:root {
  --bg: #f7f8f6;
  --bg-alt: #eeeeee;
  --ink: #242424;
  --muted: #666666;
  --muted-light: #898989;
  --navy: #0c6c3e;
  --navy-light: #145f3b;
  --gold: #fadb24;
  --gold-light: #ffe66b;
  --gold-soft: #fff3a6;
  --rust: #666666;
  --rust-light: #888888;
  --line: #d4d4d4;
  --line-light: #e5e5e5;
  --card-bg: #ffffff;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: Inter, system-ui, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .065;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='1.1' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  z-index: 8;
}
.wrap { width: min(1120px, calc(100% - 44px)); margin: 0 auto; }
.label {
  font-family: 'JetBrains Mono', monospace;
  text-transform: uppercase;
  letter-spacing: .12em;
  font-size: .65rem;
  font-weight: 500;
}

/* ─── HERO ─── */
.hero {
  background: var(--navy);
  color: #ffffff;
  overflow: hidden;
  position: relative;
  padding: 30px 0 72px;
}
.hero::after {
  content: "01";
  position: absolute;
  right: -20px;
  bottom: -60px;
  font: 800 clamp(12rem, 24vw, 22rem)/.8 'Playfair Display', serif;
  color: rgba(255,255,255,.045);
  letter-spacing: -.08em;
  pointer-events: none;
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 1;
}
.institution-logo { width: 162px; height: auto; display: block; }
.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  gap: 64px;
  align-items: center;
  padding-top: 82px;
  position: relative;
  z-index: 1;
}
.hero-kicker {
  font-family: 'JetBrains Mono', monospace;
  font-size: .72rem;
  letter-spacing: .13em;
  text-transform: uppercase;
  color: var(--gold-light);
  margin: 0 0 14px;
}
h1 {
  font: 800 clamp(3.4rem, 7vw, 7.2rem)/.86 'Playfair Display', serif;
  letter-spacing: -.065em;
  margin: 0 0 20px;
  max-width: 800px;
}
.hero-sub {
  font-size: 1.1rem;
  color: #e5f1e9;
  max-width: 540px;
  line-height: 1.5;
  margin: 0 0 30px;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.hero-meta span {
  padding: 8px 16px;
  border: 1px solid rgba(255,255,255,.2);
  border-radius: 0;
  font-size: .72rem;
  font-weight: 600;
  color: #eef8f1;
}
.hero-visual {
  display: grid;
  place-items: center;
  position: relative;
  min-height: 280px;
}
.hero-visual::before {
  content: "";
  position: absolute;
  width: 200px;
  height: 200px;
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 50%;
}
.hero-visual::after {
  content: "";
  position: absolute;
  width: 270px;
  height: 270px;
  border: 1px dashed rgba(255,255,255,.13);
  border-radius: 50%;
}
.hero-steps {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 16px;
  z-index: 1;
}
.hero-step {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 16px;
  background: rgba(255,255,255,.07);
  backdrop-filter: blur(2px);
}
.hero-step-num {
  font: 700 1.2rem 'Playfair Display', serif;
  color: var(--gold);
  width: 28px;
}
.hero-step-text {
  font-size: .78rem;
  font-weight: 600;
  color: #eef8f1;
}

/* ─── SECTION HEAD ─── */
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 30px;
  margin-bottom: 36px;
}
.section-head p {
  max-width: 380px;
  color: var(--muted);
  margin: 0;
  font-size: .88rem;
}
h2 {
  font: 700 clamp(2rem, 4.5vw, 4rem)/.95 'Playfair Display', serif;
  letter-spacing: -.05em;
  margin: 0;
}
h2 em { font-style: italic; }

