theming footnotes

[rmflight]

I tried adding

d-footnote {
  color: #E1E8ED;
}

to my css, but it doesn't change the color of the footnote text (the text of the superscript) in the body of the blog post.

It is also not clear what to add to the CSS to change the actual text color of the footnote in the hover box, or the other colors of the hover box. Currently it looks like it borrows from the color set in the main html, which is now white from my theme, so I get white on very light gray, which is not very visible.

This is actually annoying, as it seems like that color doesn't affect the pop-up boxes for citations, but does affect the color of the text in the pop-up boxes for footnotes.

I'm a total noob about CSS and finding the right selectors (as evidenced by #327).