Middle-clicking in the top bar doesn't open a new tab.

It doesn't, just checked in Chrome.

There are three ways the website can display:

1. Full Desktop - The menu options "Home", "News", "Game", etc are displayed horizontally
2. Compact Desktop - The menu options are hidden in the hamburger menu, but you still have notifications
3. Mobile - Hamburger menu and no notifications. (You're better off setting the site to Desktop Mode than using this mode until that's fixed...)

In Full Desktop mode using the middle mouse button triggers an animation and redirects the current page. In Compact Desktop mode the middle mouse button opens a new tab.