/*
 * Fadma — animations.css
 * Named, purposeful motion only. Every animation is a token consumer.
 * @media (prefers-reduced-motion: reduce) neutralises all of it at the bottom.
 */

/* ─────────────────────────────────────────────
   1. KEYFRAMES
───────────────────────────────────────────── */

@keyframes fadma-fade-up {
  from {
    opacity: 0;
    transform: translateY(28px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadma-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes fadma-slide-in-right {
  from {
    opacity: 0;
    transform: translateX(40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadma-slide-in-left {
  from {
    opacity: 0;
    transform: translateX(-40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadma-scale-up {
  from {
    opacity: 0;
    transform: scale(0.94);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes fadma-rule-grow {
  from { transform: scaleX(0); }
  to   { transform: scaleX(1); }
}

@keyframes fadma-progress-fill {
  from { width: 0; }
}

@keyframes fadma-drawer-in {
  from { transform: translateX(100%); }
  to   { transform: translateX(0); }
}

@keyframes fadma-overlay-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes fadma-back-top-pop {
  from {
    opacity: 0;
    transform: translateY(12px) scale(0.88);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* ─────────────────────────────────────────────
   2. SCROLL REVEAL — initial state + visible state
   JS adds .is-visible via IntersectionObserver
───────────────────────────────────────────── */

.scroll-reveal {
  opacity: 0;
  transform: translateY(28px);
  transition:
    opacity var(--t-dur-slow) var(--t-ease-out),
    transform var(--t-dur-slow) var(--t-ease-out);
}

.scroll-reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Staggered children — siblings get a delay cascade */
.scroll-reveal:nth-child(2) { transition-delay: 80ms; }
.scroll-reveal:nth-child(3) { transition-delay: 160ms; }
.scroll-reveal:nth-child(4) { transition-delay: 240ms; }
.scroll-reveal:nth-child(5) { transition-delay: 320ms; }
.scroll-reveal:nth-child(6) { transition-delay: 400ms; }

/* Variant: fade only (no vertical shift) */
.scroll-reveal--fade {
  transform: none;
}
.scroll-reveal--fade.is-visible {
  transform: none;
}

/* Variant: slide from left */
.scroll-reveal--left {
  transform: translateX(-40px);
}
.scroll-reveal--left.is-visible {
  transform: translateX(0);
}

/* Variant: slide from right */
.scroll-reveal--right {
  transform: translateX(40px);
}
.scroll-reveal--right.is-visible {
  transform: translateX(0);
}

/* Variant: scale */
.scroll-reveal--scale {
  transform: scale(0.94);
}
.scroll-reveal--scale.is-visible {
  transform: scale(1);
}

/* ─────────────────────────────────────────────
   3. HERO ENTRANCE (fires once on page load)
───────────────────────────────────────────── */

.hero__eyebrow {
  animation: fadma-fade-up var(--t-dur-slow) var(--t-ease-out) 100ms both;
}

.hero__title {
  animation: fadma-fade-up var(--t-dur-slow) var(--t-ease-out) 200ms both;
}

.hero__excerpt {
  animation: fadma-fade-up var(--t-dur-slow) var(--t-ease-out) 320ms both;
}

.hero__actions {
  animation: fadma-fade-up var(--t-dur-slow) var(--t-ease-out) 420ms both;
}

.hero__meta {
  animation: fadma-fade-in var(--t-dur-slow) var(--t-ease-out) 500ms both;
}

.hero__media {
  animation: fadma-scale-up 600ms var(--t-ease-out) 80ms both;
}

/* ─────────────────────────────────────────────
   4. HEADER SCROLL TRANSITION
   .scrolled class toggled by theme.js
───────────────────────────────────────────── */

.site-header {
  transition:
    background-color var(--t-dur-base) var(--t-ease-inout),
    backdrop-filter  var(--t-dur-base) var(--t-ease-inout),
    box-shadow       var(--t-dur-base) var(--t-ease-inout),
    padding-block    var(--t-dur-base) var(--t-ease-inout);
}

/* The .scrolled visual treatment is defined in layout.css;
   here we only ensure the transition is smooth. */

/* ─────────────────────────────────────────────
   5. CARD HOVER AFFORDANCES
   Lift + ruled underline on category label
───────────────────────────────────────────── */

.card {
  transition:
    transform  var(--t-dur-base) var(--t-ease-out),
    box-shadow var(--t-dur-base) var(--t-ease-out);
}

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

/* Card image zoom on hover */
.card__img {
  transition: transform 520ms var(--t-ease-out);
}

.card:hover .card__img {
  transform: scale(1.04);
}

/* Signature ruled line above .card__category — grows on hover */
.card__category::before {
  display: block;
  content: '';
  width: 2rem;
  height: 2px;
  background: var(--t-primary);
  margin-block-end: var(--t-space-2);
  transform-origin: left center;
  transition: transform var(--t-dur-base) var(--t-ease-out);
}

.card:hover .card__category::before {
  transform: scaleX(1.5);
}

/* ─────────────────────────────────────────────
   6. LINK UNDERLINE AFFORDANCE (signature detail)
   Animated underline on nav and body links
───────────────────────────────────────────── */

.site-nav__link {
  position: relative;
}

.site-nav__link::after {
  content: '';
  position: absolute;
  inset-inline-start: 0;
  bottom: -3px;
  width: 100%;
  height: 2px;
  background: var(--t-primary);
  transform: scaleX(0);
  transform-origin: right center;
  transition: transform var(--t-dur-base) var(--t-ease-out);
}

.site-nav__link:hover::after,
.site-nav__link.is-active::after {
  transform: scaleX(1);
  transform-origin: left center;
}

