.audio {
    display: none;
    margin-top: 30px;
    opacity: 50%;
    height: 1.5em;
}

/* 针对触摸设备（如手机端）的样式 */
@media (hover: none) and (pointer: coarse) {
    .audio {
        opacity: 80%; /* 手机端透明度为80% */
        width: 40px;
    }
}
        
        
footer {
    display: block;
    position: absolute;
    bottom: 5%;
    text-align: center;
    width: 100%;
}

.footer_item {
    text-align: center;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
}

.footer_item > li {
    list-style-type: none;
    margin: 0 auto;
    height: 48px;
}

.footer_item svg {
    color: white;
    cursor: pointer;
    width:36px;
    height: 48px;
}

/*.footer_item svg:hover {*/
/*    color: #ff0;*/
/*}*/

.footer_item li > ul {
    background: gray;
    transition: all 0.4s ease;
    overflow: hidden;
    position: absolute;
    bottom: 30px;
    width: 120px;
    right: 33%;
    left: auto;
    padding: 0;
    border-radius: 2px;
}

.footer_item li > ul > li a{
    color: white;
    text-decoration: none;
    padding: 5px;
    display: block;
}

.footer_item li > ul > li + li {
    border-top:1px solid #eee;
}

.footer_item #languages_list li.active {
    font-weight: bold;
}