JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">

</div>

CSS

#container {
    position: absolute;
    width: 200px;
    height: 100px;
    left: calc(50vw - 105px);
    top: calc(50vh - 55px);
    animation: einfliegen 2s;
    border: 5px solid blue;
}
@keyframes einfliegen { 
  from { 
    left: 100vw;
  } 
  to { 
    left: calc(50vw - 105px) 
  } 
}