How can i have view upper side if i am writing code in down side

Question

This is my HTML and CSS. I want a result like the image posted below. I have the number 1 on the top, and 2 on the bottom according to my code, but without changing the HTML, I want to have the result show 2 on the top and 1 on the bottom. I am trying to use CSS grid of bootstrap.

<style>
    .grid-container {
      grid-template-columns: footer header;
      grid-gap: 10px;
      background-color: #2196F3;
      padding: 10px;
    }
    .item1 { grid-area: footer; }
    .item2 { grid-area: header; }
    
.grid-container > div {
  background-color: rgba(255, 255, 255, 0.8);
  text-align: center;
  padding: 20px 0;
  font-size: 30px;
}
</style>   

 <div class="grid-container">
      <div class="item1">1</div>
      <div class="item2">2</div>
 </div>

result -:

but i want the result

HTML should not be changed. I want change in only CSS.

Answer 1

You can achieve this by using flex-wrap:wrap-reverse.

.grid-container {
  grid-template-columns: footer header;
  grid-gap: 10px;
  background-color: #2196F3;
  padding: 10px;
  flex-wrap: wrap-reverse;
  display: flex;
  width:calc(100% - 20px);
}

.item1 {
  grid-area: footer;
}

.item2 {
  grid-area: header;
}

.grid-container>div {
  background-color: rgba(255, 255, 255, 0.8);
  text-align: center;
  padding: 20px 0;
  font-size: 30px;
  flex-basis: 100%;
}

<div class="grid-container">
  <div class="item1">1</div>
  <div class="item2">2</div>
</div>