Oshine HTML - formatting Chrome vs IE

I’m having an issue with the Oshine HTML template, specifically the right-sidebar-page compatibility between Chrome and IE(11).

I’ve modified the HTML of the right-sidebar-page. I removed the sidebar and replaced it with accordion toggles. The page renders correctly in Chrome, but in IE the one-column, be-custom-column-inner (the main page content) text is truncated on the right side, the header image is larger in IE than Chrome (and cropped on the right by about 1/3), and the accordion toggles don’t show (but the toggles header “Recent Posts” does show). I haven’t messed with any of the page formatting as far as I know, unless I accidentally removed some when I replaced the sidebar. The page is not online, so I can’t provide a link, but I will try to attach a couple screenshots. Thanks for any assistance.

No one?