:root {
  color-scheme: light;
  --ink: #121725;
  --muted: #5b6475;
  --soft: #f4f7fb;
  --paper: #fffdf8;
  --panel: rgba(255, 255, 255, 0.78);
  --line: rgba(24, 32, 56, 0.12);
  --blue: #1f6feb;
  --cyan: #0aa7b8;
  --green: #2f9e44;
  --amber: #c47a11;
  --red: #d94848;
  --violet: #6542d8;
  --shadow: 0 24px 70px rgba(18, 23, 37, 0.12);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 18% 12%, rgba(31, 111, 235, 0.16), transparent 30%),
    radial-gradient(circle at 82% 3%, rgba(10, 167, 184, 0.18), transparent 26%),
    linear-gradient(180deg, #f9fbff 0%, #fffdf8 48%, #f4f7fb 100%);
  font-family: ui-serif, Georgia, Cambria, "Times New Roman", Times, serif;
  line-height: 1.65;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.42;
  background-image:
    linear-gradient(rgba(18, 23, 37, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(18, 23, 37, 0.035) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(180deg, black, transparent 76%);
  z-index: -1;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
}

button,
input,
select {
  font: inherit;
}

.page-shell {
  position: relative;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  background: rgba(255, 255, 255, 0.78);
  border-bottom: 1px solid var(--line);
}

.nav {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  letter-spacing: -0.03em;
  text-decoration: none;
}

.brand-mark {
  width: 36px;
  height: 36px;
  border: 1px solid rgba(31, 111, 235, 0.24);
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, #ffffff, #eaf2ff);
  color: var(--blue);
  box-shadow: 0 8px 24px rgba(31, 111, 235, 0.12);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-links a {
  text-decoration: none;
  color: var(--muted);
  padding: 9px 12px;
  border-radius: 999px;
  font-size: 0.95rem;
  transition: color 180ms ease, background 180ms ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--ink);
  background: rgba(31, 111, 235, 0.08);
}

.nav-cta {
  color: #ffffff !important;
  background: var(--ink) !important;
  box-shadow: 0 10px 25px rgba(18, 23, 37, 0.18);
}

.hero {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: 86px 0 72px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: start;
}

.hero-stack {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.hero-stack .abstract-hero + .framework-hero {
  margin-top: 64px;
}

.hero-stack .hero-card {
  align-self: stretch;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 7px 12px;
  border-radius: 999px;
  border: 1px solid rgba(31, 111, 235, 0.18);
  background: rgba(255, 255, 255, 0.72);
  color: var(--blue);
  font-weight: 700;
  font-size: 0.9rem;
}

.pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 8px rgba(47, 158, 68, 0.12);
}

.hero h1 {
  margin: 22px 0 16px;
  font-size: clamp(3rem, 7.5vw, 6.7rem);
  line-height: 1.12;
  letter-spacing: -0.075em;
}

.hero h1 span {
  display: block;
  padding-bottom: 0.08em;
  color: transparent;
  background: linear-gradient(110deg, var(--blue), var(--cyan) 42%, var(--ink));
  background-clip: text;
  -webkit-background-clip: text;
}

.subtitle {
  max-width: 680px;
  margin: 0 0 24px;
  color: var(--muted);
  font-size: clamp(1.08rem, 1.7vw, 1.3rem);
}

.authors {
  margin: 0 0 28px;
  color: #293044;
  font-size: 0.98rem;
}

.hero-actions,
.section-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 44px;
  padding: 11px 17px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.78);
  text-decoration: none;
  font-weight: 800;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 32px rgba(18, 23, 37, 0.13);
}

.btn.primary {
  color: #fff;
  background: linear-gradient(135deg, var(--ink), #283759);
  border-color: transparent;
}

.btn.accent {
  color: #fff;
  background: linear-gradient(135deg, var(--violet), var(--blue));
  border-color: transparent;
}

.btn.blue {
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--cyan));
  border-color: transparent;
}

.hero-card {
  position: relative;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(150deg, rgba(255, 255, 255, 0.85), rgba(235, 244, 255, 0.68));
  box-shadow: var(--shadow);
  overflow: hidden;
}

.hero-card::before {
  content: "";
  position: absolute;
  width: 240px;
  height: 240px;
  right: -74px;
  top: -70px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(31, 111, 235, 0.22), transparent 68%);
}

.framework-hero > *,
.abstract-hero > * {
  position: relative;
  z-index: 1;
}

.framework-hero-section + .framework-hero-section {
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.framework-hero h2,
.abstract-hero h2 {
  margin: 0 0 12px;
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  line-height: 1;
  letter-spacing: -0.055em;
}

.framework-hero .section-lede,
.abstract-hero .section-lede {
  margin: 0 0 16px;
}

