Hi Jess,
It’s under Appearances> Editor. On the right, you’ll see stylesheet.css.
Also, under Appearances is an “Edit CSS” option (I think you have to have the Jetpack plugin installed for that to work…
In order to center it on just one page/entry, I used this code in the text area of my single page:
<style type="text/css" media="screen"><!--.soliloquy-container {
margin: 0 auto !important;
}
--></style
