/* transitions.css */

a:link {
    transition: color 0.5s;
  }
  
  img {
    opacity: 0.25;
    transition: opacity 500ms;
    padding-top: 10px;
  }
  
  img:hover {
    opacity: 1;
  }

  /* challenge */

  figure {
    position: relative; 
  }

  figure img {
    position: absolute ;
    top: 0;
    left: 0 ;
  }

  figure .visible {
    opacity: 1;
  }

  figure .hidden {
    opacity: 0 ;
  }

  figure:hover .hidden{
    opacity: 1;
  }