.middle boom!

.middle{
  position: absolute;
  display: block;
  top: 50%;
  left: 50%;
  width: 100%;
  text-align: center;
  transform: translate(-50%,-50%);
  transform-origin: 50% 50%;
}

Play: http://jsbin.com/feguhapeha/1/edit?html,css,output