When I moved my mouse cursor over Impact (Approximate no. of people reached) in my Pro Webmasters Profile Page, few of the contents are not visible. They are going behind the header banner. But I checked some SE sites and they are looking fine. I checked through Firefox 40.0.3. Does it is a bug? Do SE site is not compatible with latest Firefox version?
This other bug report on User Experience site proves it's not specific only to one site: "People reached" tooltip covered by navigation header