anastrophic 😡frustrated

Maybe you guys can help me. *begs*

Is anybody CSS knowledgable? I used to be, but I haven't used it in so long that I've basically forgotten everything.

I want to make my text size smaller without having to put it in every entry. Therefore, I need an override. I know I need the GLOBAL_HEAD and the thingy. But I basically have no idea what I'm doing. I don't know what order anything goes in or what to put, basically. Halp guys! I'm frustrated as crap. everything_lj gave me this, but i've tried that and I've got nothing.

body
{
margin: 0;
color: #333333;
background: #6699CC;
font-family: 'Trebuchet MS', Verdana, sans-serif;
font-weight: normal;
font-size: small;

line-height: 150%;
}

=(