/* ─── MAIN ─── */
main { padding: 76px 0; }

/* ─── TIMELINE ─── */
.filter {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 32px;
}
.filter button {
  border: 1px solid var(--line);
  padding: 9px 16px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font: 600 .76rem Inter, sans-serif;
  transition: .2s;
}
.filter button:hover { border-color: var(--gold); color: var(--ink); }
.filter button.active { background: var(--navy); color: #fff; border-color: var(--navy); }
.timeline { display: grid; gap: 20px; position: relative; }
.timeline::before {
  content: "";
  position: absolute;
  left: 55px;
  top: 30px;
  bottom: 30px;
  width: 1px;
  background: var(--line);
}
.timeline-item {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 28px;
  transition: opacity .4s, transform .4s;
}
.timeline-item.hidden {
  display: none;
}
.tl-marker {
  text-align: right;
  padding-top: 6px;
  position: relative;
}
.tl-marker::after {
  content: "";
  position: absolute;
  right: -15px;
  top: 18px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gold);
  border: 3px solid var(--bg);
  z-index: 1;
}
.timeline-item:nth-child(2) .tl-marker::after { background: var(--rust); }
.timeline-item:nth-child(3) .tl-marker::after { background: var(--navy); }
.tl-number {
  display: block;
  font: 800 3rem/.85 'Playfair Display', serif;
  letter-spacing: -.06em;
  color: var(--gold);
}
.tl-period {
  font-family: 'JetBrains Mono', monospace;
  font-size: .65rem;
  letter-spacing: .05em;
  color: var(--muted);
}
.tl-card {
  padding: 28px 32px;
  background: var(--card-bg);
  border-left: 4px solid var(--gold);
}
.timeline-item:nth-child(2) .tl-card { border-left-color: var(--rust); }
.timeline-item:nth-child(2) .tl-number { color: var(--rust); }
.timeline-item:nth-child(3) .tl-card { border-left-color: var(--navy); }
.timeline-item:nth-child(3) .tl-number { color: var(--navy); }
.tl-card h3 {
  font: 700 1.65rem/1.1 'Playfair Display', serif;
  letter-spacing: -.03em;
  margin: 0 0 10px;
}
.tl-card p { color: var(--muted); margin: 0 0 8px; font-size: .92rem; }
.tl-card p:last-of-type { margin-bottom: 0; }
.tl-card p strong { color: var(--ink); }
.tl-collapse {
  max-height: 0;
  overflow: hidden;
  transition: max-height .45s ease;
}
.tl-collapse.open {
  max-height: 600px;
}
.tl-collapse-inner {
  padding: 14px 16px;
  margin-top: 14px;
  background: var(--bg);
  font-size: .84rem;
  color: #3d3d3d;
  border-left: 3px solid var(--gold-light);
}
.tl-toggle {
  display: inline-block;
  background: none;
  border: 0;
  cursor: pointer;
  font-family: 'JetBrains Mono', monospace;
  font-size: .62rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--navy);
  padding: 6px 0 2px;
  margin-top: 4px;
  border-bottom: 1px dashed var(--line);
  user-select: none;
  transition: color .2s, border-color .2s;
}
.tl-toggle:hover { color: var(--gold); border-color: var(--gold); }
.tl-toggle::before { content: "+ "; }
.tl-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 16px;
}
.tl-tags span {
  padding: 5px 10px;
  font-size: .7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  background: var(--bg);
  color: var(--muted);
}

/* ─── BRIDGE ─── */
.bridge {
  margin: 84px 0;
  padding: 60px 0;
  background: var(--navy);
  color: #ffffff;
  position: relative;
  overflow: hidden;
}
.bridge::before {
  content: "\2753";
  position: absolute;
  right: 4%;
  top: -50px;
  font-size: 16rem;
  color: rgba(255,255,255,.06);
  line-height: 1;
}
.bridge-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  position: relative;
}
.bridge-kicker {
  font-family: 'JetBrains Mono', monospace;
  font-size: .7rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--gold-light);
  margin: 0 0 12px;
}
.bridge h2 { color: var(--gold-soft); }
.bridge blockquote {
  margin: 0;
  padding-left: 24px;
  border-left: 3px solid var(--gold);
  font: 600 italic 1.3rem/1.3 'Playfair Display', serif;
  color: #edf6ef;
}

