Static fluid boxes

I actually went a different route with what I was trying to accomplish, so I do not have any pictures.

I was trying to get one bullet point to appear at a time when the user clicked a click box. At first I had all of the bullet points in one text box, and I could not find a way to make them appear one by one. So I added white smart shapes boxes that I placed over the bullet points. I would make each of the white boxes disappear with each click of a click box. The problem with this was that when the text would increase its size in the preview mode, the white text boxes no longer aligned with the text. I had trouble adjusting because in edit mode the boxes appeared aligned with the text perfectly.

Instead of using this method, I figured out that if I made each bullet point in a separate text box, I could easily make them appear one by one using the timeline. The text didn't change its size because I didn't use static fluid boxes (although it wouldn't have mattered if the text did adjust its size, because I no longer needed the white smart shape boxes to cover up the bullet points in this method).

I would still like to know how to keep the text from changing its size though, because this has been a problem in the past as well and I would like a solution. The size of the text box is not the problem. It is the text inside the textbox that changes its size, no matter if the text box is too big or too small.

Thank you!