New version: Narrow it!
Description: set background to green to protect eyes! Drag it to your bookmark bar and enjoy!
Got a big and wide screen, found hard to read as the line goes very long on the webpage, so I wrote the following bookmarklet, hope it helps you as well:
Drag this bookmarklet to your bookmark bar: Narrow This Webpage, click it when you done open the wide webpage, enjoy!
Source Code: you can modify it to other widths if you don’t like 1080px.