@font-face {
    font-family: 'source-serif';
    src:  url('source-serif/source-serif-4-var.woff2') format('woff2'),
        url('source-serif/source-serif-4-var.ttf') format('truetype');
    font-weight: 100 900;
    font-style: normal;
    font-display: swap;
}