Sidebar not fully responsive

Very pleased with the Foodeez Lite theme. What is the solution for the sidebar not aligning correctly on larger mobile devices (e.g. tablets)? On smartphones, the mobile theme shows nicely with the sidebar moved below page content, but on tablets the sidebar is compressed below and to the right with whitespace filling the rest of the page, and this appears awkward. Thanks in advance for your input!
https://www.lattitudebistro.com