css play button

gistfile1.txt

.channel__image:hover:before, .bxslider li a:hover:before {
    content: " ";
    border-radius: 50%;
    width: 50px;
    height: 50px;
    margin-left: -25px;
    margin-top: -25px;
    color: #000000;
    text-align: center;
    position: absolute;
    top: 60px;
    right: 50%;
    bottom: 50%;
    left: 50%;
    background: black;
    background: rgba(0, 0, 0, 0.75);
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000);
    -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000)";
    z-index: 2;
}
Pseudo ::after element
.bxslider li a:hover:after {
    border-top: 26px solid transparent;
    border-bottom: 26px solid transparent;
    border-left: 36px solid #9aca3b;
    top: 42%;
    margin-top: 0px;
    margin-left: 13px;
}
.channel__image:hover:after, .bxslider li a:hover:after {
    content: "";
    position: absolute;
    top: 60px;
    right: 50%;
    bottom: 50%;
    left: 50%;
    width: 0;
    height: 0;
    margin-top: -13px;
    margin-left: -6px;
    border-top: 13px solid transparent;
    border-bottom: 13px solid transparent;
    border-left: 18px solid #9aca3b;
    z-index: 3;