I've altered the CSS to remove the border-bottom on all .sections, except the h2 ones. I've also altered the border-widths so each .section h2 starts and ends with a thick border and other .sections each start only with a thin border.
Removing border-top from .section h4 to h6 won't make a difference really as AFAICR I only use .section h2 to h4 anyway.

although I can remove it (actually from .section h3 to h6 if you think that will be an improvement.
Now frames and javascript are both out for two reasons:
[list=1]
- DaiML doesn't support thhem and is unlikely to as they aren't supported by anything other than [X]HTML. It makes no sense to cripple the transformability of a language whose strength is... it's transformability; and
- both will screw up my precious anybrowserness (and also my future WCAG compliance).[/list:o]
Yes, both charges could be laid at my use of CSS as well, but that was a design choice -- I decided that the benefit of style information outweighed the transformability issues (ie, no style info in phpwiki, bbcode, and so on).