JSFiddle - React, Tailwind, and code Playground

HTML

<body onLoad="getRule()">
<div id="fundo">
<div id="ball1"></div>
</div>
</body>

CSS

#fundo{
    height: 100%;
    width: 100%;
    position: absolute;
}

#ball1{
    position: absolute;
    background-color: black;
    height: 50px;
    width: 50px;
      border-radius: 100%;
      animation-duration: 5s;
      animation-delay: 1s;
      animation-iteration-count: infinite;
	  animation-name: "voador";
}

@Keyframes ball1{

}

JavaScript

function getRule() {

      var rule;

      var ss = document.styleSheets;

      for (var i in ss) {

          // loop through all the rules!

          for (var x in ss[i].cssRules) {

              rule = ss[i].cssRules[x];

              if (rule.name === "voador" && rule.type === CSSRule.KEYFRAMES_RULE) {

                  var k = 100;
                  for(var j=0; j<101; j++){
                  ss[i].cssRules[x]..appendRule(j+"% { margin-left: " + k + "%; }");
                      k--;
                  }

                  return;
              }

          }

      }

  }