Here are two examples of how to add responsive video to a post or page.
Add a responsive Youtube video by using the video include.
Input:
{% include video.html src="https://www.youtube-nocookie.com/embed/RjggipNdmXw" %}
Output:
<div class="aspect-ratio aspect-ratio--16x9 w-100 mb4">
<iframe class="aspect-ratio--object" src="https://www.youtube-nocookie.com/embed/RjggipNdmXw" frameborder="0" allowfullscreen></iframe>
</div>
Add a responsive Vimeo video by using the video include.
Input:
{% include video src="https://player.vimeo.com/video/198045963" %}
Output:
<div class="aspect-ratio aspect-ratio--16x9 w-100 mb4">
<iframe class="aspect-ratio--object" src="https://player.vimeo.com/video/198045963" frameborder="0" allowfullscreen></iframe>
</div>