* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
    overflow: hidden;
    width: 100dvw;
    height: 100dvh;
    font-size: 24px;
    user-select: none;
}

main {
    width: 100dvw;
    height: 100dvh;
    padding: 1rem;
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 0.5rem;

    button {
        font-size: 10vmin;
        cursor: pointer;
        width: 100%;
        height: 100%;

        &[disabled] {
            pointer-events: none;
        }
    }
}

body > button {    
    width: 100dvw;
    height: 100dvh;
    font-size: 80vmin;
}