test.html

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
        <style>
            @font-face {
                font-family: LongLigaTest;
                src: url("./font-withliga.otf");
            }

            body,
            textarea {
                font-family: LongLigaTest, sans-serif;
                font-size: 48px;
            }
        </style>
    </head>
    <body>
        <div>
            this is an early test area, used for testing ligatures. firefox only supports ligatures
            up to 64, so it wasn't used very much.
        </div>
        <div>The quick brown fox jumped over the lazy dog.</div>
        <textarea></textarea>
    </body>
</html>