Blogr landing page solution with HTML, CSS, JS

Big s/o to @Yazdun, who gave me some tips about CSS animations. By the way, I guess I should go through SCSS, since my stylesheets begin to be veeery long ! I'm particulary happy about my .wrapper system, which avoid me to use Bootstrap. I think I'll reuse this .wrapper in the future. Feel free to take it, if you judge it relevant ! Also, this little tool helped me to crop .svg image.

Place to the questions, now :

• Can I inherit from upper @media query ? Or is it more secure to inherit from the original one ?
• If I can't, what would be the best practice to position backgrounds without to use media queries, taking resizing in consideration ? Background-position ?I'm mostyl talking about white sections.

Hope you'll like it ! I had some fun playing with those kind of "breathing" effect ! I didn't spent much time in the .js, but it seems functional.