<div id="wrap">
  <div id="header"></div>
  <div id="nav"></div>
  <div id="box">
    <div id="aside"></div>
    <div id="section"></div>
  </div>
  <div id="footer"></div>
</div>
* {
  margin: 0;
  padding: 0;
}
body {
  background-color: #FFF3E0;
}
#wrap {
  width: 1200px;
  margin: 0 auto; /* 블록구조를 가운데 정렬 */
}
#header {
  height : 100px;
  background-color: #FFE0B2;
}
#nav {
  height : 100px;
  background-color: #FFCC80;
}
#box {
  display: grid;
  grid-template-areas:
    "aside section"
    "aside section"
    ;
  grid-template-columns: 30% 70%;
  grid-template-rows: 780px 780px;
}
#aside {
  grid-area: aside;
  background-color: #FFB74D;
}
#section {
  grid-area: section;
  background-color: #FFA726;
}
#footer {
  height: 100px;
  background-color: #FF9800;
}
@media(max-width: 1220px){
  #wrap {
    width: 96%;
  }
}
@media(max-width: 768px){
  #wrap {
    width: 100%;
  }
}
@media(max-width: 480px){
  #wrap {
    width: 100%;
  }
  #box {
    display: grid;
    grid-template-areas:
      "aside"
      "section"
      ;
    grid-template-columns: 100%;
    grid-template-rows: 300px 480px;
  }
}

External CSS

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External JavaScript

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