header {
  -webkit-box-align: center;
      -ms-flex-align: center;
          align-items: center;
  background: #333;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  font-size: 18px;
  height: 100vh;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
  overflow: hidden;
  position: relative;
  text-align: center;
  -webkit-transform-style: preserve-3d;
          transform-style: preserve-3d;

  -webkit-perspective: 100px;

          perspective: 100px;
}

header:after {
  background: #F9FCFF;
  content: "";
  height: 40rem;
  left: -5%;
  position: absolute;
    right: -5%;
    top: 90%;
  -webkit-transform: rotateZ(-4deg);
          transform: rotateZ(-4deg);
  -webkit-transform-origin: 0 0;
          transform-origin: 0 0;
}

.header-title, .header-subtitle {
  color: #fff;
}

.header-subtitle {
  margin-bottom: 5rem;
  text-transform: uppercase;
}

.header-button {
  position: relative;
  -webkit-transform: translateZ(.1px);
          transform: translateZ(.1px);
  z-index: 10;
}