html {
    width: 100%;
}

body {
    width: 100%;
}

.base {
    width: 100%;
    margin: 0 auto;
    text-align: center;
}

.chessboard {
    width: 330px;
    margin: 50px auto;
    border-collapse: collapse;
    overflow: hidden;
}

tr {
    padding: 0;
    margin: 0;
    height: 30px;
    text-align: center;
}

* {
    box-sizing: border-box;
}

td {
    margin: 0;
    padding: 0;
    width: 30px;
    height: 30px;
    border: solid 1px #E5E5E5;
}

tr:first-child td {
    border: none;
    border-bottom: solid 2px black;
}

tr:last-child td {
    border-bottom: solid 2px black;
}

td:nth-child(2) {
    border-left: solid 2px black;
}

td:last-child {
    border-right: solid 2px black;
}

.turnLeft {
    border-left: solid 10px blue;
}

.turnRight {
    border-right: solid 10px blue;
}

.forward {
    border-top: solid 10px blue;
}

.back {
    border-bottom: solid 10px blue;
}

.turnLeft, .turnRight, .forward, .back {
    background-color: red;
    transition: background 0.5s ease-out;
    width: 30px;
    height: 30px;
}