:root {
  --color-fondo: #000000;
  --color-texto: #F0E6E0;
  --color-acento: #E8899A;
  --color-acento-claro: #1A0A0E;
  --color-dorado: #D4B88C;
  --color-overlay: rgba(0,0,0,0.85);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Montserrat', sans-serif;
  background: var(--color-fondo);
  color: var(--color-texto);
  font-weight: 500;
  letter-spacing: 0.03em;
}

section {
  padding: clamp(3rem, 10vw, 6rem) clamp(1rem, 4vw, 2rem);
  text-align: center;
  position: relative;
  content-visibility: auto;
  contain-intrinsic-size: auto 600px;
}

.seccion-titulo {
  font-family: 'Great Vibes', cursive;
  font-size: clamp(2.5rem, 8vw, 4rem);
  color: var(--color-acento);
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 400;
}

/* ==================== HERO ==================== */

#hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
  background: var(--color-fondo);
  padding-top: max(3rem, env(safe-area-inset-top));
  padding-bottom: 2rem;
  z-index: 2;
  content-visibility: visible;
}

#canvas-corazon {
  position: relative;
  width: 100%;
  height: 80dvh;
}

#fotos {
  background: var(--color-acento-claro);
  position: relative;
  z-index: 1;
}

.hero-titulo {
  position: relative;
  z-index: 2;
  font-family: 'Montserrat', sans-serif;
  color: var(--color-dorado);
  font-size: clamp(1.8rem, 6vw, 3rem);
  font-weight: 500;
  letter-spacing: 0.05em;
  animation: aparecer 2s ease-out;
  margin-bottom: 1rem;
  text-align: center;
}

.hero-dedicatoria {
  position: relative;
  z-index: 2;
  font-family: 'Montserrat', sans-serif;
  color: var(--color-texto);
  font-size: clamp(0.85rem, 2.2vw, 1rem);
  font-weight: 500;
  letter-spacing: 0.03em;
  animation: aparecer 2.5s ease-out;
  margin-bottom: 2rem;
  text-align: center;
  opacity: 0.9;
}

.hero-subtitulo {
  display: none;
}

@keyframes aparecer {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ==================== SWIPER / CARRUSEL ==================== */

.fotos-subtitulo {
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  color: var(--color-texto);
  font-style: italic;
  opacity: 0.8;
  margin-bottom: 2rem;
}

.swiper {
  max-width: 480px;
  width: 100%;
  margin: 0 auto;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 24px rgba(232,137,154,0.15);
}

.swiper-slide img {
  width: 100%;
  height: 380px;
  object-fit: cover;
  display: block;
}

.swiper-pagination-bullet {
  background: rgba(240,230,224,0.4) !important;
}

.swiper-pagination-bullet-active {
  background: var(--color-acento) !important;
}

.swiper-button-prev,
.swiper-button-next {
  color: var(--color-acento) !important;
}

.swiper-button-prev::after,
.swiper-button-next::after {
  font-size: 1.5rem !important;
}

/* ==================== CARTA ==================== */

#carta {
  background: var(--color-fondo);
}

.carta-contenido {
  max-width: 640px;
  margin: 0 auto;
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  line-height: 1.9;
  color: var(--color-texto);
}

.carta-contenido p {
  margin-bottom: 1.5rem;
}

.carta-firma {
  margin-top: 2rem;
  font-style: normal;
  color: var(--color-acento);
  font-weight: 500;
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-family: 'Great Vibes', cursive;
}

/* ==================== VIDEO ==================== */

#video-seccion {
  background: var(--color-acento-claro);
}

.video-hint {
  color: var(--color-acento);
  font-style: italic;
  font-size: clamp(1rem, 2vw, 1.15rem);
  margin-bottom: 2rem;
}

#formulario-clave {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
}

#input-clave {
  font-size: 1.5rem;
  text-align: center;
  letter-spacing: 0.3em;
  border: none;
  border-bottom: 2px solid var(--color-acento);
  background: transparent;
  width: 160px;
  color: var(--color-texto);
  outline: none;
  padding: 0.25rem 0;
  transition: border-color 0.3s;
  -webkit-appearance: none;
  appearance: none;
  border-radius: 0;
}

#input-clave:focus {
  border-bottom-color: var(--color-dorado);
}

#input-clave::placeholder {
  color: var(--color-acento);
  opacity: 0.4;
  letter-spacing: 0.3em;
}

#btn-desbloquear {
  font-size: 1.2rem;
  padding: 0.6rem 2.5rem;
  border: 2px solid var(--color-acento);
  background: var(--color-acento);
  color: #000;
  border-radius: 30px;
  cursor: pointer;
  transition: background 0.3s, color 0.3s;
  font-weight: 500;
  touch-action: manipulation;
}

#btn-desbloquear:hover {
  background: transparent;
  color: var(--color-acento);
}

#mensaje-error {
  color: var(--color-acento);
  font-size: 1rem;
  font-style: italic;
  margin-top: 0.25rem;
  animation: shake 0.4s ease;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25%  { transform: translateX(-6px); }
  50%  { transform: translateX(6px); }
  75%  { transform: translateX(-4px); }
}

.oculto {
  display: none;
}

:focus-visible {
  outline: 2px solid var(--color-dorado);
  outline-offset: 2px;
}

#video-contenedor {
  margin-top: 1rem;
}

#youtube-iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 12px;
  max-width: 640px;
  border: none;
  box-shadow: 0 4px 24px rgba(232,137,154,0.15);
}

.btn-video-link {
  display: inline-block;
  padding: 0.8rem 2rem;
  border: 2px solid var(--color-acento);
  background: var(--color-acento);
  color: #000;
  border-radius: 30px;
  text-decoration: none;
  font-size: clamp(0.9rem, 2vw, 1.1rem);
  font-weight: 500;
  transition: background 0.3s, color 0.3s;
}

.btn-video-link:hover {
  background: transparent;
  color: var(--color-acento);
}

/* ==================== RESPONSIVE ==================== */

@media (min-width: 768px) {
  section {
    max-width: 900px;
    margin: 0 auto;
  }

  .swiper {
    max-width: 560px;
  }

  .swiper-slide img {
    height: 520px;
  }

  .carta-contenido {
    font-size: 1.3rem;
    line-height: 2;
  }
}

@media (min-width: 1024px) {
  .swiper-slide img {
    height: 580px;
  }

  .swiper {
    max-width: 640px;
  }
}

@media (min-width: 1440px) {
  section {
    max-width: 1200px;
  }

  .swiper {
    max-width: 700px;
  }

  .swiper-slide img {
    height: 620px;
  }

  .carta-contenido {
    font-size: 1.4rem;
    line-height: 2.1;
    max-width: 720px;
  }

  .hero-titulo {
    font-size: 3.5rem;
  }
}