* { margin:0; padding:0; } .zhiti { width:900px; height:1000px; margin:auto; } .kaishi { width:100px; height:30px; border:2px solid yellowgreen; text-align:center; line-height:30px; float:left; margin-left:300px; } .tingzhi { width:100px; height:30px; border:2px solid yellowgreen; text-align:center; line-height:30px; float:right; margin-right:300px; background:red; } ul li { list-style:none; width:50px; height:50px; background:greenyellow; float:left; text-align:center; line-height:50px; margin-top:40px; margin-left:44px; } .bot { width:300px; height:30px; border:3px solid silver; position:absolute; bottom:560px; left:550px; }