Adjust left menu to work at 200% magnification

[atsansone]

Hotlist: https://buganizer.corp.google.com/hotlists/5891206
Bug: https://buganizer.corp.google.com/issues/337893089

Observed Results

When the zoom reached 200% can be noticed that the left menu cannot be closed once the user has opened it.

Voiceover

Expected Results

The left menu should be able to be closed at high levels of zoom

User Impact

The users that have sight issues and need a high level or zoom, can have a challenging situation since the whole page content cannot be seen correctly.

Steps To Reproduce

1. Go to https://dart.dev/overview
2. Go to settings in google chrome and select the + in order to increase the zoom
3. Notice that the menu in the left cannot be closed when the page is at 200% zoom

Relevant GAR Sheet

A11Y Tracker

GAR Details

GAR 1.16 (a)Magnified (b)Zoom

Environment Details

• Machine: Macbook Pro/Chromebook
• Browser: Version 124.0.6367.93 (Official Build) (arm64)
• Screen reader: Voiceover/ChromeVox
• Bug filling time: 15 mins