Change website video background to use Youtube - plus more work coming up

The Concept Place is a new type of company, based in Britain. We take care of everything for startups - web design, data analysis, logo design, graphic design, animations, digital marketing, branding and more. We are always looking for new partners on Freelancer to send work to. Please bid competitively as we like to work with the same people for many projects and will forward more work. We are looking for good web developers to work with. We have a quick project for you. Our website is using video backgrounds with the video served from the server. We would like to switch to video background using youtube. We would also like this to work on mobile devices if possible, I have heard that there is ways to achieve this (showing the Youtube video even on mobile devices) --- if not then we would like image backgrounds for mobile devices and youtube background for desktops. Website: [login to view URL] Website is in PHP, HTML and CSS (not a CMS).