:root {
    padding: 1em;
    background-color: #000;
    color: #fff;
    display: flex;
    justify-content: center;
}

button {
    font-size: 2rem;
    padding: 0.25em 0.5em;
    border: 1px solid #fff;
    border-radius: 0.25em;
    background: #000;
    color: #fff;
    transition: all 0.125s ease-in-out;
}

button:hover {
    background: #222;
}

button:active {
    transform: scale(0.935);
}

@media screen and (max-width: 850px) {
    :root {
        padding: 3em;
    }

    button {
        font-size: 3rem;
        padding: 1em 2em;
    }

    button:hover {
        background: #000;
    }

    button:active {
        transform: scale(0.985);
    }
}