<div>
  <iframe src="https://codepen.io/claarman/full/EaGNKj/"></iframe>
</div>

<div>
  <iframe src="https://codepen.io/claarman/full/KwJdja"></iframe>
</div>

<div>
  <iframe src="https://codepen.io/claarman/full/XJxqmG"></iframe>
</div>

<div>
  <iframe src="https://codepen.io/claarman/full/vEQKOb"></iframe>
</div>

<span>click here to get out of fullscreen mode</span>
iframe {
  border: 0;
  width: 100%;
  height: 100%;
}

body {
  position: absolute;
  margin: 0px;
  font-family: verdana;
  font-size: 12px;
  background-color: #ddd;
}

span {
  position: fixed;
  top: 0px;
  left: 0px;
  right: 0px;
  color: white;
  background-color: #444;
  text-align: center;
  overflow: hidden;
  display: inline;
  vertical-align: middle;
  border: 1px solid #666;
  border-width: 0 0 1px 0;
  z-index: 3;
  padding: 8px;
  transition: all .3s;
  cursor: pointer;
  &:hover {
    background-color: #333;
  }
}

div {
  z-index: 1;
  position: fixed;
  top: 32px;
  left: 0;
  bottom: 0;
  right: 0;
  background-color: #333;
  transform: scale(0.15);
  transition: transform .3s, margin .1s;
  transition-delay: .01s;
  box-shadow: 0px 0px 40px rgba(0,0,0,.5);
  cursor: pointer;
  &:before {
    transition: opacity .3s;
    position: absolute;
    content: '';
    top: 0;
    left: 0;
    z-index: 2;
    background-color: black;
    opacity: .2;
    width: 100%;
    height: 100%;
  }
  &:hover {
    transform: scale(0.16);
    box-shadow: 0px 0px 40px black;
    &:before {
      opacity: 0;
    }
  }
  &:nth-child(1) {
    top: -60%;
    left: -70%;
  }
  &:nth-child(2) {
    top: -60%;
    left: -21%;
  }
  &:nth-child(3) {
    top: -60%;
    right: -21%;
  }
  
  &:nth-child(4) {
    top: -60%;
    right: -70%;
  }
  &.active {
    z-index: 2;
    transform: scale(1);
    margin: 0;
    top: 32px;
    left: 0;
    bottom: 0;
    right: 0;
    &:before {
      display: none;
    }
  }
}
View Compiled


$('div').on('click', function() {
  $(this).addClass('active');
});

$('span').on('click', function(e) {
  $('div').removeClass('active');    
});
Run Pen

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. //cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js