How to remove the UI bar (sidebar) margin in Sugarcube?

I managed to remove the sidebar using two methods which were supposed to also eliminate the left margin, but the margin is still there.

Please help! This is driving me crazy.


I'm using Twine 2, Sugarcube.

These are the methods I tried:

CSS:

#ui-bar {
display: none;
}
#story {
margin-left:3.5em;
}

JavaScript:
$('#ui-bar').remove();
$(document.head).find('#style-ui-bar').remove();


ALTERNATIVELY, if this is impossible, can I have all the text in some sort of centered invisible text box? For example like in The Uncle Who Works at Nintendo, so that the text is in the center of the screen but justified to the left.


Thank you very much for your help.