* { box-sizing: border-box; } body {margin: 0;}body{margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;}*{box-sizing:border-box;}body{margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;}section{min-height:40px;}div.container{min-height:40px;}