/* ─── CONCEPTS ─── */
.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.concept-card {
  padding: 32px 24px;
  background: var(--card-bg);
  border-top: 5px solid var(--gold);
  position: relative;
}
.concept-card:nth-child(2) { border-top-color: var(--rust); }
.concept-card:nth-child(3) { border-top-color: var(--navy); }
.concept-num {
  font: 700 2.8rem/1 'Playfair Display', serif;
  color: var(--line);
  letter-spacing: -.05em;
}
.concept-tag {
  display: block;
  font-family: 'JetBrains Mono', monospace;
  font-size: .62rem;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--muted-light);
  margin: 8px 0 14px;
}
.concept-card h3 {
  font: 700 1.4rem/1.05 'Playfair Display', serif;
  letter-spacing: -.03em;
  margin: 0 0 10px;
}
.concept-card p { color: var(--muted); margin: 0; font-size: .86rem; }

/* ─── FLIPCARDS ─── */
.flip-section { margin-top: 80px; }
.flip-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.flip-card {
  perspective: 1200px;
  height: 300px;
  cursor: pointer;
}
.flip-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform .6s cubic-bezier(.4,0,.2,1);
  transform-style: preserve-3d;
}
.flip-card.flipped .flip-inner { transform: rotateY(180deg); }
.flip-front, .flip-back {
  position: absolute;
  inset: 0;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  padding: 26px 22px;
  border-radius: 2px;
  overflow-y: auto;
}
.flip-front {
  background: var(--card-bg);
  border-top: 5px solid var(--gold);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
}
.flip-card:nth-child(2) .flip-front { border-top-color: var(--rust); }
.flip-card:nth-child(3) .flip-front { border-top-color: var(--navy); }
.flip-card:nth-child(4) .flip-front { border-top-color: var(--gold); }
.flip-front .flip-icon {
  font: 700 2.2rem 'Playfair Display', serif;
  color: var(--line);
  letter-spacing: -.05em;
  margin-bottom: 14px;
}
.flip-front h3 {
  font: 700 1.1rem/1.1 'Playfair Display', serif;
  margin: 0 0 8px;
}
.flip-front p {
  font-size: .78rem;
  color: var(--muted);
  margin: 0;
}
.flip-hint {
  margin-top: 14px;
  font-family: 'JetBrains Mono', monospace;
  font-size: .6rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted-light);
}
.flip-back {
  background: var(--navy);
  color: #f0f7f2;
  transform: rotateY(180deg);
  text-align: left;
}
.flip-card:nth-child(2) .flip-back { background: var(--muted); }
.flip-card:nth-child(3) .flip-back { background: var(--navy-light); }
.flip-card:nth-child(4) .flip-back { background: #1a4a33; }
.flip-back h4 {
  font: 700 1rem 'Playfair Display', serif;
  margin: 0 0 10px;
  color: var(--gold-light);
}
.flip-back p {
  font-size: .8rem;
  line-height: 1.5;
  margin: 0;
  color: #e0efe5;
}

/* ─── CASE STUDY ─── */
.case-study {
  margin-top: 82px;
  display: grid;
  grid-template-columns: .8fr 1.2fr;
  gap: 0;
  background: var(--card-bg);
}
.case-intro {
  padding: 44px 36px;
  background: var(--navy);
  color: #ffffff;
}
.case-intro .label { color: var(--gold-light); margin-bottom: 16px; }
.case-intro h2 {
  color: var(--gold-soft);
  font-size: clamp(1.6rem, 2.8vw, 2.4rem);
}
.case-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 0 36px;
  padding-top: 36px;
  background: var(--card-bg);
}
.case-tab {
  border: 1px solid var(--line);
  background: transparent;
  padding: 10px 18px;
  cursor: pointer;
  font: 600 .78rem Inter, sans-serif;
  color: var(--muted);
  transition: .2s;
  flex-shrink: 0;
}
.case-tab:hover { border-color: var(--gold); color: var(--ink); }
.case-tab.active { background: var(--navy); color: #fff; border-color: var(--navy); }
.case-panels {
  padding: 24px 36px 44px;
  background: var(--card-bg);
}
.case-panel { display: none; }
.case-panel.active { display: block; animation: caseFade .35s ease; }
@keyframes caseFade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.case-panel h3 {
  font: 700 1.8rem/1.05 'Playfair Display', serif;
  letter-spacing: -.03em;
  margin: 0 0 16px;
}
.case-panel p { color: var(--muted); margin: 0 0 14px; font-size: .92rem; }
.case-panel p:last-child { margin-bottom: 0; }
.case-panel strong { color: var(--navy); }
.case-panel .highlight {
  display: inline-block;
  padding: 2px 8px;
  background: var(--gold-soft);
  font-weight: 700;
  color: var(--ink);
}

