I wonder if anyone has been able to style a Word document or a html page in the style of Latin Learning texts like Nutting’s Ad Alpes or Ørbergs Familia Romana? By that I mean justified text, with lines numbered every 5 lines. Preferably with the two columns on top and the bottom pane for vocabulary and other explanations.
In Word, I have tried fiddling with the margins, and forcing line breaks, but somehow the text doesn’t line up elegantly. And the line numbering doesn’t seem to want to start where I want it to. In html, it’s a bit of a learning curve to create the different sections. Maybe I was over eager to code it manually? 
Maybe someone else is interested in this as well, and has been at it longer or is more proficient than I?
Thanks.
For this type of things I just use a table in Word. There’s probably a fancier way to do this but it works and is easy enough.
See below the result of creating a three-line table, dividing the first line in two vertical parts and the third one in four parts. First line, left part is for line numbers (text is aligned right, not necessary but I find it more pleasant this way), right part is for the main text (justified). Second line of the table is just for adding a horizontal line, it can be omitted. Third line, parts one and three are for line numbers (text is aligned right). You can also add some space between the columns’ left margin and the text (as I did here) if you want to. Last, you can make the table’s borders invisible.
Once you’ve created a template you’re satisfied with, just copy-paste an empty version of it to start a new page.
Thanks @Shenoute for the Word suggestion. Looks great!
I use LaTeX with the reledmac package (https://ctan.org/pkg/reledmac?lang=en) to create texts with line numbers and one or two series of notes. It’s a steep learning curve at first, but it might be worth it depending on your goals. Here’s a sample of something I did years ago:
Presumably one could also create LLPSI-style margins with images and notes, but I’ve never tried.