CodePen

HTML

            
              <div id="box">
  
  <div id="overlay">
    <span id="plus">+</span>
  </div>
  
</div>
            
          
!

CSS

            
              body    {  background:#e7e7e7;}
#box    {  width:300px;
           height:200px;
           box-shadow:inset 1px 1px 40px 0 rgba(0,0,0,.45);
          border-bottom:2px solid #fff;
          border-right:2px solid #fff;
          margin:5% auto 0 auto; 
          background:url(http://ianfarb.com/wp-content/uploads/2013/10/nicholas-hodag.jpg);
  background-size:cover;
border-radius:5px;
overflow:hidden;}

#overlay    {  background:rgba(0,0,0,.75);
               text-align:center;
               padding:45px 0 66px 0;
               opacity:0;
               -webkit-transition: opacity .25s ease;
-moz-transition: opacity .25s ease;}

#box:hover #overlay {
               opacity:1;}

#plus       {  font-family:Helvetica;
               font-weight:900;
               color:rgba(255,255,255,.85);
               font-size:96px;}


            
          
!
? ?
? ?
Must be a valid URL.
+ add another resource
via CSS Lint

JS

            
              
            
          
!
Must be a valid URL.
+ add another resource
via JS Hint
Loading ..................