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

  background: radial-gradient(circle at center, #1a1a1a, #000000 70%);
}

/* ⚡ EFECTO ENERGÍA */
body::before {
  content: "";
  position: fixed; /* 🔥 clave para que no rompa scroll */
  width: 200%;
  height: 200%;
  top: -50%;
  left: -50%;

  background: repeating-linear-gradient(
    45deg,
    rgba(0,255,255,0.05) 0px,
    rgba(0,255,255,0.05) 2px,
    transparent 2px,
    transparent 20px
  );

  animation: energia 8s linear infinite;
  z-index: 0;
}

@keyframes energia {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* 🔥 SLIDER */
.slider {
  position: relative;
  width: 100%;
  height: 100vh;
  overflow: hidden;
}

/* SLIDES */
.slide {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;

  opacity: 0;
  transform: translateX(100%);
  transition: all 0.6s ease;

  /* 🔥 SOLUCIÓN */
  overflow-y: auto;
  padding-right: 10px;
}
.slide::-webkit-scrollbar {
  width: 6px;
}

.slide::-webkit-scrollbar-thumb {
  background: #00ffff; /* ⚡ Mercurio */
  border-radius: 10px;
}

.slide.active {
  opacity: 1;
  transform: translateX(0);
}

/* CONTENIDO */
.contenido {
  position: relative;
  z-index: 2;

  max-width: 800px;
  margin: auto;
  padding: 100px 20px 120px;
}

/* ⚡ SIMBOLO */
.simbolo {
  font-size: 120px;
  color: #00ffff;

  animation: vibrar 0.15s infinite alternate;

  text-shadow:
    0 0 10px #00ffff,
    0 0 20px #00ffff,
    0 0 40px #00ffff,
    0 0 80px #00ffff;
}

/* ⚡ VIBRACIÓN */
@keyframes vibrar {
  from { transform: translateX(-2px); }
  to   { transform: translateX(2px); }
}

/* TITULO */
h1 {
  font-size: 44px;
  margin: 20px 0;
}

/* TEXTO */
p {
  font-size: 18px;
  line-height: 1.8;
  color: #cceeff;
}

/* 🔙 BOTON VOLVER */
.volver {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);

  padding: 12px 25px;

  border: 1px solid #00ffff;
  color: #00ffff;
  text-decoration: none;

  transition: 0.3s;
  z-index: 1000;
}
.volver:hover {
  background: #9bbcff;
  color: black;
  box-shadow: 0 0 25px #9bbcff;
}

/* 🔥 FLECHAS */
.controles button {
  position: fixed;
  top: 50%;
  transform: translateY(-50%);

  background: transparent;
  border: 1px solid #00ffff;
  color: #00ffff;

  font-size: 30px;
  padding: 10px 15px;
  cursor: pointer;

  z-index: 1000;
  transition: 0.3s;
}

/* IZQ / DER */
#prev { left: 20px; }
#next { right: 20px; }

/* HOVER */
.controles button:hover {
  background: #00ffff;
  color: black;
  box-shadow: 0 0 25px #00ffff;
  transform: translateY(-50%) scale(1.1);
}

/* 📱 MOBILE */
@media (max-width: 768px) {

  body {
    overflow-y: auto;
  }

  .slider {
    height: auto;
  }

  .slide {
    position: relative;
    opacity: 1;
    transform: none;
  }

  .contenido {
    height: auto;
    overflow: visible;
    padding: 80px 15px 100px;
  }

  .simbolo {
    font-size: 80px;
  }

  h1 {
    font-size: 30px;
  }

  p {
    font-size: 16px;
  }

  /* 🚫 SACAMOS FLECHAS EN CELU */
  .controles {
    display: none;
  }
}