html.intro-activa,
html.intro-activa body { overflow: hidden; }

#intro {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: grid;
  place-items: center;
  overflow: hidden;
  background: rgba(7, 12, 16, .72);
  opacity: 1;
  transition: opacity 620ms cubic-bezier(.23, 1, .32, 1);
  isolation: isolate;
}

#intro::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(circle at 50% 44%, rgba(31, 191, 151, .12), transparent 34%),
    linear-gradient(115deg, rgba(9, 20, 22, .72), rgba(7, 13, 18, .42) 48%, rgba(9, 18, 21, .68));
  pointer-events: none;
}

.intro__velo {
  position: absolute;
  inset: 0;
  background: rgba(4, 10, 14, .34);
  backdrop-filter: blur(1.5px);
  pointer-events: none;
  transition: opacity 620ms ease;
}

#intro.intro--saliendo { opacity: 0; pointer-events: none; }
#intro.intro--saliendo .intro__velo { opacity: 0; }

.intro__escena {
  position: relative;
  width: min(82vw, 760px);
  display: flex;
  flex-direction: column;
  align-items: center;
  perspective: 900px;
  transform: translateY(-2vh);
  animation: intro-aparece 900ms cubic-bezier(.23, 1, .32, 1) both;
}

.intro__logo {
  position: relative;
  z-index: 2;
  display: block;
  width: min(68vw, 620px);
  height: auto;
  filter: drop-shadow(0 0 22px rgba(50, 219, 179, .16));
  opacity: 0;
  transform-origin: center center;
  backface-visibility: hidden;
  animation: intro-logo-in 1150ms 120ms cubic-bezier(.23, 1, .32, 1) forwards;
}

.intro__claim {
  position: relative;
  z-index: 2;
  margin: 1rem 0 0;
  color: rgba(233, 249, 243, .9);
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: clamp(.78rem, 1.35vw, 1.05rem);
  font-weight: 600;
  letter-spacing: .08em;
  text-align: center;
  text-shadow: 0 2px 18px rgba(0, 0, 0, .5);
  opacity: 0;
  animation: intro-claim-in 700ms 750ms ease forwards;
}

.intro__barrido {
  position: absolute;
  z-index: 3;
  top: -30%;
  width: 13%;
  height: 160%;
  opacity: 0;
  pointer-events: none;
  filter: blur(8px);
  background: linear-gradient(90deg, transparent, rgba(202, 255, 237, .9) 42%, rgba(101, 240, 199, .24) 58%, transparent);
  mix-blend-mode: screen;
  transform: skewX(-18deg) translateX(-720%);
}

.intro__barrido--entrada { animation: intro-barrido-derecha 900ms 650ms cubic-bezier(.23, 1, .32, 1) forwards; }
.intro__barrido--salida { animation: intro-barrido-izquierda 850ms 2850ms cubic-bezier(.23, 1, .32, 1) both; }

#intro.intro--cierre .intro__logo,
#intro.intro--cierre .intro__claim { animation: intro-desaparece 850ms cubic-bezier(.77, 0, .175, 1) forwards; }

.intro__saltar,
.intro__sonido {
  position: fixed;
  bottom: 1.5rem;
  z-index: 5;
  padding: .58rem .9rem;
  border: 1px solid rgba(115, 228, 189, .4);
  border-radius: 999px;
  color: rgba(235, 255, 247, .92);
  background: rgba(8, 27, 28, .68);
  box-shadow: 0 8px 30px rgba(0, 0, 0, .18);
  cursor: pointer;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .06em;
  transition: background 180ms ease, border-color 180ms ease, transform 160ms ease;
}
.intro__saltar { right: 1.5rem; }
.intro__sonido { left: 1.5rem; opacity: .78; }
.intro__saltar:hover,
.intro__sonido:hover { border-color: rgba(115, 228, 189, .85); background: rgba(12, 57, 48, .86); }
.intro__saltar:active,
.intro__sonido:active { transform: scale(.97); }
.intro__saltar:focus-visible,
.intro__sonido:focus-visible { outline: 2px solid #73e4bd; outline-offset: 3px; }

@keyframes intro-aparece { from { opacity: 0; transform: translateY(2vh) scale(.985); } to { opacity: 1; transform: translateY(-2vh) scale(1); } }
@keyframes intro-logo-in {
  0% { opacity: 0; transform: translateZ(-260px) scale(.28); filter: blur(9px) drop-shadow(0 0 4px rgba(50, 219, 179, 0)); }
  58% { opacity: .92; transform: translateZ(-24px) scale(.94); filter: blur(1.5px) drop-shadow(0 0 18px rgba(50, 219, 179, .12)); }
  100% { opacity: 1; transform: translateZ(0) scale(1); filter: blur(0) drop-shadow(0 0 22px rgba(50, 219, 179, .16)); }
}
@keyframes intro-claim-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
@keyframes intro-barrido-derecha { 0% { opacity: 0; transform: skewX(-18deg) translateX(-720%); } 18% { opacity: .9; } 82% { opacity: .8; } 100% { opacity: 0; transform: skewX(-18deg) translateX(720%); } }
@keyframes intro-barrido-izquierda { 0% { opacity: 0; transform: skewX(18deg) translateX(720%); } 18% { opacity: .85; } 82% { opacity: .7; } 100% { opacity: 0; transform: skewX(18deg) translateX(-720%); } }
@keyframes intro-desaparece { to { opacity: 0; transform: scale(.98); } }

@media (max-width: 640px) {
  .intro__escena { width: 92vw; }
  .intro__logo { width: 78vw; }
  .intro__claim { max-width: 86vw; line-height: 1.5; }
  .intro__saltar { right: 1rem; bottom: 1rem; }
  .intro__sonido { left: 1rem; bottom: 1rem; }
}

@media (prefers-reduced-motion: reduce) {
  #intro { display: none; }
  html.intro-activa,
  html.intro-activa body { overflow: auto; }
}