Can the indentation of items in the sidebar be controlled for all font sizes?
Indentations appear normally for small fonts, but become irregular for larger fonts.
Technical note: I am viewing define.xml files in Internet Explorer.
Do you mean the result of the stylesheet as seen in the browser?
If so, this has nothing to do with OpenCDISC.
CDISC (which is something completely different than OpenCDISC) delivers a sample stylesheet for define.xml, but it is your own responsibility to use it (or another one) or to modify it to your own requirements.
By the way, what you see in the browser is not the define.xml, it is a TRANSFORMATION of your define.xml by the stylesheet into HTML.