This has me scratching my head. Why are you using <div> for everything? HTML5 has been a thing for years, along with semantic tags like <header>, <footer>, <nav>, <main>, <aside>, <article>, <section>, etc. Or is this intended for people still using HTML4 or XHTML? Also, why do you need a <div> for image captions? That's what <figure> and <figcaption> are for.
Also, anybody who cares about web accessibility is going to run into needless misery using this stylesheet.
https://wave.webaim.org/report#/https://isneuu.com/css-blog-...