Changed Blockquote coding in blog

I came across this guide for setting up a different blockquote styling in my blog. So, I delved into the HTML and commented out this section

#.post blockquote {
# margin: 1em 20px;
#}
#.post blockquote p {
# margin: .75em 0;
#}

and added this immediately above it

blockquote {
border-left: 30px solid #d9d9d9;
padding-left: 10px;
font-family: georgia, serif;
font-style: italic;
}

with the results you see in this post (and the rest of the blog).
I must admit that I don't understand why the part I commented out referred to both blockquote and blockquote p. However, so far it doesn't seem to have caused any problems.