* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  width: 100%;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.button {
  width: 235px;
  height: 77px;
  border-radius: 39px;
  border: none;
  background-color: tomato;
  display: inline-block;
  color: #222222;
  font-family: sans-serif;
  font-size: 24px;
  display: flex;
  justify-content: center;
  align-items: center;
  text-transform: uppercase;
  letter-spacing: 1.68px;
  cursor: pointer;
  transition: all .2s;
}

.button:hover {
  transition: all .2s;
  animation: shadow .6s infinite linear;
  background-color: tomato;
  color: #fff;
}

@keyframes shadow {
  0% {
    box-shadow: 0 0 10px 0px tomato, 0 0 10px 0px tomato; 
  }
  100% {
    box-shadow: 0 0 18px 6px rgba(255, 48, 26, 0), 0 0 4px 50px rgba(255, 48, 26, 0); 
  } 
}