#top_button {
    color: #a9a9a9;
    text-align: center;
    line-height: 64px;
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: 100px;
    height: 100px;
    background-color: #fafafa;
    border: 1px solid #a9a9a9;
    border-radius: 10px;
    border-color: rgba(0, 0, 0, 0.2);
    opacity: .6;
    cursor: pointer;
    z-index: 10;
    /*display: none;*/
    /*transform: translate3d(0,120px,0);*/
    /*-moz-transition: all .15s ease-out;*/
    /*-webkit-transition: all .15s ease-out;*/
    /*-o-transition: all .15s ease-out;*/
    /*transition: all 0.15s ease-out;*/
    -ms-transform: translate(0,120px);
    -webkit-transform: translate3d(0,160px,0);
    transform: translate3d(12px,160px,0);
    -webkit-transition: all .25s cubic-bezier(.215,.61,.355,1);
    -moz-transition: all .25s cubic-bezier(.215,.61,.355,1);
    transition: all .25s cubic-bezier(.215,.61,.355,1);
    /*淡入淡出*/
}

#top_button:hover {
    opacity: 1;
    -moz-transition: all .15s ease-out;
    -webkit-transition: all .15s ease-out;
    -o-transition: all .15s ease-out;
    transition: all 0.15s ease-out;
    /*淡入淡出*/
}