* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

fieldset {
    border: 0;
}

ul, ol {
    list-style: none;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Chess board */

h1 {
    margin: 16px 0;
}

.box {
    background-color: #a6adbb;
    padding: 20px;
    width: fit-content;
    border-radius: 8px;
}

.board {
    box-sizing: border-box;
    border: 6px solid;
    color: black;
}

.row {
    text-align: center;
    font-size: 0;
}

.row span {
    width: 100px;
    height: 50px;
    display: inline-block;
    vertical-align: middle;
    font-size: 30px;
    text-transform: uppercase;
}

.row .num {
    display: block;
    width: 30px;
}

.col {
    display: inline-block;
    vertical-align: top;
    font-size: 30px;
}

.col div {
    width: 50px;
    height: 100px;
    position: relative;
    top: 25px;
}

.field {
    box-sizing: border-box;
    border: 4px solid;
    display: inline-block;
    font-size: 0;
}

.field div {
    height: 100px;
    width: 100px;
    display: inline-block;
}
  
.field div:nth-child(2n) {
    background: black;
}