Comment by onedognight

Except it's not just CSS; It uses Javascript to update a CSS transform element

    -moz-transform: rotate(%ddeg)

whereas the OP uses CSS animations.

    .hand {
        -moz-animation-direction: normal;
        -moz-animation-duration: 60000ms;
        -moz-animation-iteration-count: infinite;
        -moz-animation-name: spin;
        -moz-animation-timing-function: linear;
    }
    .hour.hand {
        -moz-animation: 0s ease 0s normal none 1 none;
    }
    .minutes.hand {
        -moz-animation: 0s ease 0s normal none 1 none;
    }