5.6: Z-index

The property z-index is used to assign positional layers to stacked or overlapping elements

• default value is zero(0)

• lower number = lower in the stack

<div class="wrapper">
  <figure class="box-1"></figure>
  <figure class="box-2"></figure>
  <figure class="box-3"></figure>
  <figure class="box-4"></figure>
  <figure class="box-5"></figure>
  <figure class="box-6"></figure>
  <figure class="box-7"></figure>
</div>

body {
  background: #eee;
}

.wrapper {
  position: absolute;
  background: white;
  width: 600px;
  height: 600px;
  top: 50%;
  left: 50%;
  margin-left: -300px;
  margin-top: -300px;
  -webkit-box-shadow: 0px 40px 60px -20px rgba(0, 0, 0, 0.2);
          box-shadow: 0px 40px 60px -20px rgba(0, 0, 0, 0.2);
}

.box-1 {
  position: absolute;
  width: 400px;
  height: 400px;
  background: rgba(199,21,133,1.0);
  top: 50%;
  left: 50%;
  margin-top: -200px;
  margin-left: -200px;
}

.box-2 {
  position: absolute;
  width: 200px;
  height: 200px;
  background: pink;
  top: 50%;
  left: 50%;
  margin-top: -100px;
  margin-left: -100px;
}

.box-3 {
  position: absolute;
  width: 180px;
  height: 180px;
  background:rgba(199,21,133,1.0)rgba(199,21,133,1.0);
  top: 50%;
  left: 50%;
  margin-top: -90px;
  margin-left: -90px;
}

.box-4 {
  position: absolute;
  width: 160px;
  height: 160px;
  background: white;
  top: 50%;
  left: 50%;
  margin-top: -80px;
  margin-left: -80px;
}

.box-5 {
  position: absolute;
  width: 140px;
  height: 140px;
  background: rgba(199,21,133,1.0);
  top: 50%;
  left: 50%;
  margin-top: -70px;
  margin-left: -70px;
  z-index: 20;
}

.box-6 {
  position: absolute;
  width: 120px;
  height: 120px;
  background: rgba(72,61,139,1.0);
  top: 50%;
  left: 50%;
  margin-top: -160px;
  margin-left: -160px;
  z-index: 50;
}

.box-7 {
  position: absolute;
  width: 100px;
  height: 100px;
  background: rgba(106,90,205,1.0);
  top: 50%;
  left: 50%;
  margin-top: -90px;
  margin-left: -90px;
  z-index: 100;
}