Web sites vary as to whether they enforce a maximum width for the content within the window. When running Safari full screen on Lion, is there a simple way (without rolling up my sleeves and playing with style sheets) to establish my own maximum width? Lines of text are too long if I happen to be connected to my 24" monitor, but I like how this full screen mode maximizes vertical space.
If you would like to enforce a maximum width across all web sites permanently, you can use a user style sheet file (Safari Preferences → Advanced → Style sheet) with something like the following content:
/* adjust number to taste */
/* horizontal centering */
Nathan's answer is probably more useful, but this is how you could do it if they hadn't included the resizing feature.
(This has a chance of breaking the layout of any web site that's using the same approach to set up a smaller column width than you asked for.)