The “reduce motion” setting in the operating system should be respected

Problem/Motivation

If you have the setting to reduce the motion activated in your operating system (in macOS you have to tick the "reduce motion" toggle under settings->accessibility->display) you still have the animation to expand or collapse the navigation sidebar when pressing the button in the lower left corner. That collapse/expansion triggers a shift and animation of the entire screen. For people with vestibular disorder, hyper-vigilance, and other focus related disorders can potentially be a trigger. i’ve asked @charles belov and he confirmed and provided some more context:

I cannot speak for all people with animation issues. Here is my reality:

- I have been triggered for vestibular disorder with surprisingly small screen areas. I believe it has to do with whether I am focusing on that area.

- It's not just about vestibular disorder, it's about hypervigilance and other focus disorders. Any animation can potentially trigger hypervigilance or disrupt focus.

- Further, enough animation has triggered unwanted physical effects for me that any unsolicited animation can be emotionally triggering. I believe that issue has lessened now that I'm using the workaround below and feel I have more control, but again I can't speak for others.

So the best practice would be if people indicate they don't want animation, only give them essential animation, only with a play/pause button, then default to pause. No cosmetic animation.

As a side note, "Reduce motion" is an artifact of Apple getting there first and calling it that. Windows and Android use language indicating it's all or nothing, even if they don't always follow it.

in a followup he also added:

There may be a fine line between hypervigilance and ADHD, or it may not matter, but people with either one can find animations distracting. For me, one issue is that the animation takes my attention away from my intended task and I have to re-focus on the task, which has a similar, if hopefully smaller, cost as multitasking does.

Steps to reproduce

Proposed resolution

Change the CSS selector for the existing reduced-motion rule so that it affects both the toolbar and the page content when they're moved.

the settings of the user should be respected, as charles summed it up nicely:

So the best practice would be if people indicate they don't want animation, only give them essential animation, only with a play/pause button, then default to pause. No cosmetic animation.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet