This commit restores a small check for a match of the query,
so that when you load in dark mode, the clock loads in dark(ly).
Without this commit, it would only shift modes as part of a media query
change.
Trying to use a transparent background revealed constant
redraws each second -- this commit returns a color
declaration to the background, changing with the media query.
Previously, we used addEventListener, which was returned by the
media query as an inheritance from the window object.
Safari doesn't support this, but it, and all browsers,
support an alias that uses function-based checks.
This commit uses that alias.
