Shows elastic overscroll effects on non-root scroll containers. When a nested scrollable element reaches its scroll boundary, the overscroll affordance applies to that element instead of only the root scroller. This reduces the need for custom Javascript workarounds and can be controlled per element with overscroll-behavior.
Limiting elastic overscroll effects to the root scroller leads to the following issues: Abrupt boundaries in nested scrollers: Scrollable panels and iframes stop suddenly at their scroll limits even when the page root provides elastic boundary feedback. Custom workarounds: Developers who want native-feeling boundary feedback for inner scrollers build JavaScript-based overscroll effects, which are brittle and inconsistent across platforms. Inconsistent nested scrolling UI: The root scroller and inner scrollers behave differently on the same page, making nested scrolling harder to tune. Overscroll affordances remain controllable per element with overscroll-behavior.