Use Media Queries to Create Responsive Layouts

Summary

CSS Grid can be an easy way to make your site more responsive by using media queries to rearrange grid areas, change dimensions of a grid, and rearrange the placement of items.

Final Code

<style>
  .item1 {
    background: LightSkyBlue;
    grid-area: header;
  }

  .item2 {
    background: LightSalmon;
    grid-area: advert;
  }

  .item3 {
    background: PaleTurquoise;
    grid-area: content;
  }

  .item4 {
    background: lightpink;
    grid-area: footer;
  }

  .container {
    font-size: 1.5em;
    min-height: 300px;
    width: 100%;
    background: LightGray;
    display: grid;
    grid-template-columns: 1fr;
    grid-template-rows: 50px auto 1fr auto;
    grid-gap: 10px;
    grid-template-areas:
      "header"
      "advert"
      "content"
      "footer";
  }

  @media (min-width: 300px){
    .container{
      grid-template-columns: auto 1fr;
      grid-template-rows: auto 1fr auto;
      grid-template-areas:
        "advert header"
        "advert content"
        "advert footer";
    }
  }

  @media (min-width: 400px){
    .container{
      grid-template-areas:
      /* Only change code below this line */
        "header header"
        "advert content"
        "footer footer";
      /* Only change code above this line */
    }
  }
</style>

<div class="container">
  <div class="item1">header</div>
  <div class="item2">advert</div>
  <div class="item3">content</div>
  <div class="item4">footer</div>
</div>