styles.css

body {
  background: #09111f;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
    Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

.button_su {
  overflow: hidden;
  position: relative;
  display: inline-block;
  border-radius: 20px;
  cursor: pointer;
}

.button_outer {
  border-radius: 1000px;
  position: absolute;
  left: 0;
  top: 0;
  width: 0px;
  height: 0px;
  margin-left: 0px;
  margin-top: 0px;
  pointer-events: none;
}

.button_inner {
  display: inline-block;
  background: #ff00e4;
  color: #f4f4f4;
  font-size: 16px;
  font-weight: normal;
  width: 132px;
  text-align: center;
  border-radius: 3px;
  transition: 400ms;
  text-decoration: none;
  padding: 22px;
  z-index: 100000;
}

.button_text {
  position: relative;
  z-index: 10000;
}

.expand-circle {
  animation: expand 0.5s forwards;
}

.collapse-circle {
  animation: collapse 0.5s forwards;
}

@keyframes expand {
  0% {
    width: 0px;
    height: 0px;
    margin-left: 0px;
    margin-top: 0px;
    background-color: rgba(42, 53, 80, 0.2);
  }
  100% {
    width: 400px;
    height: 400px;
    margin-left: -200px;
    margin-top: -200px;
    background-color: #cd113b;
  }
}

@keyframes collapse {
  0% {
    width: 400px;
    height: 400px;
    margin-left: -200px;
    margin-top: -200px;
    background-color: #cd113b;
  }
  100% {
    width: 0px;
    height: 0px;
    margin-left: 0px;
    margin-top: 0px;
    background-color: rgba(129, 80, 108, 0.6);
  }
}