body {font-family:Verdana, sans-serif;}
        p {padding:20px 0;}

        #backtop {
	        position: fixed;
            left:auto;right: 20px;top:auto;bottom: 20px;
	        outline: none;
            overflow:hidden;
            color:#fff;
            text-align:center;
            background-color:rgba(49,79,96,0.84);
            height:40px;
            width:40px;
            line-height:40px;
            font-size:14px;
            border-radius:2px;
            cursor:pointer;
            transition:all 0.3s linear;
            z-index:999999;

            opacity:1;
            display:none;
        }
        #backtop:hover {
            background-color:#27CFC3;
        }
        #backtop.mcOut {
            opacity:0;
        }
/* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */