Social Media Dashboard with pure HTML, CSS and 2% JS

The positioning took some real getting used to in CSS. I'm a fast learner so as I figured out that using container div for multiple divs helps with positioning and sizing, I was on a roll finishing the challenge.

I will say, I'm still very skeptical about my skills with position properties in CSS. But I'm sure the more I learn, the better. Does anyone know any article, video tutorial or any material on positioning? I may have found a fix for it in this project but I'm sure it'll be a challenge in future.

Is it ok that everything I did was just raw CSS, HTML and JS, no tools or libraries used.