How to add hover text?

Awesome, thank you!

Hi team - this works nicely. however, I was wondering if someone might be able to assist with editing this code (it is possible to nest?) so that I am showing a wealth of information? I have the HTML code that I want to use for the data to be shown in its format (overarching theme/definition underlined and bolded, with a few bullets underneath, but I am struggling to get this to nest within the span so that this is the information shown within a rollover. below is the HTML code that I would like to include in the rollover:

<p><span style="text-decoration: underline;"><strong>GENERAL KNOWLEDGE REGARDING FERTILITY AND INFERTILITY</strong></span></p>
<ul>
<li>The postponement of parenthood may increase the number of couples experiencing infertility and prolong time to pregnancy.</li>
<li>Research has revealed that childless people are not well informed regarding fertility, which may threat[en] their childbearing intentions. (Santos et al 2017)</li>
</ul>