/*returnTop*/
p#back-to-top{ 
position:fixed;
z-index: 9999; 
bottom:10px; 
right:10px; 
} 
p#back-to-top a{ 
text-align:center; 
text-decoration:none; 
color:#d1d1d1; 
display:block; 
width:40px; 
/*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:color 1s; 
-webkit-transition:color 1s; 
-o-transition:color 1s; 
} 
p#back-to-top a:hover{ 
color:#979797; 
} 
p#back-to-top a span{ 
background:url(../images/totop.png) no-repeat;
display: block;
display:block; 
height:40px; 
width:40px; 
/*使用CSS3中的transition属性给<span>标签背景颜色添加渐变效果*/
-moz-transition:background 1s; 
-webkit-transition:background 1s; 
-o-transition:background 1s; 
}
#back-to-top a:hover span{ 
background:url(../images/totop.png) no-repeat; 
}