JSFiddle - React, Tailwind, and code Playground

HTML

Hello

CSS

@keyframes move-body-bg
{
    0% { background-position:left top; }
    50% { background-position:left bottom; }
    100% { background-position:left top; }
}

html,body
{
    margin: 0;
    padding: 0;
    height: 100%;
    background-image: url(http://www.placehold.it/800x2000);
    transition-property: background-position;
    
    -webkit-animation: move-body-bg 2s infinite; 
    -moz-animation:    move-body-bg 2s infinite; 
    -o-animation:      move-body-bg 2s infinite; 
    animation:         move-body-bg 2s infinite; 
}