/* ==========================================================================
   ESCENA 4: MAR NOCTURNO Y CARTA INTERACTIVA
   ========================================================================== */

.ocean-scene-container {
  width: 100%;
  max-width: 580px;
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
}

/* --------------------------------------------------------------------------
   SOBRE FLOTANTE INTERACTIVO (ENVELOPE 3D)
   -------------------------------------------------------------------------- */
.floating-envelope-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.8rem;
  animation: floatOcean 4.5s ease-in-out infinite;
  perspective: 900px;
}

.interactive-envelope {
  width: 220px;
  height: 145px;
  background: #f6e8cc;
  position: relative;
  border-radius: 6px;
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.6), 0 0 25px rgba(246, 216, 155, 0.2);
  cursor: pointer;
  transform-style: preserve-3d;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.4s ease;
}

.interactive-envelope:active {
  transform: scale(0.97);
}

/* Solapa Superior 3D */
.envelope-flap {
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 0;
  border-left: 110px solid transparent;
  border-right: 110px solid transparent;
  border-top: 80px solid #ecd8b3;
  transform-origin: top;
  transition: transform 0.75s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 5;
}

.envelope-opened .envelope-flap {
  transform: rotateX(180deg);
  z-index: 1;
}

/* Bolsillo Inferior / Triángulos Laterales */
.envelope-pocket {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 0;
  border-left: 110px solid #dfca9f;
  border-right: 110px solid #dfca9f;
  border-bottom: 75px solid #d4be8f;
  border-top: 70px solid transparent;
  border-radius: 0 0 6px 6px;
  z-index: 4;
  pointer-events: none;
}

/* Hoja asomándose */
.envelope-letter-peek {
  position: absolute;
  bottom: 8px;
  left: 14px;
  right: 14px;
  height: 110px;
  background: #faf6ee;
  border-radius: 4px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  z-index: 2;
  transition: transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
  padding: 10px;
}

.letter-peek-lines {
  width: 70%;
  height: 4px;
  background: rgba(180, 160, 140, 0.4);
  border-radius: 2px;
  margin-bottom: 6px;
}

.envelope-opened .envelope-letter-peek {
  transform: translateY(-50px);
}

/* Sello de Corazón */
.envelope-seal {
  position: absolute;
  top: 60px;
  left: 50%;
  transform: translate(-50%, -50%);
  background: #d15886;
  color: #ffffff;
  border: 2px solid #f6e8cc;
  border-radius: var(--radius-full);
  padding: 0.35rem 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--font-pixel);
  font-size: 0.8rem;
  font-weight: 600;
  box-shadow: 0 4px 12px rgba(209, 88, 134, 0.5);
  z-index: 6;
  animation: gentlePulse 2s infinite ease-in-out;
  transition: opacity 0.3s ease;
}

.envelope-opened .envelope-seal {
  opacity: 0;
  pointer-events: none;
}

.envelope-hint {
  font-family: var(--font-pixel);
  font-size: 0.85rem;
  color: var(--accent-gold);
  letter-spacing: 0.05em;
  text-shadow: 0 0 10px rgba(246, 216, 155, 0.4);
}

/* --------------------------------------------------------------------------
   VISOR Y PAPEL DE LA CARTA (PAGINACIÓN Y ESTILO FÍSICO)
   -------------------------------------------------------------------------- */
.letter-reader {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: letterOpenUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.letter-paper-wrapper {
  width: 100%;
  max-width: 480px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.letter-paper {
  width: 100%;
  min-height: 380px;
  background: #fcf8f2;
  color: var(--paper-text);
  border-radius: var(--radius-md);
  padding: 2.2rem 1.8rem 1.4rem 1.8rem;
  box-shadow: 0 18px 45px rgba(0, 0, 0, 0.65), 0 0 0 1px rgba(180, 160, 140, 0.25);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  user-select: none;
  touch-action: pan-y;
}

/* Sello en la esquina del papel */
.letter-stamp {
  position: absolute;
  top: 1.1rem;
  right: 1.2rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  border: 1px dashed rgba(180, 130, 100, 0.5);
  border-radius: 4px;
  padding: 0.2rem 0.45rem;
  font-family: var(--font-pixel);
  font-size: 0.68rem;
  color: #a07855;
  background: rgba(246, 232, 204, 0.4);
}

.letter-stamp-icon {
  width: 12px;
  height: 12px;
}

/* Área de contenido de la página */
.letter-content-area {
  margin: 1.8rem 0 1.2rem 0;
  min-height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.letter-page {
  font-family: var(--font-letter);
  font-size: clamp(1.2rem, 4.2vw, 1.45rem);
  line-height: 1.7;
  color: #2b2520;
  text-align: left;
  opacity: 1;
  transform: translateX(0);
  transition: opacity 0.35s ease, transform 0.35s ease;
}

.letter-page.page-slide-left {
  opacity: 0;
  transform: translateX(-25px);
}

.letter-page.page-slide-right {
  opacity: 0;
  transform: translateX(25px);
}

/* Controles de Navegación de la Carta */
.letter-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding-top: 1rem;
  border-top: 1px solid var(--paper-line);
}

.letter-nav-btn {
  background: rgba(180, 160, 140, 0.15);
  border: 1px solid rgba(180, 160, 140, 0.3);
  color: #4a3e35;
  font-family: var(--font-pixel);
  font-size: 0.82rem;
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.letter-nav-btn:active:not(:disabled) {
  transform: scale(0.95);
  background: rgba(180, 160, 140, 0.3);
}

.letter-nav-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.letter-page-counter {
  font-family: var(--font-pixel);
  font-size: 0.78rem;
  color: #7a6b5e;
}

/* Botón de Finalizar Lectura */
.letter-finish-container {
  margin-top: 1.5rem;
  width: 100%;
  display: flex;
  justify-content: center;
  animation: fadeInSlow 0.6s ease-out;
}

.finish-letter-btn {
  width: 100%;
  max-width: 320px;
}

.btn-sparkle {
  font-size: 1.1rem;
}

/* Animaciones */
@keyframes floatOcean {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-10px) rotate(1deg); }
}

@keyframes letterOpenUp {
  0% { opacity: 0; transform: scale(0.85) translateY(30px); }
  100% { opacity: 1; transform: scale(1) translateY(0); }
}