Rounded Corners on All Your Post Images

Hi guys!!!! It's been so long since the last tutorial was posted on here!!! So here's a quicky welcome back tutorial :~)
How to Make all your Post Images Have Rounded Corners wow this is a long title
Here's an example of what I mean:

1) Sign into Blogger, then go to Template > Edit HTML

 2) Hit CTRL+F (Command+F on Macs) and search for the following:

.post-body img

OR

.post img

3) Under .post-body img/.post img add this code:

border-radius:15px;

You can change the 15 to any number you'd like. Decrease it to make the corners sharper, or increase it to make the corners rounder.
Your end result should look something like this:

4) Save and you're done!

Good luck and have fun! ^_^ Until next time,