/* ─────────────────────────────────────────────
   7. BUTTON HOVER / FOCUS TRANSITIONS
───────────────────────────────────────────── */

.btn {
  transition:
    background-color var(--t-dur-fast) var(--t-ease-out),
    color            var(--t-dur-fast) var(--t-ease-out),
    border-color     var(--t-dur-fast) var(--t-ease-out),
    box-shadow       var(--t-dur-fast) var(--t-ease-out),
    transform        var(--t-dur-fast) var(--t-ease-out);
}

.btn:hover {
  transform: translateY(-1px);
}

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

/* ─────────────────────────────────────────────
   8. ICON BUTTON TRANSITIONS
───────────────────────────────────────────── */

.icon-btn {
  transition:
    color      var(--t-dur-fast) var(--t-ease-out),
    background var(--t-dur-fast) var(--t-ease-out),
    transform  var(--t-dur-fast) var(--t-ease-out);
}

.icon-btn:hover {
  transform: scale(1.1);
}

/* ─────────────────────────────────────────────
   9. MOBILE NAV DRAWER
───────────────────────────────────────────── */

.nav-drawer__panel {
  transition: transform var(--t-dur-base) var(--t-ease-inout);
}

.nav-overlay {
  transition: opacity var(--t-dur-base) var(--t-ease-out);
}

/* When open, the animation is handled by the transition above;
   initial state is set in layout.css (translateX(100%) / opacity:0) */

/* ─────────────────────────────────────────────
   10. SEARCH OVERLAY
───────────────────────────────────────────── */

.search-overlay {
  transition:
    opacity    var(--t-dur-base) var(--t-ease-out),
    visibility var(--t-dur-base) var(--t-ease-out);
}

.search-overlay__inner {
  transition: transform var(--t-dur-base) var(--t-ease-out);
  transform: translateY(-16px);
}

.search-overlay.is-open .search-overlay__inner {
  transform: translateY(0);
}

/* ─────────────────────────────────────────────
   11. BACK-TO-TOP BUTTON
───────────────────────────────────────────── */

.back-to-top {
  transition:
    opacity    var(--t-dur-base) var(--t-ease-out),
    visibility var(--t-dur-base) var(--t-ease-out),
    transform  var(--t-dur-base) var(--t-ease-out);
}

.back-to-top.is-visible {
  animation: fadma-back-top-pop var(--t-dur-base) var(--t-ease-out) both;
}

/* ─────────────────────────────────────────────
   12. PROGRESS BAR
───────────────────────────────────────────── */

.progress-bar {
  transition: width 80ms linear;
}

/* ─────────────────────────────────────────────
   13. DARK MODE COLOR TRANSITION
   Smooth palette swap when toggling theme
───────────────────────────────────────────── */

html {
  transition:
    background-color var(--t-dur-slow) var(--t-ease-inout),
    color            var(--t-dur-slow) var(--t-ease-inout);
}

/* ─────────────────────────────────────────────
   14. TOC LINK ACTIVE STATE
───────────────────────────────────────────── */

.toc__link {
  transition:
    color       var(--t-dur-fast) var(--t-ease-out),
    padding-inline-start var(--t-dur-fast) var(--t-ease-out),
    border-color var(--t-dur-fast) var(--t-ease-out);
}

/* ─────────────────────────────────────────────
   15. SECTION RULE GROW (signature detail on section titles)
───────────────────────────────────────────── */

.section__title::before {
  transform-origin: left center;
  /* The rule is defined in components.css; here we add the entrance */
}

.section__title.is-visible::before {
  animation: fadma-rule-grow 400ms var(--t-ease-out) both;
}

/* ─────────────────────────────────────────────
   16. FOOTER LINK HOVER
───────────────────────────────────────────── */

.site-footer__link {
  transition: color var(--t-dur-fast) var(--t-ease-out);
}

/* ─────────────────────────────────────────────
   17. BADGE / TAG HOVER
───────────────────────────────────────────── */

.badge,
.tag {
  transition:
    background-color var(--t-dur-fast) var(--t-ease-out),
    color            var(--t-dur-fast) var(--t-ease-out);
}

/* ─────────────────────────────────────────────
   18. SHARE BUTTON
───────────────────────────────────────────── */

.share__btn {
  transition:
    background-color var(--t-dur-fast) var(--t-ease-out),
    color            var(--t-dur-fast) var(--t-ease-out),
    transform        var(--t-dur-fast) var(--t-ease-out);
}

.share__btn:hover {
  transform: translateY(-2px);
}

/* ─────────────────────────────────────────────
   19. PROSE LINK UNDERLINE
───────────────────────────────────────────── */

.prose a {
  background-size: 0% 2px;
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-image: linear-gradient(var(--t-primary), var(--t-primary));
  transition: background-size var(--t-dur-base) var(--t-ease-out);
}

.prose a:hover {
  background-size: 100% 2px;
}

/* ─────────────────────────────────────────────
   20. PREFERS-REDUCED-MOTION — neutralise everything
───────────────────────────────────────────── */

@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;
  }

  .scroll-reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .hero__eyebrow,
  .hero__title,
  .hero__excerpt,
  .hero__actions,
  .hero__meta,
  .hero__media {
    animation: none;
    opacity: 1;
    transform: none;
  }

  .card:hover {
    transform: none;
  }

  .card:hover .card__img {
    transform: none;
  }

  .btn:hover {
    transform: none;
  }

  .icon-btn:hover {
    transform: none;
  }

  .share__btn:hover {
    transform: none;
  }

  html {
    transition: none;
  }
}