skin.xml

<?xml version='1.0'?>
<a:skin xmlns:a="http://ajax.org/2005/aml">
<a:button name="btn-ungit-nav">
    <a:style><![CDATA[
        .btn-ungit-nav {
          height             : 24px;
          overflow           : hidden;
          cursor             : default;
          position           : relative;
          background-repeat:no-repeat;
          background-position: 0 0;
          -moz-user-select: -moz-none;
          -khtml-user-select : none;
          -webkit-user-select: none;
          -o-user-select: none;
          user-select        : none;
          
          background: url(images/toolbar.png) repeat-x 0 100px;
          border-radius: 3px;

          border: 1px solid transparent;
        }

        .btn-ungit-navOver {
          border-color: #010910;
        }

        .btn-ungit-navDown {
          background-position : 0 -36px;
          border-color: #010910;
        }

        .btn-ungit-nav .icon {
          width                 : 24px;
          height                : 23px;
          -webkit-border-radius : 3px;
          -moz-border-radius    : 3px;
          border-radius         : 3px;
          margin-left: 1px;
        }
        
        .btn-ungit-nav.close .icon {
            position: relative;
        }
        
        .btn-ungit-nav.close .icon:before {
          content: "\f00d";
          font-family: FontAwesome;
          color: #fff;
          left:6px;
          position:absolute;
          top:6px;
        }
        
        .btn-ungit-nav.refresh .icon {
            position: relative;
        }
        
        .btn-ungit-nav.refresh .icon:before {
          content: "\f021";
          font-family: FontAwesome;
          color: #fff;
          left:6px;
          position:absolute;
          top:6px;
        }
        
        .btn-ungit-nav.popup .icon {
            position: relative;
        }
        
        .btn-ungit-nav.popup .icon:before {
          content: "\f077";
          font-family: FontAwesome;
          color: #fff;
          left:6px;
          position:absolute;
          top:6px;
        }
    ]]></a:style>

     <a:presentation>
        <a:main caption="div" label="div" background="." icon="div">
            <div class="btn-ungit-nav">
                <div class="icon"/>
            </div>
        </a:main>
    </a:presentation>
</a:button>
</a:skin>