Code nút back top

1. Thêm đoạn: <div>  <a class="uptop" href="javascript:scroll(0,0)"> Top </a> sau </div> và trước</body>


2. Thêm Ðoạn:
 .uptop {
    background: url("https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrtcbQj8QHR_Yc8V_3DJWpsZf2XXA8WejXerN_h9LzaqTfK5aOMrlcqSq9of_OPluUzGhq1R01fQs0NHIOsEMgZu2VI-LW1toxlVqJCuVuon9yKaUbT9PUxCsPvxJUcHkvX4qCo86zQ7YV/s1600/up.png") no-repeat scroll -69px top transparent;
    bottom: 10px;
    display: block;
    height: 56px;
    overflow: hidden;
    position: fixed;
    right: 42px;
    text-indent: -999px;
    width: 42px;
}
Vào trước </style> (tru?c </head>

Good Luck!
[ONE TEAM ONE DREAM]