Getting the alugha video player responsive

.flex-video {
position: relative;
padding-top: 25px;
padding-bottom: 67.5%;
height: 0;
margin-bottom: 16px;
overflow: hidden;
}

To make sure that the video player also works well on wide screen displays (16:9 / 16:10) you add also this values to your CSS file:

.flex-video.widescreen {
padding-bottom: 57.25%;
}

Last but not least we have to make sure, that the size of the video window is always following the browser window:

.flex-video iframe, .flex-video object, .flex-video embed {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
}

To embed the video now you just use this code:

<div class="flex-video widescreen">
<iframe src="https://alugha.com/embed/yt/?v=mbOEknbi4gQ" allowfullscreen="" frameborder="0"></iframe>
</div>

It takes nothing more than this few lines of code and your videos will always follow the window size of your browser.