It's going to be really complicated to do what you want with the way you'd like because of how HTML is processed.

You cannot have a leaf of your markup continued on another branch. What I mean by that is that any opened tag in an element is required to be closed in this element like so:

<li>
  <mark> my text to be highlighted </mark>
</li>

It is still not impossible to do but you will need to use at least some CSS and HTML tags and depending on your use-case, some JavaScript.

Here is the answer to another question which should help you solve your question: https://stackoverflow.com/a/75464658/13025136