I am in the process of redesigning a website to optimize it for mobile devices. Although I have completely restructured the site, I am encountering an issue where the main pages are not displaying properly. The header, navigation menu, sidebars, and a placeholder image are showing up in the main section, but the content of the main pages is not loading. I am trying to avoid using iframes in my solution. Specifically, I am having trouble with the navigation links not pointing to the newly created local or internal pages. Despite researching extensively, I have been unable to find a solution that works for me. It is likely a simple problem, but I cannot seem to identify the root cause. Any assistance would be greatly appreciated... Thank you in advance.
The code snippet below includes JavaScript functions for opening and closing the sidebar, as well as CSS styles for various elements of the site layout. Additionally, the HTML markup defines the structure of the site, including the header, navigation menu, main content area, and footer.