html, body {
    margin: 0;
    width: 100%;
    height: 100%;
    background-color: black;
}

#cam-link {
    display: block;
    width: 100vw;
    height: 100vh;
    text-decoration: none;
}

#cam-img {
    width: 99%;
    height: 99%;
    object-fit: contain;   /* or cover */
}