* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
main {
    background-color: lightblue;
}
.container {
    width: 100%;
    height: 100vh;
}
.container .row .board div{
    height: 125px;
    cursor: pointer;
}
.hide {
    display: none;
}
@media screen and (max-width:576px) {
    .container .row .board div{
        height: 80px;
    }
}