<h1>Pure CSS pulsing<br>button effect</h1>
<a class="button">Click Me</a>

/* ---------- Useful Button styling ---------- */

.button{
  position: relative;
  background-color: black;
  border-radius: 4em;
  font-size: 16px;
  color: white;
  padding: 0.8em 1.8em;
  cursor:pointer;
  user-select:none;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition-duration: 0.4s;
  -webkit-transition-duration: 0.4s; /* Safari */
}

.button:hover {
  transition-duration: 0.1s;
  background-color: #3A3A3A;
}

.button:after {
  content: "";
  display: block;
  position: absolute;
  border-radius: 4em;
  left: 0;
  top:0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: all 0.5s;
  box-shadow: 0 0 10px 40px white;
}

.button:active:after {
  box-shadow: 0 0 0 0 white;
  position: absolute;
  border-radius: 4em;
  left: 0;
  top:0;
  opacity: 1;
  transition: 0s;
}

.button:active {
  top: 1px;
}



/* ---------- Looking nice on CodePen ---------- */

@import url('https://fonts.googleapis.com/css2?family=Jost&display=swap');

html, body{
  height:100%;
  margin: 0;
}

body{
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-family: "Jost", sans-serif;
  font-size:14px;
  background-image: linear-gradient(to bottom right, #ffa578, #ff675a);
}

h1 {
  font-size: calc(1.5em + 3vw);
  margin: -2em 0 2em;
  text-align:center;
  line-height:1.3em;
}