Replace "Add File" icon

background: linear-gradient(to bottom, #ffffff 0, #f2f2f2 100%);
border: 1px solid #cccccc;
border-radius: 0.25em;
color: #222222;
font-weight:bold;

+icon
font awesome: fa-plus 
color: #39c943;

mouse over:
background-color: #ededed;

focus:
-webkit-box-shadow: 0px 0px 16px 0px rgba(133,188,255,0.84);
-moz-box-shadow: 0px 0px 16px 0px rgba(133,188,255,0.84);
box-shadow: 0px 0px 16px 0px rgba(133,188,255,0.84);