Custom Video Styling

Custom 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%;
}

.entry-content img,
.entry-content iframe,
.entry-content object,
.entry-content embed {
        max-width: 100%;
}

Custom DIV

<div class="video-container">
<iframe width="1280" height="720" src="paste your yourtube link here" frameborder="0" allowfullscreen></iframe>
</div>

Cheers!