CSS Bug in Chrome, Safari, Vivaldi

The bug has been found in these browsers:

• Chrome, v. 54.0.2840.98, macOS
• Chrome, v. 54.0.2840.99, Windows
• Safari, v. 10.0.1, macOS
• Safari Technology Preview, rel. 17, 10.1, macOS
• Vivaldi, v. 1.4.589.38, macOS

The bug does not appear in these browsers:

• Firefox, v. 49.0.2, macOS
• Internet Explorer, v. 11.0.9600.18524, Windows

Description of the bug:

The table cells containing 4 and 5 get rendered with a heavy (3px red) border-bottom, but the CSS specifies just plain "1px solid #bbb".

If the "bot" class is removed from the cell containing 3, then the problem goes away.

The border-top of the cells containing 4 and 5 seems not to be affected by the bug.

This bug has been reported to WebKit Bugzilla.

First version: 15-Nov-2016 Updated: 12-Dec-2018