So I'm still new to the whole css and div thing, pardon my bad coding. :/ Anyways, I have finished a site but oddly the side navbar does not appear on mobile browsers such as Chrome and the default android one. Any ideas as to why? All help is appreciated.

<http://escobarboxing.com/>

Also, I've tested it on my Desktop via Chrome, FF, and Opera and it appears to be working fine but another user using Chrome said he did not see it?