This'll align all the Idea Group infoboxes accordingly; if not all of them should have their align changed but only specific ones, though, then let me know!
Also, please keep in mind that multiple infoboxes on an article behave rather unlike you'd expect on mobile. Have a look at how it looks on mobile skin. As you may notice, the Early Administrative Ideas infobox appears outside Administrative Groups section and at the very beginning at the article, which I assume clashes with what you'd want readers to read. That's how the first portable infobox on a page is supposed to work. The "trick" I'd use to get around this behavior is to add <infobox></infobox> right at the start of article, like so:
<infobox></infobox> As a nation develops technologically, [...]
The Early Administrative Ideas infobox would no longer get interpreted as the first infobox, then, and hence the order of infoboxes will remain as intended.
Edit: Added CSS for left-aligned infoboxes, too, in case you'd prefer them over center-aligned ones.