/* ========================================
   我爱扬州 — 滚动动画与微交互
   ======================================== */

/* --- Scroll Reveal Base --- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* --- Direction Variants --- */
.reveal--left {
  transform: translateX(-30px);
}

.reveal--left.revealed {
  transform: translateX(0);
}

.reveal--right {
  transform: translateX(30px);
}

.reveal--right.revealed {
  transform: translateX(0);
}

.reveal--scale {
  transform: scale(0.92);
}

.reveal--scale.revealed {
  transform: scale(1);
}

/* --- Stagger Delays --- */
.reveal--delay-1 { transition-delay: 0.1s; }
.reveal--delay-2 { transition-delay: 0.2s; }
.reveal--delay-3 { transition-delay: 0.3s; }
.reveal--delay-4 { transition-delay: 0.4s; }
.reveal--delay-5 { transition-delay: 0.5s; }
.reveal--delay-6 { transition-delay: 0.6s; }

/* --- Parallax Background --- */
.parallax-bg {
  will-change: transform;
  transition: transform 0.1s linear;
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
  }

  .hero__background {
    animation: none;
  }

  .hero__eyebrow,
  .hero__title,
  .hero__subtitle,
  .hero__actions {
    opacity: 1;
    animation: none;
  }

  .hero__scroll {
    animation: none;
    opacity: 0.7;
  }

  .hero__scroll-icon::after {
    animation: none;
  }

  * {
    transition-duration: 0.01ms !important;
  }
}

/* --- Loading Skeleton --- */
.skeleton {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
}

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

/* --- Back to Top Button --- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: 0 4px 16px rgba(45, 156, 219, 0.4);
  cursor: pointer;
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--transition);
  z-index: 999;
  pointer-events: none;
}

.back-to-top.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--primary-dark);
  transform: translateY(-4px);
}

/* --- Fade In (general purpose) --- */
.fade-in {
  animation: fadeIn 0.6s ease forwards;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* --- Slide Up (general purpose) --- */
.slide-up {
  animation: slideUp 0.6s ease forwards;
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}