connect-four.css

.cf {
    background-color: #fcfcfc;
    position: relative;
}
    .cf .player-info {
        position: relative;
        top:0;
        z-index:10;
        text-align: center;
        font-size: 2em;
        font-family: Arial, sans-serif;
        font-weight: bold;
        opacity: 0.5;
    }

    .cf .player-info.gameover {
        padding:55px 20px;
        background: #339933;
        color: #fff;
        opacity: 0.8;
    }

    .cf .place {
        position: absolute;
        z-index:5;
        top: 0;
        left: 0;
        width: 40;
        height: 40;
        border: 2px solid #99ccff;
        border-radius: 50%;
    }
    .cf .place.empty {
    }
    .cf.player1 .place.empty:hover {
        background-color: #ffcccc;
    }
    .cf.player2 .place.empty:hover {
        background-color: #ffffcc;
    }
    .cf .disk {
        border-radius: 50%;
    }
    .cf .disk.red {
        background: #ff6666;
        background: -moz-radial-gradient(center, ellipse cover,  #ff3019 0%, #cf0404 100%); /* FF3.6-15 */
        background: -webkit-radial-gradient(center, ellipse cover,  #ff3019 0%,#cf0404 100%); /* Chrome10-25,Safari5.1-6 */
        background: radial-gradient(ellipse at center,  #ff3019 0%,#cf0404 100%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
        filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#ff3019', endColorstr='#cf0404',GradientType=1 ); /* IE6-9 fallback on horizontal gradient */
    }
    .cf .disk.yellow {
        background: #ffff66;
        background: -moz-radial-gradient(center, ellipse cover,  #f1e767 0%, #feb645 100%); /* FF3.6-15 */
        background: -webkit-radial-gradient(center, ellipse cover,  #f1e767 0%,#feb645 100%); /* Chrome10-25,Safari5.1-6 */
        background: radial-gradient(ellipse at center,  #f1e767 0%,#feb645 100%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
        filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#f1e767', endColorstr='#feb645',GradientType=1 ); /* IE6-9 fallback on horizontal gradient */
    }