body {
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    position: relative;
    background-color: goldenrod;
}

main {
    width: 80vw;
    height: 70vh;
    overflow: hidden;
    margin: 15vh auto;
    background-color: gold;
    display: flex;
    flex-direction: column;
    justify-content: center;
    
}

.grid-cell-hover {
    background-color: silver;
}

button {
    position: relative;
    display: inline-block;
    text-align: center;
}