针对不同的分辨率优化网站

Iv'e been trying to figure this out for the last few days. Iv'e been leaning HTML and CSS for about a month now so i'm still quite new. In CSS I have position set to absolute with all positions in percentages. Should I write different CSS documents for different resolutions? At the moment I'm basing everything off of 1920 X 1080. From what I understand I need something like a responsive layout but I cant seem to figure out how to get there. I did learn on Codecademy where I made the airbnb page and that seems to adjust itself to different resolutions very well. Iv'e looked over that so I think it might just be something i'm missing. Thanks!Iv'e been trying to figure this out for the las