Page text disappears outside of edit mode

Hi there, I am having issues making my first website. I used custom code to make my logo white on a page with black ground but now my paragraph text has disappeared. I have played around with the style menu and everything looks great in edit mode but when I click save the page goes blank. Please help, friends!

Edit mode:

Live site 😞 :

This is the code I used:

<style> 
div.header-title-logo a {
content:url("https://static1.squarespace.com/static/6476b9f30c2e09459f205a09/t/64af4eb0812414558109d02c/1689210544662/Test+Logo+Wht.png") !important;     
max-height: 30px;
}
</style>

Something is happening to your portfolio page titles, they don't appear in the code, as if you haven't set them. Can you try removing any CSS temporarily whilst looking at this page to see if that helps? (copy and remove the CSS then paste it back in, please don't lose your CSS when doing this!)

Also I see that the white logo is on the work pages that have a white background so it is invisible. Is there custom code to make it so that the logo is only white on the work folder not the individual projects?

"Something is happening to your portfolio page titles, they don't appear in the code, as if you haven't set them. "

...and "setting them" would entail what exactly? Sorry this question is probably quite slow but I just started using this template and I don't think I haven't "set anything"

So I think this is the issue.

Thanks again, I will do some research on my end. 

Yes I have done that (ie the bare min). I think I am going to scrap this page because is it wonky. I think it is the logo color code so I will keep my site with one ground color, it is not the end of the world. Thanks for your help!