.first-block:after{
    content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  -webkit-transform-origin: 100% 0;
  -ms-transform-origin: 100% 0;
  transform-origin: 100% 0;
  -webkit-transform: skew(-30deg);
  -ms-transform: skew(-30deg);
  transform: skew(-30deg);
  z-index: -1;
  background: rgba(172,226,226,0.44);
}