How do you optimize the layout of a responsive site?

Question

css

Hello. I wanted to ask how you delete, add scripts, pictures, etc. for different screen extensions? (for example, disable the wow.js plugin for screens below 480px, for the same extension, remove the image and add the same one, but with different sizes (that is, smaller (well, or larger, depending on the situation)))/
In general, we are talking about optimizing files so that different extensions do not load the user with extra kb-mi (mb-mi?)) of traffic.

Answer 1

I do resizes for desktop and mobile in advance, with the help of detection I determine that the user has logged in through the mobile and stick pictures of a certain size to him.
Now it’s a sin to complain about hosting space, there are no problems and you can store several versions of the resize.
For scripts and styles, also use detect.
For example, in PHP, as an option, you can use such mobiledetect.net