I use external style sheets on all of my stuff.
There are some browser/platform only tags that I stay away from.
My link list does use the scroll bar color tag that is IE only but I don't use it on my other stuff and it will be most likely killed next time I do a redesign. Actually my LL was the first place that I ever used styles extensively and there is much that I would do there differently knowing what I know now.
In any case I'm always sure to make sure that my pages look good in a few browsers.
BTW
Safari shares its code with the Linux browser
Konqueror so it handles web pages pretty much the same.