Thanks for changing it back, I realised the <font> tag was just a red herring.
The real issue is that you have a child element that is larger than its parent element…
Parent (width: 100% = 1070px)
<div class="bx-viewport __web-inspector-hide-shortcut__" style="width: 100%;overflow: hidden; position: relative; height: 146px;">
Child (width: 1140px):
<div id="tab-slide1456834665-1-79" class="tab-pane" style="float: left; list-style: none; position: relative; width: 1140px;">