/* ─── REFLECTION ─── */
.reflection {
  margin-top: 80px;
  padding: 44px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.reflection h2 { margin-bottom: 30px; }
.reflection-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.reflection-item {
  padding: 24px;
  background: var(--card-bg);
  border: 1px solid var(--line-light);
}
.reflection-item .q-num {
  font: 700 1.1rem 'Playfair Display', serif;
  color: var(--gold);
  display: block;
  margin-bottom: 12px;
}
.reflection-item p { margin: 0; font-weight: 600; font-size: .93rem; }

/* ─── SCROLL PROGRESS ─── */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--line);
  z-index: 100;
}
.scroll-progress-bar {
  height: 100%;
  background: var(--gold);
  width: 0%;
  transition: width .1s;
}

/* ─── FOOTER / BIBLIOGRAPHY ─── */
footer {
  padding: 60px 0 64px;
  background: var(--bg-alt);
}
footer h2 {
  margin-bottom: 26px;
  font-size: clamp(1.8rem, 3.6vw, 3.2rem);
}
.bibliography {
  display: grid;
  gap: 10px;
  max-width: 880px;
}
.bibliography p {
  margin: 0;
  padding-left: 26px;
  text-indent: -26px;
  font-size: .84rem;
  color: #4d4d4d;
}
.bibliography em { font-style: italic; }
.bibliography a {
  color: var(--rust);
  text-decoration: underline;
  text-underline-offset: 2px;
}
.bibliography a:hover { color: var(--navy); }
.credit {
  margin-top: 30px;
  color: var(--muted);
  font-size: .76rem;
}

/* ─── REVEAL ─── */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: none; }
/* ─── RESPONSIVE ─── */
@media (max-width: 780px) {
  .wrap { width: min(100% - 28px, 600px); }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; padding-top: 50px; }
  .hero-visual { min-height: 200px; transform: scale(.7); transform-origin: left center; margin-bottom: -60px; }
  .hero { padding-bottom: 48px; }
  h1 { font-size: clamp(3rem, 13vw, 5rem); }
  .timeline-item { grid-template-columns: 1fr; gap: 8px; }
  .tl-marker { text-align: left; display: flex; align-items: baseline; gap: 10px; }
  .tl-marker::after { display: none; }
  .timeline::before { display: none; }
  .tl-number { font-size: 2.2rem; }
  .tl-card { padding: 20px; }
  .section-head { flex-direction: column; align-items: start; gap: 12px; }
  .section-head p { max-width: 100%; }
  .concept-grid { grid-template-columns: 1fr; }
  .flip-grid { grid-template-columns: 1fr 1fr; }
  .case-study { grid-template-columns: 1fr; }
  .case-tabs { padding: 24px 24px 0; overflow-x: auto; flex-wrap: nowrap; -webkit-overflow-scrolling: touch; }
  .case-tab { padding: 10px 14px; font-size: .72rem; }
  .case-panels { padding: 16px 24px 28px; }
  .case-intro, .case-body { padding: 28px 24px; }
  .bridge-content { grid-template-columns: 1fr; gap: 24px; }
  .reflection-grid { grid-template-columns: 1fr; }
  .quiz-item { padding: 18px 16px; }
}
@media (max-width: 520px) {
  .flip-grid { grid-template-columns: 1fr; }
  .flip-card { height: 260px; }
}