style.css

@font-face {
    font-display: swap;
    /* Check https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/font-display for other options. */
    font-family: 'Fira Code';
    font-style: normal;
    font-weight: 400;
    src: url('./fonts/fira-code-v22-latin-regular.woff2') format('woff2');
    /* Chrome 36+, Opera 23+, Firefox 39+, Safari 12+, iOS 10+ */
}

/* fira-code-600 - latin */
@font-face {
    font-display: swap;
    /* Check https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/font-display for other options. */
    font-family: 'Fira Code';
    font-style: normal;
    font-weight: 600;
    src: url('./fonts/fira-code-v22-latin-600.woff2') format('woff2');
    /* Chrome 36+, Opera 23+, Firefox 39+, Safari 12+, iOS 10+ */
}

html, body {
    font-family: 'Fira Code', Mono;
    height: 100%;
    width: 100%;
    margin: 0;
    padding: 0;
}

#grid {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    grid-template-rows: 1fr auto;
    min-height: 100vh;

    & > * {
        width: 100%;
        height: 100%;
    }
}

#clock {
    font-size: 4rem;
    height: 6rem;
    font-weight: 600;
    color: white;
    background-color: black;
    grid-column-start: 1;
    grid-column-end: 4;
    text-align: center;
}