styles.css

main {
  background: #000000;
  color: #fff;
  font-family: sans-serif;
  height: 100%;
  left: 0;
  padding: 10px;
  position: fixed;
  text-align: center;
  top: 0;
  width: 100%;
}

section {
  margin: auto;
  width: 170px;
}

.btn {
  background: #a52df4;
  border: none;
  border-radius: 5px;
  color: white;
  padding: 10px;
  width: 80px;
}

.btn.btn-yes {
  display: block;
  position: fixed;
}

.btn.btn-no {
  position: absolute;
}

/* Coração pulsante */

.loading-heart {
  display: block;
  position: relative;
  width: 60px;
  height: 60px;
  margin: auto auto 30px auto;
  transform: rotate(45deg);
  transform-origin: 40px 40px;

}

.loading-heart span {

  top: 32px;
  left: 32px;
  position: absolute;
  width: 32px;
  height: 32px;
  background: #a52df4;
  animation: loading-heart 1.2s infinite cubic-bezier(0.215, 0.61, 0.355, 1);

}

.loading-heart span:after,
.loading-heart span:before {
  content: " ";
  position: absolute;
  display: block;
  width: 32px;
  height: 32px;
  background: #a52df4;
}

.loading-heart span:before {
  left: -24px;
  border-radius: 50% 0 0 50%;
}

.loading-heart span:after {
  top: -24px;
  border-radius: 50% 50% 0 0;
}
@keyframes loading-heart {

  0% {
    transform: scale(0.95);
  }
  5% {
    transform: scale(1.1);
  }
  39% {
    transform: scale(0.85);
  }
  45% {
    transform: scale(1);
  }
  60% {
    transform: scale(0.95);
  }
  100% {
    transform: scale(0.9);
  }
}