<div id="wrap">
  <div id="header"></div>
  <div id="nav"></div>
  <div id="aside"></div>
  <div id="section"></div>
  <div id="footer"></div>
</div>
* {
  margin: 0;
}
body {
  background-color: #FFF3E0;
}
#wrap{
  width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
}
#header{
  width: 100%;
  height: 100px;
  background-color: #FFE0B2;
}
#nav{
  width: 100%;
  height: 100px;
  background-color: #FFCC80;
}
#aside{
  width: 30%;
  height: 780px;
  background-color: #FFB74D;
}
#section{
  width: 70%;
  height: 780px;
  background-color: #FFA726;
}
#footer{
  width: 100%;
  height: 100px;
  background-color: #FF9800;
}
@media(max-width: 1220px){
  #wrap {
    width: 96%;
    height: 100%;
  }

}
@media(max-width: 768px){
  #wrap {
    width: 100%;
    height: 100%;
  }
}
@media(max-width: 480px){
  #aside {
    width: 100%;
    height: 300px;
  }
  #section {
    width: 100%;
    height: 480px;
  }
}

External CSS

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External JavaScript

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