Handy Beryl Trick For Web Developers
I found a handy trick for making sure things are lining up. You can zoom in on the screen by holding the super key (windows key) and scrolling in/out with your mouse. It gets a little fuzzy, but you can get a good view of about how many pixels off your layout is, then fix it up.
Likewise, windows has an accesibility tool that zooms nicely. It's a lot crisper, pixelated view, but you have to open a seperate app for it.