要想居中,首先得有宽度;
而span是inline,给width是不起作用的;要想起作用,得先让span变成inline-block;
span{display:inline-block;width:100px;text-align:center;}
设置文字居中显示的三句代码
middle-box{display:table;height:300px;border:1pxsolid#ff0000;width:400px;margin:0auto;position:relative;}
middle-inner{display:table-cell;vertical-align:middle;*position:absolute;*top:50%;*left:50%;width:100%;text-align:center;}//用了css的hack,对ie6,ie7的兼容
middle-innerp{position:relative;*top:-50%;*left:-50%;}