<style>
	
		*, ::before, ::after { 
			box-sizing: border-box;
			margin: 0;
			padding: 0;
		}	
		
		html, body {
			height: 100%;			
			width: 100%;			
			background: #fff;
		}
						
		#box {
			left: calc((100% - 680px) / 2);
			top: calc((100% - 420px) / 2);
			position: absolute;
			width: 686px;
			height: 426px;
			border: 3px #660000 solid;
		}

</style>