
    text-align: center;
    font-size: 18px;
}
.board-player4 {
	background-color: blue;
	border-radius: 50%;
    text-align: center;
    font-size: 18px;	
}

.board {
	width: 100%;
}

.board-available {
	border: 1px;
	border-color: green;
}