Answers for "smooth scrollTo js"

smooth scroll css

html {
  scroll-behavior: smooth;
}

/* No support in IE, or Safari
You can use this JS polyfill for those */
http://iamdustan.com/smoothscroll/

how to smooth scroll in javascript

window.scrollTo({ top: 900, behavior: 'smooth' })

smooth-scroll.js

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/smooth-scroll/16.1.0/smooth-scroll.min.js"></script>