Hello Siam,
A rough starting point is this:
jmp.sh/kr877f4 you will however to move these styles into a media query block with a min-width.
Another (better) approach would be to use a grid system like Bootstrap which is already being used in your template. You should ask the template's developer on how to do this
As for overriding the default og:tags, you can use Joomla!'s API in order to use custom meta tags
docs.joomla.org/API17:JDocumentHTML::addCustomTag