WordPress CSS not working properly

This isn’t about the database at all. First of all be sure that it isn’t any cache problem or something like that. Try with incognito mode or another browser and check if the issue persists.

If you still don’t see any CSS applied, well most probably there isn’t any CSS file loaded in the page.

Check the source code of the page and check if you can find the CSS file loaded, if yes check it’s content. If there isn’t then try to find in your theme files where the CSS file is supposed to be loaded. Searching for wp_enqueue_style in the whole folder should be enough (maybe also search for wp_dequeue_style to have some other clue).

If you cannot find any useful information, try to deactive all the plugins and check if the behavior persists.