I am redesigning a website for our association with around 40 pages, which may be divided into the 4 main categories, each containing the same number of links.
On the old, outdated site, the links were in the single sidebar, which required the large ammount of scrolling due to the font size. The major audience are people over 50, so the aim is not to make the drastic change to the navigation, so they do not get confused and they view the website mainly on the desktop.
The initial idea was to include the navigation on the right side of the header, where each category is a drop-down menu with the links, however drop-down menus are not considered to be the good UX practice, moreover, the navigation appears to be chaotic on the screens with lower width due the long name of our association (25 characters), i.e. there is a small space between the name of the assoc. and the navigation.
The another idea is to use a mega menu, where all of the four categories with their links are listed. Moreover, each category would be visually separated by using the one of the four dominant colors of the assoc. Also, all links on the one screen would resemble the old site's navigation the visitors are used to.
All sources I have found, state, that mega menus are the good decision for huge websites, e.g. for corporations or eshops with hundreds of pages, where each main category has its own mega menu.
Is using the single mega menu for the whole website (triggered by clicking the menu button) the good idea?
Thank you for your suggestions.