/*右侧悬浮导航*/
.float{width:111px;height:200px;position:fixed; right:0;top: 500px; _position:absolute;overflow:hidden; z-index:50}/*left50%确保页面中间，左边距515大于页面内容的一半，确保在内容整体右侧外*/
.float a{display:block;text-indent:-9999px;overflow:hidden;height:42px; background:url("https://www.glennisbrowne.com/images/right_nav.png") no-repeat;-webkit-transition:background 0.2s ease}
.float .an_1:hover{background-position:-111px 0}
.float .an_2{background-position:-222px 0}
.float .an_2:hover{background-position:-333px 0}
.float .an_3{background-position:-444px 0}
.float .an_3:hover{background-position:-555px 0}