Having an issue with body width that seems strange. Check out this fiddle link to see for yourself.
<div class="topbar" style="width:100%; background:#000; color:#fff">
<div class="container" style="width:970px; margin:0 auto;">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus posuere semper velit, quis gravida dui elementum posuere. Aliquam hendrerit sagittis sapien elementum lacinia. Praesent sagittis, magna sed molestie suscipit, dolor ante pharetra neque, a ornare lorem arcu eget mauris. Donec ornare cursus velit vel mattis. Donec malesuada eu...</div>
</div>
The issue arises when the content width exceeds the window width, causing the body to take on the window's width rather than the content's width.
Observe the screenshot below. The window width is 787px while the content width is 970px. A horizontal scrollbar appears as expected.
However, notice what happens upon scrolling right. Instead of expanding to occupy 100% of available width, the body sticks to the window's width.
Any insights into why this behavior occurs?