Visit https://www.wikipedia.org/
After you click on the 'Read Wikipedia on your languages' button and open the list, the line near the button expands. When hiding the list, the line remains in the same position, although it should be narrowed.
Win10, Google Chrome.
Current
Expected
Cause
Interesting browser bug:
When the list is closed .lang-list-active .lang-list-border { max-width: 85%; } rule is unapplied, but the original .lang-list-border { max-width: 460px; } rule does not take effect / restrict the width.
Solution (workaround)
Replace max-width: 85%; with max-width: unset;