How to change the order of elements without changing the html code?

Question

These are 3 inline-block and elements which means that they will be ordered next to each other.

Here is a fiddle to view everything live: https://jsfiddle.net/8mdm8eox/

.wrapper {
  background: #fff;
  width: 100%
}

.firstElement,
.secondElement,
.thirdElement {
  display: inline-block;
  width: calc(100%/3)
}

.firstElement {
  background: #000;
  color: #fff
}

.secondElement {
  background: grey
}

.thirdElement {
  background: #ddd
}

@media (max-width: 767px) {}

<div class="wrapper">
  <div class="firstElement">First Element</div>
  <div class="secondElement">Second Element</div>
  <div class="thirdElement">Third Element</div>
</div>

So here is what I want , I want when the screen width is 767px or less:

@media (max-width: 767px){}

The first two elements are ordered vertically and the third one is ordered horizontally with the two other elements, So that they become like:

   _______________    ________________
   |First Element|    |ٍ              |
   _______________    |              |  
                      |Third Element |
   ________________   |              |
   |Second Element|   |              |
   _________________  _______________

Don't worry about the third element , The text will be broken , I just want the first two elements to look like that without changing the html.

Answer 1

There are various ways to re-order your elements without altering the HTML.

CSS flexbox provides the order property. However, flex may not be a good option for you since you want one element to span two rows. The problems you may encounter are discussed here:

• Make a div span two rows in a grid
• Is it possible for flex items to align tightly to the items above them?

CSS grid layout, however, offers many good solutions to your problem. The order property is also available here, but it's not necessary.

Here's one solution using the grid-template-areas property.

.wrapper {
  display: grid;
  grid-gap: 5px;
  grid-template-areas: "first second third";
}

.firstElement {
  grid-area: first;
  background: #000;
  color: #fff
}

.secondElement {
  grid-area: second;
  background: grey
}

.thirdElement {
  grid-area: third;
  background: #ddd
}

@media (max-width: 767px) {
  .wrapper {
    grid-template-areas: "first third" 
                         "second third";
  }

<div class="wrapper">
  <div class="firstElement">First Element</div>
  <div class="secondElement">Second Element</div>
  <div class="thirdElement">Third Element</div>
</div>

jsFiddle demo

Browser support for CSS Grid.

Answer 2

You need to use flex-wrap on the .wrapper and order on children.

.wrapper {
  max-width: calc(100%/2);  //Just to keep your original width intact
  display: flex;
  flex-wrap:wrap;
}

.firstElement, .secondElement, .thirdElement{
    min-width:50%; //This will force your width to 50% of your wrapper class
}
.firstElement{ order: 1;}
.secondElement{ order: 2;}
.thirdElement{ order: 3;}

.wrapper {
  background: #fff;
  max-width: calc(100%/2);
  display: flex;
  flex-wrap: wrap;
}

.firstElement,
.secondElement,
.thirdElement {
  display: inline-block;
  min-width: 50%
}

.firstElement {
  background: #000;
  color: #fff;
  order: 1;
}

.secondElement {
  background: grey;
  order: 3;
}

.thirdElement {
  background: #ddd;
  order: 2;
}

@media (max-width: 767px) {}

<div class="wrapper">
  <div class="firstElement">First Element</div>
  <div class="secondElement">Second Element</div>
  <div class="thirdElement">Third Element</div>
</div>