body {
  margin: 0;
  font-family: sans-serif;
  color: #fff;
  text-align: center;

  background: radial-gradient(circle at center, #1a0010, #000000 70%);
  overflow-x: hidden;
  overflow-y: auto;
}

/* 🌑 SOMBRA */
body::before {
  content: "";
  position: absolute;
  width: 350px;
  height: 350px;

  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);

  background: radial-gradient(circle, rgba(255,0,100,0.2), transparent 70%);
  filter: blur(80px);

  animation: pulsar 5s infinite;
}

@keyframes pulsar {
  0% { transform: translate(-50%, -50%) scale(1); }
  50% { transform: translate(-50%, -50%) scale(1.2); }
  100% { transform: translate(-50%, -50%) scale(1); }
}

.contenido {
  position: relative;
  z-index: 2;

  max-width: 800px;
  margin: auto;
  padding: 100px 20px;
}

/* SIMBOLO */
.simbolo {
  font-size: 130px;
  color: #ff0077;

  animation: respirar 4s infinite;

  text-shadow:
    0 0 10px #ff0077,
    0 0 30px #ff0055,
    0 0 60px #990033;
}

@keyframes respirar {
  0% { transform: scale(1); }
  50% { transform: scale(1.1); }
  100% { transform: scale(1); }
}

/* TEXTO */
h1 {
  font-size: 44px;
}

p {
  font-size: 18px;
  line-height: 1.8;
}

/* BOTON */
.volver {
  display: inline-block;
  margin-top: 40px;
  padding: 12px 25px;

  border: 1px solid #ff0077;
  color: #ff0077;
  text-decoration: none;

  transition: 0.3s;
}

.volver:hover {
  background: #ff0077;
  color: black;
  box-shadow: 0 0 25px #ff0077;
}

/* RESPONSIVE */
@media (max-width: 768px) {
  .simbolo { font-size: 85px; }
  h1 { font-size: 30px; }
  p { font-size: 16px; }
}