[QA] Text field is misaligned in amp-form

Environment:
Device - Mac
Browser - Firefox

AMP version : 2308181609000

Test case - [1.3.8 Amp-form]

Playground Link - https://playground.amp.dev/?url=https%3A%2F%2Fpreview.amp.dev%2Fdocumentation%2Fexamples%2Fcomponents%2Famp-form&format=websites&_gl=1*1kgsbzt*_ga*YW1wLW83ZWlnQnRSNnV0d0lWS2dEWG1YSmc.&preview=true

Steps:
1) Launch Playground link in responsive mode.
2) Under "Form Custom Validation: as-you-go", type any alphabet.

Observed : Text filed is misaligned.
With alphabet - https://screenshot.googleplex.com/BXJfVDZYsLkyLxG.png
Without alphabet - https://screenshot.googleplex.com/BetLN64VbKr9ZZr.png

Expected : Text filed should be properly aligned even with error message.
https://screenshot.googleplex.com/B9sQvRhgoZL24rq.png

Start with the linked AMP Playground and reproduce the issue in the “Form Custom Validation: as-you-go” test case using Firefox in responsive mode. Compare the field with and without an alphabet entered, then verify that the text field remains properly aligned when the error message appears, matching the provided screenshots.

Written by the indexing model from the issue text.