In a couple of projects I'm currently working on, the CSS for them was causing me problems between the 2 browsers. Willing to admit that I don't have an intimate familiarity with CSS best practices. I look up what I think I'm trying to do, and then implement what I've found. I primarily use Firefox while I'm coding, and then only check with Chrome and Safari periodically. I've had to circle back to fix CSS issues specifically for WebKit not rendering as expected. Eventually, I can get to something that works across all the browsers I have access (no Android devices anywhere).