what versions and OS are you running on ?
Based on the screenshot I reckon you are on some old version with an old browser that does not handle css too nicely ?
I'm not sure this issue is related to OS. It's more likely related to IDE which is Eclipse Luna.
Ok Andreas, sorry you think that way.
If you think it is caused by Eclipse Luna then open bug at bugs.eclipse.org.
If you want me to help you then please let me know what OS you are on since the tooltip in the Eclipse screenshot you are showing are using the native OS browser widget thus the OS is quite important.
You were right, Max. The reason was in IE where font size was set to big. After that I have changed it to medium the problem had gone. Thanks.
Good to hear you solved it.
I actually had expected this was on Linux and that on windows it was honoring the right css. Guess not ;/