As several posters have cited already, 145 is the USDA "safe" temp but there's this problem . . .
Pork accepts heat differently depending on the cut and "Country Style Ribs" aren't ribs, but are slices of roast taken from the shoulder or butt cuts. If you poke around with an instant-read thermometer you'll get different readings on the same piece depending on whether you stick the probe in lean meat, fatty meat, fat, and how close to a bone you might be. Thus, internal temperature for this piece of meat is not the best way to determine doneness.
Suggestion: Learn to determine CSR doneness by feel of the meat. If you push on a lean meat spot with your finger and the meat is spongy, you're underdone. If you get some firmness but can still make a depression, you're close. If the meat is hard and resistant to any pressure from your finger it is overdone. Confirm by using your thermometer in a lean spot if you wish.
I've been using this technique on CSR's and pork chops for years and it works beautifully
Hub