Navbar not collapsed by default · Issue #19569 · twbs/bootstrap · GitHub
Elementor accordion closed by default using Javascript & CSS - MultiWebPress
Bootstrap Collapse - examples & tutorial
Bootstrap Collapse - examples & tutorial
Collapse · Bootstrap v5.0
Bootstrap Accordion Group
angularjs - angular ui-bootstrap accordion how to achieve customized behavior: default all close, when clicking one accordion-group heading, open all others - Stack Overflow
javascript - Bootstrap accordion not working. - Stack Overflow
Plus Minus icon with Bootstrap Accordion - Dheeraj Verma