<p>some text...</p>
<input id="zoom" type="checkbox">
<label for="zoom" class="container">
  <img alt="kitten" src="http://placekitten.com/g/600/300"/>
</label>
<p>some another text</p>

* {
  margin:0 auto;
}
html, body{
  width:100%;
  height:100%;
  text-align:justify;
}
p{
  display:block;
  height:25%;
  overflow:hidden;
}
label + p {
  position:absolute;
  top:260px;
  height:auto;
}
#zoom{
  display:none;
}
input + .container {
  position:absolute;
  z-index:9999;
  top:25%;
  right:0;
  left:0;
  bottom:0;
  width:300px;
  height:150px;
  text-align:center;
  cursor:pointer;
  display:block;
  -webkit-transition: height .4s, width .4s, background-color .4s;
  transition: height .4s, width .4s, background-color .4s, top .4s;
  background-color: rgba(0,0,0,0)
}
input:checked + .container {
  position:fixed;
  top:0%;
  right:0;
  left:0;
  bottom:0;
  width:100%;
  height:100%;
  background-color: rgba(0,0,0,0.8);
}
input + .container img{
  max-width: 100% !important;
  max-height: 100% !important;
  position: relative;
  top: 50%;
  -webkit-transform: translateY(-50%);
  -ms-transform: translateY(-50%);
  transform: translateY(-50%);
}