/* ============================================================
   ArtVenture Zurich – animations.css
   Keyframes + scroll-reveal system
   ============================================================ */

/* ----------------------------------------------------------
   1. Keyframes
   ---------------------------------------------------------- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

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

@keyframes slideUp {
  from { opacity: 0; transform: translateY(100%); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes scrollLine {
  0%   { top: -100%; }
  50%  { top: 0%; }
  100% { top: 100%; }
}

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

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

@keyframes drawPath {
  from { stroke-dashoffset: 200; }
  to   { stroke-dashoffset: 0; }
}

/* ----------------------------------------------------------
   2. Scroll Reveal Base States
   ---------------------------------------------------------- */

/* Default: hidden, shifted down */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.75s var(--ease-out),
              transform 0.75s var(--ease-out);
}

/* Shift from left */
.reveal--left {
  opacity: 0;
  transform: translateX(-28px);
  transition: opacity 0.75s var(--ease-out),
              transform 0.75s var(--ease-out);
}

/* Shift from right */
.reveal--right {
  opacity: 0;
  transform: translateX(28px);
  transition: opacity 0.75s var(--ease-out),
              transform 0.75s var(--ease-out);
}

/* Fade only (no shift) */
.reveal--fade {
  opacity: 0;
  transform: none;
  transition: opacity 0.9s var(--ease-out);
}

/* Scale up slightly */
.reveal--scale {
  opacity: 0;
  transform: scale(0.97);
  transition: opacity 0.75s var(--ease-out),
              transform 0.75s var(--ease-out);
}

/* Visible state — applied by IntersectionObserver */
.reveal.is-visible,
.reveal--left.is-visible,
.reveal--right.is-visible,
.reveal--fade.is-visible,
.reveal--scale.is-visible {
  opacity: 1;
  transform: none;
}

/* ----------------------------------------------------------
   3. Stagger Delays (for sibling elements)
   ---------------------------------------------------------- */
.reveal-stagger > * {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.75s var(--ease-out),
              transform 0.75s var(--ease-out);
}

.reveal-stagger.is-visible > *:nth-child(1) { transition-delay: 0ms; }
.reveal-stagger.is-visible > *:nth-child(2) { transition-delay: 100ms; }
.reveal-stagger.is-visible > *:nth-child(3) { transition-delay: 200ms; }
.reveal-stagger.is-visible > *:nth-child(4) { transition-delay: 300ms; }
.reveal-stagger.is-visible > *:nth-child(5) { transition-delay: 400ms; }
.reveal-stagger.is-visible > *:nth-child(6) { transition-delay: 500ms; }

.reveal-stagger.is-visible > * {
  opacity: 1;
  transform: none;
}

/* ----------------------------------------------------------
   4. Delay Utilities (for individual reveals)
   ---------------------------------------------------------- */
.reveal-delay-1 { transition-delay: 100ms; }
.reveal-delay-2 { transition-delay: 200ms; }
.reveal-delay-3 { transition-delay: 300ms; }
.reveal-delay-4 { transition-delay: 400ms; }
.reveal-delay-5 { transition-delay: 500ms; }

/* ----------------------------------------------------------
   5. Loading State for Submit Button
   ---------------------------------------------------------- */
.btn--loading {
  position: relative;
  color: transparent !important;
  pointer-events: none;
}

.btn--loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 16px;
  height: 16px;
  margin: -8px 0 0 -8px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: var(--white);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

/* ----------------------------------------------------------
   6. Image Parallax Wrapper
   ---------------------------------------------------------- */
.parallax-wrap {
  overflow: hidden;
}

.parallax-img {
  will-change: transform;
}

/* ----------------------------------------------------------
   7. Hover Line Decorators
   ---------------------------------------------------------- */
.hover-underline {
  position: relative;
  display: inline-block;
}

.hover-underline::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: currentColor;
  transition: width var(--duration) var(--ease-out);
}

.hover-underline:hover::after {
  width: 100%;
}

/* ----------------------------------------------------------
   8. Language Transition Overlay
   ---------------------------------------------------------- */
.lang-transition-out {
  animation: fadeIn 0.15s ease reverse forwards;
}

.lang-transition-in {
  animation: fadeIn 0.25s ease forwards;
}

/* ----------------------------------------------------------
   9. Reduced Motion Override
   ---------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  .reveal,
  .reveal--left,
  .reveal--right,
  .reveal--fade,
  .reveal--scale {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .reveal-stagger > * {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn--loading::after {
    animation: none;
  }
}