Re: increase/ decrease font size as in doc.tikiwiki
The doc site uses the Site Identity feature for the top of the page, and the new theme (Mittwoch, an adaptation of a Joomla theme) also has a navbar.tpl file that holds the horizontal menu and font/color changing links.
There are onclick javascript links for the size changes in this navbar.tpl, but they could be in a theme's tiki-top_bar.tpl, tiki.tpl, etc. The theme's header.tpl has a link to the javsscript file used (needed to load in the html head section). You can see all this if you look at the source of the completed page, and find the URl for the javascript there as well (md_style.js).
For the text to resize, the theme must specify font size using % and/or em. Text given a px size won't resize.
I'll document this in more detail when the theme is available to download here, which won't be long.
-- Gary