Do you still haven’t found a webmaster familiar with browser annoyances on Mac?
Hi, my name is Matt Sergei (do call me Matt) and can help you (25 year a webmaster and IT developer).
Please provide more details where you have issues with your visualization on Mac (and correct screenshot for Windows display or so, I guess you have this or something similar). Usually Safari is the biggest obstacle requiring to have several long written CSS rules (no shorthanded ones) to display web page objects as desired.
Looking forward to your reply,
Matt