fix line number placement

Global font size in each style sheet has been tweaked very carefully so
that the precise line height is very close to a whole number of pixels,
so that precision alignment using em, which aligns something
precise (top: 13.5em) to something inprecise (line heights, with
accumulated errors due to rounding in every line), is not lost.

Note that Firefox is NOT supported, since each line seems to always
occupy one more pixel than the calculated line height.

For some reason line numbers in the print view are still rather
problematic at a page continuation. In Chrome and Safari, the first two
line numbers on a new page tend to overlap, so everything afterwards are
off (and on Firefox line numbers do not show up on the second page at
all). Anyway, printing shouldn't be a big concern.

0 files changed, 0 insertions, 0 deletions