At least in Firefox, when you have >1 line of text in Assistant's input area, the last line is progressively obscured by a fade effect, which decreases readability.
It scales with viewport zoom level. Close-up at 500% zoom:
Both screenshots taken in a brand new Firefox profile, no add-ons, 140.12.0esr. I see the same behavior in Firefox Android 152.0.6.
I'd expect to not see fading of text that the user is editing.
