<div class="video-container">
    <iframe width="560" height="315" src="https://www.youtube.com/embed/qtDR454vFeo" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
</div>
<style type="text/css">
.video-container {
    position: relative;
    padding-bottom: 56.25%;
    padding-top: 30px;
    height: 0;
    overflow: hidden;
}

.video-container iframe,  
.video-container object,  
.video-container embed {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}
</style>