The Silly Mistake That's Making Your Popovers Turn Out Flat - Tasting Table
"Making sure your oven is really hot is the best tip. I'd recommend letting it stay preheated for at least 15 minutes before baking to ensure it will hold its temperature well."
Creating an Auto-Closing Notification With an HTML Popover | CSS-Tricks
The HTML popover attribute allows elements to become top-layer popups that can be triggered and managed using specific attributes such as popovertarget and popovertargetaction.