.embed-responsive {
    position: relative;
    display: block;
    width: 100%;
    padding: 0;
    overflow: hidden;
}

    .embed-responsive::before {
        display: block;
        content: "";
    }

.embed-responsive-16by9::before {
    padding-top: 56.25%; /* 16:9 aspect ratio */
}

.embed-responsive-item {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    width: 100%;
    height: 100%;
    border: 0;
}