URL: https://m.youtube.com/watch?v=9e4NWnCsrl8&rdm=2num221pl&noapp=1&client=mv-google
Browser / Version: Firefox Mobile Nightly 56.0a1 (2017-07-05)
Operating System: Google Pixel (Android 7.1.2) - 1080 x 1920 pixels (~441 ppi pixel density)
Problem type: Layout is messed up

Prerequisites

1. Account created and signed in.

Steps to Reproduce

1. Navigate to: https://m.youtube.com/watch?v=9e4NWnCsrl8&rdm=2num221pl&noapp=1&client=mv-google.
2. Scroll down the page and tap the “Comments” section.
3. Tap a comment.
4. On the displayed overlay tap “Report spam or abuse”.
5. Tap “Harassment or bullying” option from “Report comment” overlay.
6. Observe “Choose one” drop-down menu.

Expected Behavior:
The drop-down menu is correctly displayed and centered in the overlay.

Actual Behavior:
The drop-down menu is truncated on the right side.

Note:

1. Reproducible on Firefox 54.0 Release (Mobile)
2. Not reproducible on Chrome (Mobile) 59.0.3071.125.
3. Screenshot attached.

Watchers:
@softvision-sergiulogigan
@softvision-oana-arbuzov

sv; country: de

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