#btn {
        width: 35px;/*按钮的宽度*/
        height: 35px;/*按钮的高度*/
        background: url("static/images/music.png") no-repeat;
        background-size: 100% 100%;
        -webkit-background-size: 100% 100%;
        -moz-background-size: 100% 100%;
        -ms-background-size: 100% 100%;
        -o-background-size: 100% 100%;
        position: fixed;
        top: 3.1866666666666665rem;
        right: 1rem;
        z-index: 1000;
    }
    
    #div_btn_inner{ /*按钮部分内层，用于定位*/
            color:white; 
            text-shadow:1px 1px 1px #000;            
            width: 500px;
            padding-left: 430px;
        }