Describe the bug:
My personal microblog uses order to change the placement of the "posts by month" sidebar between mobile layout to normal layout. When switching from mobile to normal layout, the page animates over 0.8s, and when the animation ends, the sidebar gets "stuck" with the wrong order until you move the mouse onto it.
Correct order:

Order after resizing (this changes when you mouse over the element):

To Reproduce:

• Go to my microblog page https://fairysvoice.net/microblog/. Notably this page has * { transition: all 0.8s; }
• Resize window to less than 1200px width. This causes article to gain order: -2.
• Resize window to bigger than 1200px. article loses order: -2.

In Firefox, doing this causes the order to correctly change halfway through the animation.

Platform:
Windows 10, using latest nightly Servo