Embedded videos won't maintain their aspect ratio as the width of the screen changes. To avoid squished videos, wrap them in a container with the class .flex-video.
The default ratio is 4:3. Add the .widescreen class to change it to 16:9.
Embedded Vimeo videos are special snowflakes of their own. Add the .vimeo class to a flex video container that wraps a Vimeo embed.