js+css实现回到顶部按钮（back to top）

 p#back-to-top{ position:fixed; bottom:100px; right:80px; } p#back-to-top a{ text-align:center; text-decoration:none; color:#d1d1d1; display:block; width:30px; /*使用CSS3中的transition属性给跳转链接中的文字添加渐变效果*/ -moz-transition:color1s; -webkit-transition:color1s; -o-transition:color1s; } p#back-to-top a:hover{ color:#979797; } p#back-to-top a span{ background:#d1d1d1 url(../images/arrow_up.png-600) no-repeat center center; border-radius:6px; display:block; height:30px; width:30px; margin-bottom:5px; /*使用CSS3中的transition属性给标签背景颜色添加渐变效果*/ -moz-transition:background1s; -webkit-transition:background1s; -o-transition:background1s; } #back-to-top a:hover span{ background:#979797 url(../images/arrow_up.png-600) no-repeat center center; }