I got inspired by this website: https://brittanychiang.com/ especially the animations.
The ones which appear at the header when page is loaded are just typical css animations with delay or something. But when you scroll down and the another sections are visible the animation appears again and only once. Can you do it with pure CSS or you need to include JS?
Are you talking about the float-up animations on scroll? If yes, that can be done using CSS but might require some javascript as well based on your requirements to setup the animations. You can read more about it here.
Alternatively, you can use this as well to get your work done easily! However, since you want the animation to show up only once, you might have to make some changes using javascript.
