/* ============================================================
   FAS7NY CASE STUDY
   ============================================================ */
:root {
  --bg: #EBEEF2;
  --surface: #FFFFFF;
  --surface-alt: #F5F7FA;
  --primary: #4338CA;
  --primary-lt: #6366F1;
  --primary-sub: rgba(67, 56, 202, .09);
  --text: #14171C;
  --text-2: #2D3441;
  --muted: #6B7480;
  --border: #D6DBE2;
  --border-hov: #B0BAC9;
  --ok: #16A34A;
  --danger: #DC2626;

  --font-disp: 'Fraunces', Georgia, serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 16px;
  --r-xl: 24px;
  --r-full: 9999px;

  --sh-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --sh-md: 0 4px 16px rgba(0,0,0,.08), 0 2px 4px rgba(0,0,0,.04);
  --sh-lg: 0 12px 40px rgba(0,0,0,.10), 0 4px 12px rgba(0,0,0,.05);
  --sh-xl: 0 24px 64px rgba(0,0,0,.12), 0 8px 24px rgba(0,0,0,.06);
  --sh-pri: 0 8px 28px rgba(67,56,202,.30);

  --t-fast: 150ms cubic-bezier(.4,0,.2,1);
  --t-base: 260ms cubic-bezier(.4,0,.2,1);
  --t-slow: 420ms cubic-bezier(.4,0,.2,1);

  --nav-h: 68px;
  --max-w: 1160px;
  --pad: clamp(1.25rem, 5vw, 2.5rem);
}

[data-theme="dark"] {
  --bg: #0D0F14;
  --surface: #161920;
  --surface-alt: #1C2030;
  --primary: #6366F1;
  --primary-lt: #818CF8;
  --primary-sub: rgba(99,102,241,.12);
  --text: #E8EBF0;
  --text-2: #C5CBD6;
  --muted: #8892A2;
  --border: #252A38;
  --border-hov: #353B50;
  --sh-sm: 0 1px 3px rgba(0,0,0,.25);
  --sh-md: 0 4px 16px rgba(0,0,0,.30);
  --sh-lg: 0 12px 40px rgba(0,0,0,.40);
  --sh-xl: 0 24px 64px rgba(0,0,0,.50);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 1rem);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  overflow-x: hidden;
  transition: background var(--t-base), color var(--t-base);
  -webkit-font-smoothing: antialiased;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1000;
  width: 0;
  height: 3px;
  background: var(--primary);
  box-shadow: 0 0 18px rgba(67,56,202,.35);
  pointer-events: none;
  transition: width 80ms linear;
}

a { color: inherit; text-decoration: none; }
img, video, svg { display: block; max-width: 100%; }
ul, ol { list-style: none; }
button { border: 0; background: none; color: inherit; font: inherit; cursor: pointer; }
strong { color: var(--text-2); font-weight: 650; }

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad);
}

.section-eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .74rem;
  font-weight: 500;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: .85rem;
}

.section-heading {
  font-family: var(--font-disp);
  font-size: clamp(1.9rem, 4vw, 2.75rem);
  font-weight: 500;
  line-height: 1.18;
  color: var(--text);
  letter-spacing: -.02em;
  margin-bottom: 3rem;
}
.section-heading em { color: var(--primary); font-style: italic; font-weight: 400; }

/* Navigation */
.nav {
  position: fixed;
  inset: 0 0 auto;
  height: var(--nav-h);
  z-index: 900;
  transition: background var(--t-base), box-shadow var(--t-base);
}

.nav.scrolled {
  background: rgba(235,238,242,.88);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  box-shadow: 0 1px 0 var(--border);
}
[data-theme="dark"] .nav.scrolled { background: rgba(13,15,20,.88); }

.nav__container {
  max-width: var(--max-w);
  height: 100%;
  margin: 0 auto;
  padding: 0 var(--pad);
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav__back,
.nav__brand,
.nav__link,
.theme-toggle {
  border-radius: var(--r-sm);
  transition: color var(--t-fast), background var(--t-fast), transform var(--t-fast);
}

.nav__back {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  font-size: .875rem;
  font-weight: 600;
  color: var(--muted);
  padding: .45rem .75rem;
}
.nav__back:hover { color: var(--primary); background: var(--surface-alt); transform: translateX(-2px); }

.nav__brand {
  display: inline-flex;
  align-items: baseline;
  gap: .5rem;
  padding: .4rem .65rem;
}
.nav__brand-mono {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
}
.nav__brand-ar {
  font-family: var(--font-disp);
  font-size: 1rem;
  color: var(--muted);
  font-style: italic;
}

