Thank you Jellby. That looks perfect. ADE didn't like it very much, and iBooks had a slight indent for the title which I might have been able to fix with adjusting the left margin.
A hanging indent did end up working.
Code:
div.sgc-toc-level-2 { text-indent:0; margin-left:5.5em }
.num { width:5.5em; text-align:right; float:left; padding-right:.5em; margin-left:-6em }
https://jsfiddle.net/znwbre26/2/