Absolute positiong is what you want to use for the results you want.
From W3Schools:
An absolute position element is positioned relative to the first parent element that has a position other than static. If no such element is found, the containing block is <html>:
That got me working backward through the parent elements until I found the culprit. Your #content-wrap is set to position: relative, so the banner was positioning itself relative to that container which tops out just below the header.
Setting it's parent element (#container) to position: relative; and forcing the #content-wrap to position: static; seems to work for your theme without breaking any other layout that I can see.
Give this CSS a shot as a starting point and see how it goes.
#container {
position: relative;
}
#content-wrap {
/* !important is required for this to work, but I couldn't track down why */
position: static !important;
}
.corner-info {
position: absolute;
top: 0;
right: 0; /* switch this to left: 0 to position in top left corner */
z-index: 200;
width: 180px;
height: 180px;
}
Before I found the solution above, I wanted to check to see if any CSS typos were causing the problem. I ran your CSS through a validator (http://jigsaw.w3.org/css-validator/validator). It came back with these errors you should clean up. The numbers indicate line numbers in your custom CSS.
To get a bold font, use font-weight: bold;
51 h1, h2, h3, h4, h5, h6 Value Error : text-decoration bold is not a color value : bold
Not sure what this error means (of if it's really an error)
419 Sorry, the at-rule @-moz-document is not implemented.
You've got a "\u201c" double quote instead of a normal double quote (likely from a copy/paste from a word processor)
447 blockquote Value Error : font-family Lexical error at line 447, column 31. Encountered: "\u201c" (8220), after : "" “Times New Roman”, Times, serif;
454 Value Error : font-family Parse Error [: italic; padding: 3px 10px; } /*- COMMENTS ----------*/ .comments-box]
These are missing a value text-align:; should be text-align: left; (or center, right, etc.)
572 .signup Value Error : text-align Parse Error :
581 .infobox Value Error : text-align Parse Error :
619 .sidebox Value Error : text-align Parse Error :
These should be left: 0; (negative values not valid)
597 .infobox h3 Value Error : left only 0 can be a length. You must put a unit after your number : -15
635 .sidebox h3 Value Error : left only 0 can be a length. You must put a unit after your number : -15
These should be color: blue;
662 table.guest-commenting Property text-color doesn't exist : blue
667 table.guest-commenting td Property text-color doesn't exist : blue
672 table.guest-commenting td input Property text-color doesn't exist : blue