#AU {
    position: absolute;
    top: 0;
    color: transparent;
}

#AC {
    position: absolute;
    color: transparent;
}

#AU:focus,
#AC:focus {
    color: black;
}

.skip-link {
    position: absolute;
    background-color: #FFF;
    color: #000;
    font-weight: bold;
    left: -999px; /* 隱藏連結 */
}

.skip-link:focus {
    left: 310px; /* 當連結獲得焦點時顯示 */
    padding: 8px;
    margin: 3px;
    z-index: 1050;
}