* { margin:0; padding:0; } #box { width:500px; height:250px; background:#f2f2f2; border:1px #ccc solid; border-radius:3px; position:absolute; left:calc(50% - 250px); top:calc(50% - 150px); } .boxHeader { height:45px; line-height:45px; border-bottom:1px #ccc solid; } .title { padding:0 15px; color:#333; float:left; } .close { padding:0 15px; color:#ccc; font-size:20px; float:right; cursor:pointer; } .boxCont { padding:25px 15px; font-size:14px; color:#666; text-align:center; }