JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
 <head>
  <meta charset="utf-8">
  <meta name="viewport" content="width-device-width, initial-scale-1">
  <title>Background Color</title>
  <style>  
  body {
  background: linear-gradient(0deg, #2E2E2E, #FFFFFF);
  background-size: 1000% 1000%;
  }
</style>
<div class="container">
<a href="#" class="button25">Entries RSS</a>
</div>
 </head>
</html>

CSS

.container {
    display: flex;
    justify-content: center;
    align-items: center;
  }
a.button25 {
  position: relative;
  display: inline-block;
  width: 150px;
  height: 66px;
  line-height: 65px;
  vertical-align: middle;
  text-align: center;
  text-decoration: none;
  text-shadow: 0 -1px 1px #777;
  color: #fff;
  outline: none;
  border: 2px solid #9e9e9e;
  border-radius: 16px;
  box-shadow: 0 0 0 60px rgba(0,0,0,0) inset, .1em .1em .2em #fff;
  background: linear-gradient(#f7f7f7, #3b3b3b 48%, #242424 52%, #000000);
}
a.button25:active {
  top: .1em;
  left: .1em;
  box-shadow: 0 0 0 60px rgba(0,0,0,.05) inset;
}
.button25:before {
    position: absolute;
    top: 0;
    left: 0px;
    content: ".";
    color:transparent;
    line-height: 35px;
    width: 150px;
    margin-top: 0px;
    margin-bottom: 0px;
    margin-left: 0px;
    background-image: -webkit-linear-gradient(rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0.1) );
    background-image:-moz-linear-gradient(rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0.1));
    border-radius:16px; 
    display:block;
}