video background VC - img placeholder

Hello!
I'm preparing a page for a client , I use visual composer to put a video in the home , however when I test in mobile devices ( 767px ) the video disappears and I can not put a background image for these devices (img place holder). Any idea how to fix this?. Additional to this the video shown is very large and looks bad. I've try tu set up on Visual composer parameters but it doesn't work. The test site is http://www.taufapublicidad.com/rosita

Hello,

Unfortunately the Quark theme is not compatible with Visual Composer. It's probably a conflict with theme and plugin css/js code.

Was this solved? I see a video in your page, can you share the solution? thanks!