Website layout looks very different in every monitor

  1. The working site looks correct at 1080p view but not when it goes to 2560 or bigger monitors
    https://www.premiumdigitalcontrol.com/
  2. But when viewing in admin, the layout is all over the place.
    Webflow - PDCA Website 2022
  3. It’s also different on a mobile phone view from an actual phone against the view on Inspect element on Google Chrome.

I have been thinking of replacing the site’s use of PX to REM to fix all these inconsistencies. Sometimes the layout in Preview is Ok but not on Mobile view and sometimes it’s the other way around. What’s happening to the site?