css整理

font-size:12px;
line-height:22px;
font-family:Arial,Helvetica,sans-serif;

/*优化*/
font:12px/22px Arial,Helvetica,sans-serif;

background-color:#eee;
background-image:url(background.gif);
background-repeat:no-repeat;
background-attachment:fixed;
background-position:0 0;
background-size:50px 50px;
/*优化  background-size*/
background:#f00 url(background.gif) no-repeat fixed 0 0/50px 50px;

/*针对低版本浏览器none无效*/
border:none;border:0\9;  

/*激活虚线问题*/
a:active,a:focus{outline:none;  star:expression(this.onFocus=this.blur());}