.nav__links {
  display: flex;
  gap: .15rem;
  margin-left: auto;
}
.nav__link {
  display: block;
  font-size: .875rem;
  font-weight: 500;
  color: var(--muted);
  padding: .4rem .75rem;
}
.nav__link:hover, .nav__link.active { color: var(--text); background: var(--surface-alt); }

.theme-toggle {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  color: var(--muted);
  flex-shrink: 0;
}
.theme-toggle:hover { color: var(--text); background: var(--surface-alt); }
[data-theme="light"] .icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }

/* Buttons and utility controls */
.btn {
  position: relative;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  min-height: 42px;
  padding: .7rem 1.4rem;
  border-radius: var(--r-md);
  border: 1.5px solid transparent;
  font-size: .875rem;
  font-weight: 700;
  white-space: nowrap;
  transition: transform var(--t-fast), box-shadow var(--t-fast), background var(--t-fast), border-color var(--t-fast);
}
.btn--primary { background: var(--primary); color: #fff; border-color: var(--primary); box-shadow: var(--sh-pri); }
.btn--primary:hover { background: var(--primary-lt); border-color: var(--primary-lt); transform: translateY(-2px); }
.btn--secondary { color: var(--primary); border-color: var(--primary); }
.btn--secondary:hover { background: var(--primary-sub); transform: translateY(-2px); }
.ripple {
  position: absolute;
  border-radius: 50%;
  background: rgba(255,255,255,.35);
  transform: scale(0);
  animation: rippleAnim .5s linear;
  pointer-events: none;
}
@keyframes rippleAnim { to { transform: scale(4); opacity: 0; } }

.back-to-top {
  position: fixed;
  right: 2rem;
  bottom: 2rem;
  z-index: 500;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  box-shadow: var(--sh-md);
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: opacity var(--t-base), transform var(--t-base), background var(--t-fast), color var(--t-fast);
}
.back-to-top.visible { opacity: 1; transform: translateY(0); pointer-events: auto; }
.back-to-top:hover { background: var(--primary); color: #fff; }

/* Hero */
.cs-hero {
  min-height: 100svh;
  padding: calc(var(--nav-h) + 4rem) var(--pad) 5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--bg);
  position: relative;
  overflow: hidden;
}
.cs-hero::before {
  content: '';
  position: absolute;
  top: -220px;
  right: -220px;
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, var(--primary-sub) 0%, transparent 70%);
  pointer-events: none;
}

.cs-hero__container {
  width: min(100%, 980px);
  text-align: center;
  position: relative;
  z-index: 1;
}
.cs-hero__meta,
.cs-hero__chips,
.cta-card__actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: .55rem;
}
.cs-hero__meta { margin-bottom: 1.25rem; }
.cs-badge,
.chip,
.ptag,
.mtag {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  border-radius: var(--r-full);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 600;
  padding: .28rem .72rem;
}
.cs-badge { color: var(--primary); background: var(--primary-sub); border-color: rgba(67,56,202,.20); }
.cs-badge--green { color: var(--ok); background: rgba(22,163,74,.09); border-color: rgba(22,163,74,.22); }
.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ok);
  box-shadow: 0 0 0 3px rgba(22,163,74,.18);
  animation: statusPulse 2s ease-in-out infinite;
}
@keyframes statusPulse { 50% { box-shadow: 0 0 0 6px rgba(22,163,74,.08); } }

.cs-hero__title {
  display: flex;
  justify-content: center;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: .6rem;
}
.cs-hero__title-mono {
  font-family: var(--font-mono);
  font-size: clamp(3rem, 8vw, 6.2rem);
  font-weight: 700;
  letter-spacing: -.06em;
  line-height: .95;
}
.cs-hero__title-ar {
  font-family: var(--font-disp);
  font-size: clamp(2rem, 5vw, 4rem);
  color: var(--primary);
  font-style: italic;
  font-weight: 400;
}
.cs-hero__sub {
  color: var(--primary);
  font-weight: 700;
  letter-spacing: .02em;
  margin-bottom: 1rem;
}
.cs-hero__desc {
  max-width: 76ch;
  margin: 0 auto 1.75rem;
  color: var(--muted);
  font-size: 1.0625rem;
  line-height: 1.8;
}
.chip--hi,
.ptag--ai {
  color: var(--primary);
  background: var(--primary-sub);
  border-color: rgba(67,56,202,.22);
}

.cs-video {
  width: min(100%, 980px);
  margin-top: 3rem;
  position: relative;
  z-index: 1;
}
.cs-video__wrap {
  position: relative;
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  box-shadow: var(--sh-xl);
}
.cs-video__label {
  position: absolute;
  top: 1rem;
  left: 1rem;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: #fff;
  background: rgba(20,23,28,.68);
  border: 1px solid rgba(255,255,255,.18);
  border-radius: var(--r-full);
  padding: .28rem .7rem;
  backdrop-filter: blur(14px);
}
.cs-video__player {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: #0D0F14;
}

/* Stats and content sections */
.cs-stats,
.cs-section,
.cs-cta { padding: 6rem 0; }
.cs-section--alt,
.cs-stats,
.cs-cta { background: var(--surface-alt); }
.cs-section { background: var(--bg); }

.stats-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: .75rem;
}
.stat-item,
.problem-card,
.solution-card,
.module-card,
.stack-group,
.cta-card {
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--sh-md);
  transition: transform var(--t-base), box-shadow var(--t-base), border-color var(--t-base);
}
.stat-item {
  min-height: 124px;
  border-radius: var(--r-lg);
  padding: 1.15rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}
.stat-item:hover,
.module-card:hover,
.stack-group:hover {
  transform: translateY(-4px);
  box-shadow: var(--sh-lg);
  border-color: var(--border-hov);
}
.stat-item__val {
  font-family: var(--font-disp);
  font-size: clamp(1.15rem, 2vw, 1.55rem);
  color: var(--primary);
  line-height: 1.1;
  font-weight: 600;
}
.stat-item__lbl {
  color: var(--muted);
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.cs-section__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 380px;
  gap: 5rem;
  align-items: center;
}
.cs-section__grid--rev { grid-template-columns: 380px minmax(0, 1fr); }
.cs-section__grid--rev .cs-section__visual { order: -1; }
.cs-prose {
  display: flex;
  flex-direction: column;
  gap: 1.05rem;
  color: var(--text-2);
  font-size: .95rem;
  line-height: 1.85;
}

.problem-card,
.solution-card {
  border-radius: var(--r-xl);
  padding: 2rem;
  position: relative;
  overflow: hidden;
}
.problem-card::before,
.solution-card::before,
.module-card::before {
  content: '';
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: var(--primary);
  transform: scaleY(0);
  transform-origin: bottom;
  transition: transform var(--t-base);
}
.problem-card:hover::before,
.solution-card:hover::before,
.module-card:hover::before { transform: scaleY(1); }
.problem-card__title,
.solution-card__title {
  font-family: var(--font-disp);
  font-size: 1.3rem;
  font-weight: 500;
  margin-bottom: 1rem;
}
.problem-list { display: flex; flex-direction: column; gap: .75rem; }
.problem-item {
  display: flex;
  align-items: flex-start;
  gap: .65rem;
  color: var(--text-2);
  font-size: .9rem;
}
.problem-item svg { flex: 0 0 auto; margin-top: .22rem; }
.problem-item--bad svg { color: var(--danger); }
.problem-item--good svg { color: var(--ok); }

/* Architecture */
.arch-diagram {
  display: grid;
  grid-template-columns: 1fr 46px 1.2fr 46px 1.4fr 46px 1.2fr;
  align-items: center;
  gap: .35rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  padding: 2rem;
  box-shadow: var(--sh-lg);
}
.arch-col { min-width: 0; }
.arch-label-top {
  margin-bottom: .75rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  text-align: center;
}
.arch-col__nodes { display: grid; gap: .75rem; }
.arch-box {
  min-height: 94px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  transition: transform var(--t-fast), border-color var(--t-fast), background var(--t-fast);
}
.arch-box:hover { transform: translateY(-3px); border-color: var(--primary); background: var(--primary-sub); }
.arch-box__icon { font-size: 1.35rem; line-height: 1; margin-bottom: .45rem; }
.arch-box__name { font-family: var(--font-mono); font-size: .78rem; font-weight: 700; color: var(--text); }
.arch-box__sub { margin-top: .25rem; font-size: .68rem; color: var(--muted); }
.arch-box--app,
.arch-box--ai { border-color: rgba(67,56,202,.22); background: var(--primary-sub); }
.arch-connector {
  color: var(--border-hov);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
}
.arch-line-h { height: 1px; width: 32px; background: currentColor; }

/* Pipeline */
.pipeline {
  max-width: 900px;
  margin: 0 auto;
  display: grid;
  gap: 1rem;
}
.pipeline__step {
  display: grid;
  grid-template-columns: 70px 1fr;
  gap: 1rem;
  align-items: start;
}
.pipeline__num {
  height: 52px;
  display: grid;
  place-items: center;
  color: var(--primary);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  box-shadow: var(--sh-sm);
  font-family: var(--font-mono);
  font-weight: 700;
}
.pipeline__content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  padding: 1.5rem;
  box-shadow: var(--sh-md);
  transition: transform var(--t-base), box-shadow var(--t-base), border-color var(--t-base);
}
.pipeline__content:hover { transform: translateY(-3px); box-shadow: var(--sh-lg); border-color: var(--border-hov); }
.pipeline__icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  color: var(--primary);
  background: var(--primary-sub);
  border: 1px solid rgba(67,56,202,.2);
  border-radius: var(--r-md);
  margin-bottom: 1rem;
}
.pipeline__title {
  font-family: var(--font-disp);
  font-size: 1.2rem;
  font-weight: 500;
  margin-bottom: .55rem;
}
.pipeline__desc { color: var(--text-2); font-size: .9rem; line-height: 1.75; }
.pipeline__tags {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
}
.pipeline__arrow {
  width: 1px;
  height: 28px;
  background: var(--border);
  margin-left: 34px;
  position: relative;
}
.pipeline__arrow::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: -3px;
  border-left: 3.5px solid transparent;
  border-right: 3.5px solid transparent;
  border-top: 5px solid var(--border);
}

/* Modules and stack */
.modules-grid,
.stack-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}
.module-card {
  border-radius: var(--r-lg);
  padding: 1.65rem;
  position: relative;
  overflow: hidden;
}
.module-card__icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  color: var(--primary);
  background: var(--primary-sub);
  border: 1px solid rgba(67,56,202,.2);
  border-radius: var(--r-md);
  margin-bottom: 1.1rem;
}
.module-card__title {
  font-family: var(--font-disp);
  font-size: 1.12rem;
  font-weight: 500;
  margin-bottom: .55rem;
}
.module-card__desc {
  color: var(--muted);
  font-size: .875rem;
  line-height: 1.7;
  margin-bottom: 1.15rem;
}
.module-card__tech {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
}

.stack-grid { grid-template-columns: repeat(4, 1fr); }
.stack-group {
  border-radius: var(--r-lg);
  padding: 1.5rem;
}
.stack-group__title {
  font-family: var(--font-mono);
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 1rem;
}
.stack-items { display: grid; gap: .65rem; }
.stack-item {
  display: flex;
  flex-direction: column;
  gap: .15rem;
  padding: .75rem;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--surface-alt);
}
.stack-item--hi { background: var(--primary-sub); border-color: rgba(67,56,202,.22); }
.stack-item__name { color: var(--text); font-weight: 700; font-size: .9rem; }
.stack-item__role { color: var(--muted); font-size: .74rem; }

/* CTA and footer */
.cta-card {
  border-radius: var(--r-xl);
  padding: clamp(2rem, 5vw, 3rem);
  text-align: center;
}
.cta-card__title {
  font-family: var(--font-disp);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 500;
  margin-bottom: .75rem;
}
.cta-card__desc {
  color: var(--muted);
  max-width: 54ch;
  margin: 0 auto 1.5rem;
}

.footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 2rem 0;
}
.footer__inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: .8rem;
}
.footer__left { display: flex; align-items: center; gap: .55rem; flex-wrap: wrap; }
.footer__home { color: var(--primary); font-weight: 700; }
.footer__gh { color: var(--muted); transition: color var(--t-fast), transform var(--t-fast); }
.footer__gh:hover { color: var(--primary); transform: translateY(-2px); }

/* Motion */
[data-reveal] {
  opacity: 0;
  transition: opacity .65s cubic-bezier(.4,0,.2,1), transform .65s cubic-bezier(.4,0,.2,1);
}
[data-reveal="fade-up"] { transform: translateY(30px); }
[data-reveal="fade-left"] { transform: translateX(30px); }
[data-reveal].revealed { opacity: 1; transform: none; }
.page-out { animation: pageOutAnim .3s ease forwards; }
@keyframes pageOutAnim { to { opacity: 0; transform: translateY(-8px); } }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: .001ms !important;
  }
}

@media (max-width: 1080px) {
  .stats-grid { grid-template-columns: repeat(3, 1fr); }
  .arch-diagram {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .arch-connector {
    transform: rotate(90deg);
    height: 24px;
  }
  .arch-line-h { width: 24px; }
  .modules-grid { grid-template-columns: repeat(2, 1fr); }
  .stack-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 900px) {
  .nav__links { display: none; }
  .cs-section__grid,
  .cs-section__grid--rev {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .cs-section__grid--rev .cs-section__visual { order: 0; }
}

@media (max-width: 680px) {
  .cs-hero { padding-top: calc(var(--nav-h) + 2.5rem); }
  .cs-hero__title { flex-direction: column; align-items: center; gap: .35rem; }
  .stats-grid,
  .modules-grid,
  .stack-grid { grid-template-columns: 1fr; }
  .pipeline__step { grid-template-columns: 1fr; }
  .pipeline__num { width: 52px; }
  .pipeline__arrow { margin-left: 25px; }
  .footer__inner { flex-direction: column; text-align: center; }
  .footer__left { justify-content: center; }
  .back-to-top { right: 1rem; bottom: 1rem; }
}