#1 화면배치하기 ( overflow의 사용)DOCTYPE html> 화면 배치 header{background-color: aqua; height: 100px;} nav{background-color: yellow; float:left; width: 25%;} section{background-color:moccasin; float: left; width: 50%;} aside{background-color: tomato; float:left; width: 25%;} footer{background-color: gray; clear: both; height: 200px;} .d1{ border:1px solid red; padding:10px; margin:5px; float:left; width:20..