I don\'t know how to use JQuery, so I need a method which could trigger an animation using JavaScript only.
I need to call/trigger CSS Animation when the user scrol
This is how you can use vanilla JavaScript to change/trigger an animation associated with an HTML element.
First, you define your animations in CSS.
@keyframes spin1 { 100% { transform:rotate(360deg); } }
@keyframes spin2 { 100% { transform:rotate(-360deg); } }
@keyframes idle { 100% {} }
Then you use javascript to switch between animations.
document.getElementByID('yourElement').style.animation="spin2 4s linear infinite";
Note: 'yourElement' is the target HTML element that you wish to animate.
For example: