.video-t{
  list-style: none;
  padding: 0;
  text-align: center;
}
.video-t li{
  background-color: #ddd;
  background-size: cover;
  background-position: center center;
  display: inline-block;
  width: 230px;
  height: 128px;
  opacity: 0.5;
  cursor: pointer;
  margin: 10px
}

.video-t li:hover{
  opacity: 1;
}

.video-o{
  position: fixed; 
  width: 100%; 
  height: 100%; 
  background: #fff;
  top: 0;
  left: 0;
}

.video-o .frame{
  width: 560px;
  height: 315px;
  position: relative;
  margin: 20px auto;
}