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Interaction Responsive Motion

Mobile Bottom Action Bar

Mobile Bottom Action Bar turns a frequent interface judgment into an executable constraint before generation.

mobileactionslayout

Design Principle

Critical mobile actions should be thumb-reachable without covering content, errors, or system navigation.

Principle Critical mobile actions should be thumb-reachable without covering content, errors, or system navigation.

Design action Pin primary action, secondary action, or price summary to the bottom safe area; add bottom padding and handle keyboard-open states.

Examples Positive example: Mobile checkout, detail purchase, form submit, filter apply, and multi-step flows. Counterexample: The sticky bottom bar covers the last form error.

Apply when Mobile checkout, detail purchase, form submit, filter apply, and multi-step flows. Users need to judge state, scope, risk, or next action quickly.

Source notes Source note: Synthesized from Apple HIG, Material Design, GOV.UK/Polaris/Atlassian component practices, and interaction accessibility principles.

Agent Directive

Pin primary action, secondary action, or price summary to the bottom safe area; add bottom padding and handle keyboard-open states.

Apply When

  • Mobile checkout, detail purchase, form submit, filter apply, and multi-step flows.
  • Users need to judge state, scope, risk, or next action quickly.

Avoid

  • The sticky bottom bar covers the last form error.
  • Irrelevant structure, copy, or decoration is added only to make the UI feel richer.

Knowledge Metadata

Category
Interaction Responsive Motion
Quality
85%
Version
v1
Published
6/6/2026