Space tourism multi-page

Hi, yes it's not responsive, i just took the frame sizes from figma and just position: abosolute my way through, i just made a mess of things and try to fix them. Also having problems with the navigation where the page is refreshed or went back but the borderline indicating what page you are doesn't move, still can't find the issue and the mobile just keep the side bar menu open whenever i refreshed without the function being triggered.

Thanks for the help