css play button on image

1.more_video_img {
2  position: relative;
3}
4
5.playBtn {
6  position: absolute;
7  width: 40px;
8  height: 40px;
9  left: 50%;
10  top: 50%;
11  margin-left: -20px; /*half of the width */
12  margin-top: -20px; /*half of the height */
13}