Let's say I have two pages with the same code block containing two lines, and I'd like to emphasize line 1 on page 1 and line 2 on page 2. If I do that currently, the code shifts by about a line between slides, so that the emphasized line is in the middle.

Is there any way to avoid that layout shift?

What I'm currently doing is adding empty lines to the code block, which are always emphasized, e.g.:

three backticks jsx 1,2,4

1 # this is line 2, and is the only line I'm "actually" emphasizing
2

three backticks

But this requires me to disable formatting on save :/

Is there a more idiomatic way to do this?