Changing the font in the style sheet doesn't seem to be taking

I am new to WordPress but have spent a fair share of time hand coding HTML and CSS, so I thought this would be pretty straight forward.

For some reason, I can't get this theme Atahualpa to accept the changes I'm making to style.css. At first I didn't have the permissions set, but now they are. I went into the Editor, and changed:

h1 {font-size: 2.15em; font-weight: bold;}
h2 {font-size: 1.85em; font-weight: bold;}
h3 {font-size: 1.6em; font-weight: bold; }

to

h1 {font-size: 2.15em;}
h2 {font-size: 1.85em;}
h3 {font-size: 1.6em;}

and changed:

code, pre {
font-family: "Courier New", Courier, monospace;
font-size: 1em;
}

to:

code, pre {
font-family: Georgia, "Times New Roman", serif;
font-size: 1em;
}

And clicked update file.

When I view the file, there is no change in the fonts. What am I doing wrong? Am I not supposed to get inside the style.css file and change it?

Thanks so much