src/vs/platform/accessibility/browser/accessibilityService.ts/AccessibilityService/initReducedMotionListeners
class AccessibilityService:	private initReducedMotionListeners(reduceMotionMatcher: MediaQueryList) {

		if (!this._layoutService.hasContainer) {
			// we can't use `ILayoutService.container` because the application
			// doesn't have a single container
			return;
		}

		this._register(addDisposableListener(reduceMotionMatcher, 'change', () => {
			this._systemMotionReduced = reduceMotionMatcher.matches;
			if (this._configMotionReduced === 'auto') {
				this._onDidChangeReducedMotion.fire();
			}
		}));

		const updateRootClasses = () => {
			const reduce = this.isMotionReduced();
			this._layoutService.container.classList.toggle('reduce-motion', reduce);
			this._layoutService.container.classList.toggle('enable-motion', !reduce);
		};

		updateRootClasses();
		this._register(this.onDidChangeReducedMotion(() => updateRootClasses()));
	}