Mobile first . HTML / CSS only

Third proyect in 3 days! Lets continue coding.

This one seemed easy at first, but I spent some time with tiny details. My aproach:

1. first mobile version, using advantage of divs as block tag.
2. Use flexbox to move cards around and set sizes in desktop version.

I always have the feeling that my CSS code is very messy, if someone can help me advaice would be great!

Problems that take me sometime to solve:

1. Background for logos(document, folder..). I put those img tags into a div a give that div the color needed. Happy to know if there is an easier way.

2. I spent some time doing the speech bubble in the desktop version. I used pseudoelement ::after to create a div a move it around.

3. Change range input style by default: I didn't imagine that was so complicated haha. I did with a linear gradient. Need JS to change when user move the input. I'll look into it in the future.

All feedback is welcome!! Thanks!