div = document.getElementById("centralNotice"); div.parentNode.removeChild(div); div = document.getElementById("mw-page-base"); div.style.marginTop = 0;
Seems like I also have to set #mw-head's top to 0 and #mw-panel's top to 160, otherwise they're still shifted down. Seems like the page fixes them with JS, maybe, since they reposition if I resize the browser window.
Fix top margin
div = document.getElementById("centralNotice");
div.parentNode.removeChild(div);
div = document.getElementById("mw-page-base");
div.style.marginTop = 0;