This is wrong set of questions to ask for a Frontend Developer position. This is perfectly fine for those who are building tools for Frontend. I knew most of these questions primarily because that is what I love doing. I, however, won't expect any frontend developer to focus on this as this is not the job of a frontend developer (more a job of tooling developer if that is even a thing).

The reason you have CSS style tags at the top is because it is an optimization technique for having critical CSS added to the <head> tag to ensure that styles of top of the page are rendered immediately (so no flash of content). I can bet anything that "-ms-text-size-adjust" is not something any Twitter Frontend Developer would be aware of unless they are building the tooling for the Frontend. This actually comes from normalize.css which every Frontend developer just blindly imports: https://necolas.github.io/normalize.css/8.0.1/normalize.css

This normalize.css is critical style as it resets the browser styles. Hence it is added above the fold (in the <head> tag) to ensure that the initial page load won't have any flash of content.

Honestly, this is a very bad way of judging Frontend Developers. My biggest critique of hiring process for Frontend Developers is precisely this. Either interviewers ask questions related to solving data structures and algorithms (which honestly you never use in majority Frontend Development anyways) or such esoteric questions that won't be useful anywhere else except for clearing the interview process.

Want to hire a Frontend Developer? Just ask them to code a sample project: possibly a Todo list. And focus more on how they organize code, how they structure components, what libraries they choose, how they test the components, are they aware of the latest standards (are they still using React createClass or using functional components with hooks)?. This is the only correct way to judge a candidate for the position of Frontend Development. For Senior Frontend Development roles, you can ask them about how they would work with tooling that connects with the backend. Probably give them a GraphQL endpoint and see how they approach it. Do they use a mock adaptor? How do they integrate Authentication? How do they put guards around pages and how do they handle role management within the app? How do they handle internationalization? Would they resort to by default picking Redux (just because it is popular) or is there a better alternative for the specific project/task at hand? These are much much better questions that gauge the experience of the Developer.

All these other methods of interviewing are basically admitting that you have no idea of how to filter correct candidates or you want to show off your esoteric skills. This also sends a very wrong message to the Frontend Developer community that the requirement to get a job is to learn all these hidden features and edge cases. It will sidetrack them from becoming the best at their job as they spend countless hours read/learning things that in no way contribute to business outcome.

Honestly, seeing all this, I have a strong urge to do something about the hiring process. Maybe a startup along these lines. The hiring scene in Frontend Development sucks.