Technical Documentation Project - fullbody workout

Hello,

This is my third attempt at this project.
Overall, it did turn out much better than the first two, but there are several things that displease me.

#1: On a mobile view, I couldn’t get the <a> to become inline elements and wrap. They kept being treated as block elements.

#2: Design. Though it improved a lot in relation to my first attempts, I think the design looks cheap and ugly. I suppose the biggest issue is my lack of planning ahead. Do you design first on paper to set a layout goal? I felt most of the elements were improvised on the go.

#3 Messy code: I feel like my HTML and CSS are very messy and it is becoming harder to find a specific tag or style that needs fixing. How do you organize your css? Do you recommend following something along these guidelines? https://learn.shayhowe.com/advanced-html-css/performance-organization/

Thanks for any feedback in advance: