/* =============================================
   HOW-IT-WORKS — ENHANCED SCROLL ANIMATIONS
   Lightweight CSS-only animation definitions.
   Triggered by JS adding .visible class via IntersectionObserver.
   ============================================= */

/* --- Scroll progress indicator (child of navbar, sticks to its bottom) --- */
.scroll-progress {
  position: absolute;
  top: 100%;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--teal-400), var(--cyan-accent));
  width: 0%;
  z-index: 1;
  pointer-events: none;
}


/* --- Scale-in: for cards, badges, icons --- */
.scale-in {
  opacity: 0;
  transform: scale(0.85);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.scale-in.visible {
  opacity: 1;
  transform: scale(1);
}

/* --- Slide-up (subtle): for section headers --- */
.slide-up {
  opacity: 0;
  transform: translateY(25px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.slide-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Slide-left / Slide-right: for before/after columns --- */
.slide-left {
  opacity: 0;
  transform: translateX(-50px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.slide-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.slide-right {
  opacity: 0;
  transform: translateX(50px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.slide-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* --- Draw-border: for callout boxes --- */
.draw-border {
  border-color: transparent !important;
  transition: border-color 1s ease 0.3s;
}
.draw-border.visible {
  border-color: var(--border-teal-med) !important;
}

/* --- Glow-in: for highlight steps and important elements --- */
.glow-in {
  opacity: 0;
  transform: translateY(20px);
  box-shadow: 0 0 0 rgba(46, 196, 182, 0);
  transition: opacity 0.6s ease, transform 0.6s ease, box-shadow 0.8s ease 0.3s;
}
.glow-in.visible {
  opacity: 1;
  transform: translateY(0);
  box-shadow: 0 0 25px var(--glow-teal-subtle), 0 0 60px var(--glow-teal-nano);
}

/* --- Workflow timeline: line that draws itself --- */
.workflow-timeline {
  position: relative;
}
.workflow-timeline::before {
  content: '';
  position: absolute;
  left: 22px;
  top: 0;
  width: 3px;
  height: var(--tl-progress, 0%);
  background: linear-gradient(to bottom, var(--teal-400), var(--cyan-accent));
  border-radius: 2px;
  transition: height 0.15s linear;
  box-shadow: 0 0 8px var(--glow-teal-med);
  z-index: 1;
}

/* --- Workflow marker glow when visible --- */
.wf-step .wf-marker {
  transition: border-color 0.4s ease, box-shadow 0.4s ease, background 0.4s ease, color 0.4s ease;
}
.wf-step.visible .wf-marker {
  border-color: var(--teal-400);
  box-shadow: 0 0 12px var(--glow-teal);
}
.wf-step.highlight.visible .wf-marker {
  background: linear-gradient(135deg, var(--teal-400), var(--cyan-accent));
  color: var(--navy-900);
  border-color: var(--cyan-accent);
  box-shadow: 0 0 24px var(--glow-teal-strong);
}

/* --- Pipeline nodes: sequential reveal --- */
.pipe-node {
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.pipe-node:not(.visible) {
  opacity: 0;
  transform: translateY(15px) scale(0.9);
}
.pipe-node.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

/* --- Pipeline arrows: flowing dash animation --- */
.pipe-arrow {
  transition: opacity 0.4s ease;
}
.pipe-arrow:not(.visible) {
  opacity: 0;
}
.pipe-arrow.visible {
  opacity: 1;
  animation: arrowFlow 1.5s ease-in-out infinite;
}
@keyframes arrowFlow {
  0%, 100% { opacity: 0.4; transform: translateX(0); }
  50% { opacity: 1; transform: translateX(3px); }
}

/* --- Safety cards: sequential amber → green --- */
.safety-card {
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275),
              border-color 0.5s ease, box-shadow 0.5s ease;
}
.safety-card:not(.visible) {
  opacity: 0;
  transform: translateY(30px) scale(0.92);
}
.safety-card.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}
.safety-card.visible .safety-icon {
  animation: safetyPulse 0.6s ease-out;
}
@keyframes safetyPulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.2); }
  100% { transform: scale(1); }
}



/* --- Algo feature cards: subtle hover lift --- */
.algo-feature {
  transition: opacity 0.4s ease, transform 0.4s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}
.algo-feature:not(.visible) {
  opacity: 0;
  transform: translateY(18px);
}
.algo-feature.visible {
  opacity: 1;
  transform: translateY(0);
}
.algo-feature:hover {
  border-color: var(--border-teal-strong) !important;
  box-shadow: 0 4px 20px var(--glow-teal-faint);
  transform: translateY(-3px);
}

/* --- Compat cards: flip-style entrance --- */
.compat-card {
  transition: opacity 0.5s ease, transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.compat-card:not(.visible) {
  opacity: 0;
  transform: translateY(20px) scale(0.9);
}
.compat-card.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}
.compat-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 24px var(--border-teal-soft);
}

/* --- Equipment cards: bounce entrance --- */
.about-card {
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275), 
              border-color 0.3s ease, box-shadow 0.3s ease;
}
.about-card:not(.visible) {
  opacity: 0;
  transform: translateY(35px) scale(0.9);
}
.about-card.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}
.about-card:hover {
  border-color: var(--glow-teal-med);
  transform: translateY(-4px);
  box-shadow: 0 8px 32px var(--border-teal-soft);
}

/* --- Outcome columns: slide from sides --- */
.outcome-col.nhs {
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.outcome-col.nhs:not(.visible) {
  opacity: 0;
  transform: translateX(-40px);
}
.outcome-col.nhs.visible {
  opacity: 1;
  transform: translateX(0);
}

.outcome-col.private {
  transition: opacity 0.7s ease 0.15s, transform 0.7s ease 0.15s;
}
.outcome-col.private:not(.visible) {
  opacity: 0;
  transform: translateX(40px);
}
.outcome-col.private.visible {
  opacity: 1;
  transform: translateX(0);
}

/* --- Check marks in outcome lists: draw-in --- */
.outcome-col .check-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.3s ease;
}
.outcome-col:not(.visible) .check-mark {
  opacity: 0;
  transform: scale(0);
}
.outcome-col.visible .check-mark {
  opacity: 1;
  transform: scale(1);
}
.outcome-col.visible li:nth-child(1) .check-mark { transition-delay: 0.3s; }
.outcome-col.visible li:nth-child(2) .check-mark { transition-delay: 0.45s; }
.outcome-col.visible li:nth-child(3) .check-mark { transition-delay: 0.6s; }
.outcome-col.visible li:nth-child(4) .check-mark { transition-delay: 0.75s; }

/* --- Why-cards: staggered entrance --- */
.why-card {
  transition: opacity 0.6s ease, transform 0.6s ease, box-shadow 0.3s ease;
}
.why-card:not(.visible) {
  opacity: 0;
  transform: translateY(30px);
}
.why-card.visible {
  opacity: 1;
  transform: translateY(0);
}
.why-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 24px var(--shadow-card-light);
}

/* --- Detail steps: fast stagger --- */
.detail-step {
  transition: opacity 0.45s ease, transform 0.45s ease;
}
.detail-step:not(.visible) {
  opacity: 0;
  transform: translateY(20px);
}
.detail-step.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Compare-grid: before/after slide-in --- */
.compare-col.before {
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.compare-col.before:not(.visible) {
  opacity: 0;
  transform: translateX(-40px);
}
.compare-col.before.visible {
  opacity: 1;
  transform: translateX(0);
}

.compare-col.after {
  transition: opacity 0.7s ease 0.15s, transform 0.7s ease 0.15s;
}
.compare-col.after:not(.visible) {
  opacity: 0;
  transform: translateX(40px);
}
.compare-col.after.visible {
  opacity: 1;
  transform: translateX(0);
}

/* --- Section labels: the —— line is always visible (defined in style.css) --- */
.section-label {
  transition: opacity 0.5s ease, transform 0.5s ease;
}

/* --- Detail step time tags: glow on appear --- */
.ds-tag {
  transition: background 0.4s ease, box-shadow 0.4s ease;
}
.detail-step.visible .ds-tag {
  animation: tagGlow 1s ease-out;
}
@keyframes tagGlow {
  0% { box-shadow: 0 0 0 rgba(46, 196, 182, 0); }
  50% { box-shadow: 0 0 10px var(--glow-teal-med); }
  100% { box-shadow: 0 0 0 rgba(46, 196, 182, 0); }
}

/* --- Safety detail formulas: typewriter-like reveal --- */
.safety-detail {
  transition: opacity 0.5s ease 0.4s, transform 0.5s ease 0.4s;
}
.safety-card:not(.visible) .safety-detail {
  opacity: 0;
  transform: translateY(8px);
}
.safety-card.visible .safety-detail {
  opacity: 1;
  transform: translateY(0);
}

/* --- Cost summary box: border glow on appear --- */
#what-you-need .gap-callout,
[id='what-you-need'] > .container > div[style*='border-radius: 14px'] {
  transition: opacity 0.7s ease, transform 0.7s ease, box-shadow 0.8s ease 0.5s;
}
.visible[style*='border-radius: 14px'] {
  box-shadow: 0 0 30px var(--glow-teal-faint);
}

/* --- Card 3D tilt on hover (desktop only) --- */
@media (min-width: 769px) {
  .algo-feature,
  .why-card,
  .compat-card,
  .about-card {
    transform-style: preserve-3d;
    perspective: 800px;
  }
}

/* --- Gap callout: draw-border effect --- */
.gap-callout {
  transition: opacity 0.7s ease, transform 0.7s ease, border-color 0.8s ease 0.3s;
}
.gap-callout:not(.visible) {
  opacity: 0;
  transform: translateY(20px);
}
.gap-callout.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- CTA section pulse --- */
#hiw-cta .btn-primary {
  animation: ctaPulse 3s ease-in-out infinite;
}
@keyframes ctaPulse {
  0%, 100% { box-shadow: 0 0 0 0 var(--glow-teal-med); }
  50% { box-shadow: 0 0 20px 6px var(--glow-teal-subtle); }
}

/* --- Mobile: reduce complexity --- */
@media (max-width: 768px) {
  .slide-left, .slide-right,
  .compare-col.before, .compare-col.after,
  .outcome-col.nhs, .outcome-col.private {
    transform: translateY(30px) !important;
  }
  .slide-left.visible, .slide-right.visible,
  .compare-col.before.visible, .compare-col.after.visible,
  .outcome-col.nhs.visible, .outcome-col.private.visible {
    transform: translateY(0) !important;
  }
}

/* --- Frequency bar chart: grow from bottom --- */
.freq-bar {
  transform: scaleY(0);
  transform-origin: bottom center;
  opacity: 0;
  transition: transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.4s ease;
  transition-delay: var(--bar-delay, 0s);
}

.freq-bars.visible .freq-bar {
  transform: scaleY(1);
  opacity: 1;
}

/* =============================================
   REDUCED MOTION — WCAG 2.3.3 compliance
   Respects user's OS-level "reduce motion" setting.
   Disables all scroll-triggered transitions and
   continuous animations (parallax, arrow flow, etc.).
   Elements appear instantly without animation.
   ============================================= */
@media (prefers-reduced-motion: reduce) {
  /* Kill all transitions and animations globally */
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  /* Ensure scroll-triggered elements are immediately visible */
  .fade-in, .fade-in-left, .fade-in-right,
  .slide-up, .slide-left, .slide-right,
  .scale-in, .glow-in, .draw-border,
  .pipe-node, .pipe-arrow,
  .safety-card, .algo-feature, .compat-card, .about-card,
  .outcome-col, .why-card, .detail-step, .wf-step,
  .compare-col, .gap-callout, .freq-bars, .freq-bar {
    opacity: 1 !important;
    transform: none !important;
  }

  /* Disable hero parallax (JS-set transform) */
  .hero-content {
    transform: none !important;
    opacity: 1 !important;
  }

  /* Static timeline (no scroll-driven draw) */
  .workflow-timeline::before {
    height: 100% !important;
  }
}