Since we no longer change the selected message's background color, it
doesn't make sense for these other colors to still change when the
message is selected.
(imported from commit a7c387e7d390b7f2973dc6bd3168651d88880139)
The width setting was unintentional, and it interferes with
the inline-block settings for the image and bot info.
(imported from commit 741c82829efed00b6d47badcf14b26223b47a7a9)