One of the issues you may have if you try and embed YouTube or other media into your web site is the view on a mobile phone does not work. Normally the embed code you are supplied has fixed dimensions for displaying on wider format screens.
embedresponsively.com helps build responsive embed codes for embedding rich third-party media into responsive web pages.
The code here is based on research and work by Theirry Koblentz, Anders Andersen and Niklaus Gerber.
The site is created and maintained by @jeffehobbs.
This is a really useful resource which saves time when creating content for blogs and web sites.
Embedding Responsive Content