.flv-player {
    width: 100%;
    max-width: 600px;
    height: 400px;
    margin-bottom: 10px;
    display: flex;
}
@media  (min-width: 1200px) {
  .flv-player {
    margin-left: 10%;
    margin-right: 10%;
  }
}
#flv-flowplayer {
    width: 100%;
    height:400px;
}