Why not padding-top: 50% ? The height is to big for an embeb cover. Please try and see how it look with 50%. In my opinion looks better...

#es .es-stream-embed__cover {

    text-align: center;

    border-radius: 3px 3px 0 0;

    background-color: #f0f0f0;

    position: relative;

    padding-top: 50%;

    overflow: hidden;

}

Thank you