Multimarkdown footnotes are pretty useful. If they are enabled in a
wiki, they don't look so good with the default stylesheet, however, as
the references are in the same size and positioning as everything
else.

The following stylesheet should be added to `style.css`:

    a.footnote { vertical-align: super; font-size: xx-small; }
    div.footnote { font-size: smaller; }

This is a typical style that user-agents apply to the `<sup>` tag. For
example, chromium has this builtin style for `<sup>`:

    vertical-align: super;
    font-size: smaller;

Bootstrap uses this instead:

    sup {
        top: -.5em;
    }
    
    sub, sup {
        position: relative;
        font-size: 75%;
        line-height: 0;
        vertical-align: baseline;
    }

I settled on `xx-small` because it's the only size that doesn't affect
line-height here. However, Bootstrap's way may be better.

At any rate, the correct way to fix this is to *avoid* custom styling
and use the `<sup>` tag for the footnote reference, as it has
*meaning* which is important to have proper semantic output (e.g. for
screen readers), as detailed in [this Stack Overflow discussion][].

[this Stack Overflow discussion]: http://stackoverflow.com/questions/501671/superscript-in-css-only

Note that I also make the bottom `<div>` small as well so that it has
less weight than the rest of the text. -- [[anarcat]]