Selection controls

Choosing the right control is a semantics decision:

• Switch, an effect applies immediately (a setting flips live).
• Checkbox, one or more independent options; effect applies on commit.
• Radio group, exactly one choice from 2–5 visible options.
• Dropdown, one choice from many, or when space is tight.

Rules

• A switch that requires “Save” to apply is a checkbox, don't fake instant behavior.
• Show a parent checkbox as indeterminate when children are partially selected.
• Radio and checkbox hit targets include the label, not just the control.
• Dropdowns keep the selected item marked with a check and close on Esc.