--description--

When elements are positioned to overlap (i.e. using position: absolute | relative | fixed | sticky), the element coming later in the HTML markup will, by default, appear on the top of the other elements. However, the z-index property can specify the order of how elements are stacked on top of one another. It must be an integer (i.e. a whole number and not a decimal), and higher values for the z-index property of an element move it higher in the stack than those with lower values.

--instructions--

Add a z-index property to the element with the class name of first (the red rectangle) and set it to a value of 2 so it covers the other element (blue rectangle).

--hints--

The element with class first should have a z-index value of 2.

assert($('.first').css('z-index') == '2');

--seed--

--seed-contents--

<style>
  div {
    width: 60%;
    height: 200px;
    margin-top: 20px;
  }

  .first {
    background-color: red;
    position: absolute;

  }
  .second {
    background-color: blue;
    position: absolute;
    left: 40px;
    top: 50px;
    z-index: 1;
  }
</style>

<div class="first"></div>
<div class="second"></div>

--solutions--

<style>
  div {
    width: 60%;
    height: 200px;
    margin-top: 20px;
  }

  .first {
    background-color: red;
    position: absolute;
    z-index: 2;
  }
  .second {
    background-color: blue;
    position: absolute;
    left: 40px;
    top: 50px;
    z-index: 1;
  }
</style>
<div class="first"></div>
<div class="second"></div>