/* ============================================================
   ANIMATIONS — Scroll Effects, Transitions, Keyframes
   ============================================================ */

/* ---- Scroll-triggered Reveal Animations ---- */

.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
  will-change: opacity, transform;
}

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

/* Staggered children */
.reveal-stagger > * {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-stagger.revealed > *:nth-child(1) { transition-delay: 0.05s; }
.reveal-stagger.revealed > *:nth-child(2) { transition-delay: 0.12s; }
.reveal-stagger.revealed > *:nth-child(3) { transition-delay: 0.19s; }
.reveal-stagger.revealed > *:nth-child(4) { transition-delay: 0.26s; }
.reveal-stagger.revealed > *:nth-child(5) { transition-delay: 0.33s; }
.reveal-stagger.revealed > *:nth-child(6) { transition-delay: 0.40s; }

.reveal-stagger.revealed > * {
  opacity: 1;
  transform: translateY(0);
}

/* ---- Specific Animation Variants ---- */

.reveal-fade {
  opacity: 0;
  transition: opacity 1s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-fade.revealed {
  opacity: 1;
}

.reveal-slide-left {
  opacity: 0;
  transform: translateX(-60px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-slide-left.revealed {
  opacity: 1;
  transform: translateX(0);
}

.reveal-slide-right {
  opacity: 0;
  transform: translateX(60px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-slide-right.revealed {
  opacity: 1;
  transform: translateX(0);
}

.reveal-scale {
  opacity: 0;
  transform: scale(0.9);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* ---- Parallax Layer ---- */

.parallax-container {
  overflow: hidden;
  position: relative;
}

.parallax-element {
  will-change: transform;
  transition: none; /* Parallax uses JS, no CSS transition */
}

/* ---- Hero Text Animation ---- */

.hero-line {
  overflow: hidden;
  padding-bottom: 0.15em; /* space for descenders (g, y, p, q) */
  margin-bottom: -0.15em;  /* compensate so layout stays tight */
}

.hero-line-inner {
  display: inline-block;
  transform: translateY(110%);
  transition: transform 0.9s cubic-bezier(0.16, 1, 0.3, 1);
}

.hero-line-inner.visible {
  transform: translateY(0);
}

.hero-line:nth-child(1) .hero-line-inner { transition-delay: 0.1s; }
.hero-line:nth-child(2) .hero-line-inner { transition-delay: 0.22s; }
.hero-line:nth-child(3) .hero-line-inner { transition-delay: 0.34s; }

/* ---- Counter / Stats Animation ---- */

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

.stat-value {
  animation: countUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  opacity: 0;
}

.revealed .stat-value:nth-child(1) { animation-delay: 0.1s; }
.revealed .stat-value:nth-child(2) { animation-delay: 0.25s; }
.revealed .stat-value:nth-child(3) { animation-delay: 0.4s; }

/* ---- Timeline Animation ---- */

.timeline-item {
  opacity: 0;
  transform: translateX(-40px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.timeline-item.revealed {
  opacity: 1;
  transform: translateX(0);
}

/* ---- Publication Card Animation ---- */

.pub-card {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.pub-card:nth-child(even) {
  transform: translateX(30px);
}

.pub-card:nth-child(odd) {
  transform: translateX(-30px);
}

.pub-card.revealed {
  opacity: 1;
  transform: translateX(0) translateY(0);
}

/* ---- Hero Background Logo Entrance ---- */

@keyframes heroLogoFadeIn {
  from {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.6) rotate(-8deg);
  }
  to {
    opacity: 0.10;
    transform: translate(-50%, -50%) scale(1) rotate(0deg);
  }
}

.hero-bg-logo {
  animation: heroLogoFadeIn 2.5s cubic-bezier(0.16, 1, 0.3, 1) 0.3s both;
  opacity: 0;
}

/* ---- Gradient Text Reveal (Apple-style) ---- */

.text-reveal-gradient {
  background-size: 200% 100%;
  background-position: 100% 0;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  background-image: linear-gradient(
    90deg,
    var(--text-primary) 50%,
    var(--text-tertiary) 50%
  );
  transition: background-position 1.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.text-reveal-gradient.revealed {
  background-position: 0 0;
}

/* ---- Smooth Scroll Behavior ---- */

html {
  scroll-behavior: smooth;
}

/* ---- Reduced Motion ---- */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .reveal,
  .reveal-fade,
  .reveal-slide-left,
  .reveal-slide-right,
  .reveal-scale,
  .reveal-stagger > *,
  .service-card-animated,
  .timeline-item,
  .pub-card,
  .hero-line-inner,
  .service-highlight-tag,
  .nav-mobile-menu .nav-link {
    opacity: 1 !important;
    transform: none !important;
  }

  .education-dot::after,
  .hero-bg-mesh {
    animation: none !important;
  }

  .gallery-lightbox-img {
    filter: none !important;
    transform: none !important;
  }

  .timeline::before {
    transform: scaleY(1) !important;
  }

  .about-image {
    clip-path: circle(75% at 50% 50%) !important;
  }
}

/* ---- Nav scroll state ---- */

.nav-bar {
  transition: background-color var(--transition-base),
              box-shadow var(--transition-base),
              backdrop-filter var(--transition-base);
}

.nav-bar.scrolled {
  box-shadow: var(--shadow-sm);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
}

/* ---- Button Hover Effects ---- */

.btn {
  position: relative;
  overflow: hidden;
  transition: transform var(--transition-fast),
              box-shadow var(--transition-fast);
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn:active {
  transform: translateY(0);
}

/* ---- Card Hover ---- */

.card {
  transition: transform var(--transition-base),
              box-shadow var(--transition-base),
              background-color var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

/* ---- Loading animation ---- */

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

.page-wrapper {
  animation: fadeInPage 0.5s ease forwards;
}

/* ---- Scroll Progress Indicator ---- */

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 1001;
  background: transparent;
  pointer-events: none;
}

.scroll-progress-bar {
  height: 100%;
  width: 0%;
  background: var(--accent-gradient);
  border-radius: 0 2px 2px 0;
  transition: width 0.1s linear;
}

/* ---- Animated Hero Gradient Mesh ---- */

@property --hero-angle {
  syntax: '<angle>';
  initial-value: 0deg;
  inherits: false;
}

@keyframes rotateHeroGradient {
  to { --hero-angle: 360deg; }
}

.hero-bg-mesh {
  position: absolute;
  inset: 0;
  opacity: 0.07;
  background: conic-gradient(
    from var(--hero-angle, 0deg) at 60% 40%,
    var(--accent),
    #a855f7,
    var(--accent),
    transparent,
    var(--accent)
  );
  filter: blur(80px);
  animation: rotateHeroGradient 20s linear infinite;
  pointer-events: none;
}