Or just spend an hour or so figuring out how basic styling form styling works. If you pull in a framework for every itch you have to scratch (even as "lightweight" and standardized as Bootstrap), without taking the considerably greater time to actually understand the framework actually works -- you'll likely regret it some day.
Usability-wise, the biggest issues I see are:
- even after we select for English, we still get captions in German.
- in the hover help boxes (that appear over the green "Leistung" bars), all the performance metric (?)names are camelcased; presumably because they are fresh out of some database. These should also be proper names, the way they normally appear out in the wild.
- there's lots of wasted space. The entire result set should fit on one page, with no need for scrolling, if at all possible.