html {
      scroll-behavior: smooth;
    }

body
{
 margin: 0;
      padding: 0;
      height: 100%;
      overflow: hidden;
      background: url('https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fi1.wp.com%2Fcodemyui.com%2Fwp-content%2Fuploads%2F2016%2F11%2Fpure-css-snow-animation.gif&f=1&nofb=1&ipt=9e77ceb19a69aa1a876b0dc85364996d125bc93767dcd314af7b389b08da11fb&ipo=images') no-repeat center center fixed;
      background-size: cover;
      overflow: auto; 
  
}