JSFiddle - React, Tailwind, and code Playground

HTML

<div class="game-board"> 
   <div class="menu">Hello</div>
</div>

CSS

html{
    height:100%;
} 
body {
height: 100%;   

}

.game-board{
    background: #456;
    width: 1260px;
    height: 100%;
}

.menu{
  position: absolute;
  width: 400px;
  right: 0;
  top: 30%;
  left: 31%;
  background: whitesmoke;
  border-radius: 4px;

}