Oh, the joy of web design. Chrome was behaving as it should, but Internet Explorer 11 wasn’t. I had a header div element on my body, but the background from the main page was showing above the header. I was using a negative margin along the top, like so:
What worked for me was modify the units for the margin-top statement to “vh” instead of “px”:
This did throw off the Chrome alignment slightly, and it wasn’t exactly vertically centered as it was before, but it was pretty close, and I was happy enough with the result to not throw things at the screen.