An accordion, like the one in the Collapse listing, is a stack of collapse panels with styled headers. Each .accordion-item holds an .accordion-header whose .accordion-button toggles an .accordion-collapse. Add data-bs-parent="#faq" to every collapse and opening one closes the others; omit it, as the listing does, and items stay open independently ("always open"). A closed item's button needs .collapsed and aria-expanded="false", or its chevron points the wrong way. .accordion-flush removes outer borders and rounded corners for edge-to-edge use.