pushing logo to the left, beyond the page limits

i’m using the twentytwelve theme and i have a logo that has a strong vertical element that i would like to align with the edge of all the text.

hard to explain, but it appears that the text and horizontal lines and whatnot all start 40px from the edge of the … “site-box” for lack of a better term.

if i use this post as an example, i want my site logo (.site-logo) to be aligned with the words “Forum”, the Title of my post, the edge of my avatar, etc. and NOT have to align with, say, my username.

i’ve been playing with this, but it appears there’s a higher order inheritance going on:

.site-header hgroup {
	display: none;
}

.site-logo {
	max-width: 100%;
	height: auto;
	padding-left: 0px;
	margin-left: 0px;
}

this is perhaps the worst description i’ve ever written, so sorry about that. i imagine this applies: https://www.youtube.com/watch?v=5hfYJsQAhl0