Why addressing html *and* body?

Why [do you address](https://github.com/kennethormandy/normalize-opentype.css/blob/master/normalize-opentype.css#L6) both the `html` and the `body` element for the root styles? Shouldn’t it be sufficient specifying just one of them?

Start with normalize-opentype.css at line 6 and review the declarations applied to both html and body. Check the relevant CSS root-style behavior to determine whether both selectors have distinct purposes; done means recording the rationale or a clearly scoped documentation change on the issue.

Written by the indexing model from the issue text.