Unknown origin of code in rendered HTML

Question

This is homework. I'm creating an ASP.NET site using Master Pages, in Visual Studio 2012, and my navigation menu is too far to the left. This is part of the rendered HTML, but I don't know where it's coming from, because I did a search in the whole solution for keywords contained in it. I closed my browser, reopened it, cleared my cache, but the nav menu is still too far to the left. I was using some css I copied from somewhere, but I deleted most of it.

<a href="#NavigationMenu_SkipLink" style="position:absolute;left:-10000px;top:auto;width:1px;height:1px;overflow:hidden;">Skip Navigation Links</a><div class="menu" id="NavigationMenu">

Answer 1

Maybe it's these settings: position:absolute; left:-10000px;