Accordion. An accordion is used to show (and hide) HTML content. Use the w3-hide class to hide the accordion content.
When readers only need a few key pieces of information: If readers only need some information on a page, then an accordion can help them more easily and efficiently find the information they're looking for.
You can use any HTML element to open the accordion content. We prefer a button with a w3-block class, to span the entire width of the page (100% width).
Go to accordion item which you want to keep open, In Properties there is setting "StartsExpanded", Set it to True
Simple Accordion
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