acknowledge.css

#contribute {
    width: 100%;
    padding: 30px 0;
}
#team,
#team li {
    list-style-type: none;
    margin: 0;
    padding: 0;
}

#team {
    margin: 0 -10px;
    overflow: hidden;
    clear: both;
}

#team li {
    width: 140px;
    height: 140px;
    margin: 10px;
    float: left;
    border-radius: 120px;
    background: rgba(255,255,255,0.5);
}

#team li a img {
    width: 140px;
    height: 140px;
    border-radius: 120px;
    opacity: .7;
    -webkit-filter: grayscale(100%);
    -moz-filter: grayscale(100%);
    -o-filter: grayscale(100%);
    -ms-filter: grayscale(100%);
    filter: grayscale(100%);
}

#team li a:hover img {
    opacity: 1;
    -webkit-filter: grayscale(100%);
    -moz-filter: grayscale(100%);
    -o-filter: grayscale(100%);
    -ms-filter: grayscale(100%);
    filter: grayscale(100%);
}

#team li a {
    position: relative;
    display: block;
}

#team li a:after {
    width: 140px;
    height: 80px;
    display: block;
    position: absolute;
    top: 0;
    content: attr(title);
    background: rgb(208, 209, 104);
    background: rgba(208, 209, 104, 0.90);
    border-radius: 140px;
    text-align: center;
    padding: 60px 0px 0;

    font-size: 10px;
    font-weight: bold;
    text-transform: uppercase;
    color: #434B5C;
    color: rgba(67,75,92,0.8);

    box-shadow: 0 0 0 1px rgba(208, 209, 104, 0.90), inset 0 0 0 1px rgba(208, 209, 104, 0.90);

    opacity: 0;
}

.wf-active #team li a:after {
    font-size: 13px;
    line-height: 1;
    font-weight: 700;
}

#team li a:hover:after {
    opacity: 1;
}

/* Transitions for Contributors block */

#team li a img,
#team li a:hover img {
    -webkit-transition: all .3s ease-out;
    -moz-transition: all .3s ease-out;
    -o-transition: all .3s ease-out;
    -ms-transition: all .3s ease-out;
    transition: all .3s ease-out;
}

#team li a:after,
#team li a:hover:after, {
    -webkit-transition: opacity .3s ease-out;
    -moz-transition: opacity .3s ease-out;
    -o-transition: opacity .3s ease-out;
    -ms-transition: opacity .3s ease-out;
    transition: opacity .3s ease-out;
}