change font dyanmic

Hello all. I have a page that prints an address label. Sometimes the address is long and wraps to a second page. Is it possible for CSS to shrink the font size if the label will print on 2 pages. I can just lower the font size in my CSS but most all the labels print fine in the larger font.Thanks for all your help.
Tracy

Apply a separate style to those addresses that are very long? You know how CSS works and is used, right?

And maybe it would help to see some code.....

How can I apply a seperate font size say if the charactors reach 30??