Edit in JSFiddle

@import url(http://fonts.googleapis.com/css?family=Open+Sans:400,300);
@import url(http://fonts.googleapis.com/css?family=PT+Sans+Narrow);



.icon-boxes {
    width: 300px;
    height: 150px;
    border: 2px solid #f2f2f2;
    float: left;
    position: relative;
    left: 0;
    right: 0;
    bottom: 0;
    top: 0;
    padding: 40px 0px 0px 0px;
    margin: 0;
    background: #fff;
    line-height: 35px;
    text-align: center;
    overflow: hidden;
    transition: 0.3s;
    -webkit-transition: 0.3s;
    -moz-transition: 0.3s;
    -o-transition: 0.3s;
    -ms-transition: 0.3s;
}

.icon-boxes a {text-decoration: none !important;}

.icon-boxes a span{
    font-family: 'Open Sans';
    font-size: 15px;
    text-transform: uppercase;
    color: #000;
}

.icon-boxes a img {
    height: 48px;
    width: 48px;
}

.icon-boxes dl {
    opacity: 0;
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    top: 0;
    padding: 20px;
    margin: 0;
    line-height: 2.5; 
    color: white;
    border: 2px solid #f2f2f2;
    background: rgba(255, 206, 6, 0.98);
    transition: 0.3s;
    -webkit-transition: 0.3s;
    -moz-transition: 0.3s;
    -o-transition: 0.3s;
    -ms-transition: 0.3s;
}

.icon-boxes:hover dl {
    opacity: 1;
}

.icon-boxes dl dt {
    font-family: 'Open Sans';
    font-size: 15px;
    line-height: 18px;
    margin: 40px auto;
    text-align: center;
}

.icon-boxes dl dd {
    margin-left: 0;
}