JSFiddle - React, Tailwind, and code Playground

HTML

<div id="DiamondCenter">
      <div id="triangle-topleft"></div>
	</div>

CSS

#DiamondCenter{
	position:fixed;
	top:2%;
	left:48%;
	 background: #24201a ;
	 height:40px;
	width:40px;
	-webkit-transform: rotate(45deg);	
-moz-transform: rotate(45deg);
-ms-transform: rotate(45deg);
-o-transform: rotate(45deg);
transform: rotate(45deg);
z-index:20 !important;
	}

#triangle-topleft{
     width: 0; 
  height: 0; 
  border-top: 40px solid gray; 
  border-right: 40px solid transparent;
    
}

JavaScript

$(window).scroll(function() {
      alert("bottom!");
   if($(window).scrollTop() >50) {
       alert("bottom!");
   }
});