.abstract-hero .section-lede {
  max-width: none;
}

.hero-framework-image {
  margin: 0 0 14px;
  padding: 8px;
}

.hero-process-list {
  gap: 8px;
}

.hero-process-list .process-item {
  padding: 10px;
  grid-template-columns: 34px 1fr;
  gap: 10px;
}

.hero-process-list .process-item b {
  width: 34px;
  height: 34px;
  border-radius: 12px;
}

.loop-diagram {
  position: relative;
  display: grid;
  gap: 16px;
}

.loop-center {
  min-height: 170px;
  border-radius: 26px;
  display: grid;
  place-items: center;
  text-align: center;
  color: #fff;
  background:
    linear-gradient(135deg, rgba(18, 23, 37, 0.92), rgba(31, 111, 235, 0.88)),
    linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.18));
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.18);
}

.loop-center strong {
  display: block;
  font-size: 2rem;
  letter-spacing: -0.05em;
}

.loop-center code {
  color: #d9f5ff;
}

.loop-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.loop-steps span {
  padding: 12px 8px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.7);
  text-align: center;
  font-size: 0.9rem;
  font-weight: 800;
  border: 1px solid rgba(31, 111, 235, 0.12);
}

.stats-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-top: 16px;
}

.stat {
  padding: 16px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.76);
  border: 1px solid var(--line);
}

.stat b {
  display: block;
  font-size: 1.7rem;
  letter-spacing: -0.06em;
}

.stat span {
  color: var(--muted);
  font-size: 0.86rem;
}

main {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto 84px;
}

.section {
  padding: 72px 0;
  scroll-margin-top: 84px;
}

.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 28px;
}

.kicker {
  margin: 0 0 10px;
  color: var(--blue);
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 0.78rem;
}

.section h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.6rem);
  line-height: 1;
  letter-spacing: -0.065em;
}

.section-lede {
  max-width: 680px;
  color: var(--muted);
  font-size: 1.08rem;
}

.grid-3,
.grid-4,
.grid-5 {
  display: grid;
  gap: 16px;
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

.grid-5 {
  grid-template-columns: repeat(5, 1fr);
}

.card {
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: var(--radius-md);
  padding: 22px;
  box-shadow: 0 16px 40px rgba(18, 23, 37, 0.07);
}

.card h3,
.card h4 {
  margin: 0 0 10px;
  letter-spacing: -0.035em;
  line-height: 1.1;
}

.card p {
  margin: 0;
  color: var(--muted);
}

.formula-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.formula-panel.single {
  grid-template-columns: 1fr;
}

.formula {
  font-size: clamp(1.4rem, 3vw, 2.4rem);
  letter-spacing: -0.06em;
  color: var(--ink);
  padding: 28px;
  background: #111827;
  color: #eef6ff;
  border-radius: var(--radius-lg);
  overflow: auto;
}

.level-card {
  position: relative;
  overflow: hidden;
  min-height: 250px;
}

.level-card::before {
  content: attr(data-level);
  position: absolute;
  right: -6px;
  top: -24px;
  font-size: 5rem;
  font-weight: 900;
  letter-spacing: -0.12em;
  color: rgba(31, 111, 235, 0.08);
}

.level-card .badge {
  display: inline-flex;
  padding: 5px 10px;
  border-radius: 999px;
  background: rgba(31, 111, 235, 0.1);
  color: var(--blue);
  font-size: 0.8rem;
  font-weight: 900;
  margin-bottom: 16px;
}

.level-card.boundary {
  border-color: rgba(101, 66, 216, 0.3);
  background: linear-gradient(160deg, rgba(255, 255, 255, 0.86), rgba(244, 240, 255, 0.74));
}

.framework-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
  gap: 24px;
  align-items: start;
}

.image-frame {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 12px;
  background: rgba(255, 255, 255, 0.8);
  box-shadow: var(--shadow);
}

.image-frame img {
  border-radius: 20px;
}

#taxonomy > .image-frame {
  width: min(600px, 100%);
  margin-inline: auto;
  padding: 6px;
}

#taxonomy > .image-frame img {
  border-radius: 14px;
}

.process-list {
  display: grid;
  gap: 12px;
}

.process-item {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 14px;
  align-items: start;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.72);
}

.process-item b {
  width: 42px;
  height: 42px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--ink);
}

.taxonomy-cards .card {
  min-height: 230px;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.taxonomy-cards .card:hover {
  transform: translateY(-4px);
  box-shadow: 0 24px 54px rgba(18, 23, 37, 0.12);
}

.branch-tag {
  display: inline-block;
  margin-bottom: 16px;
  color: #fff;
  background: var(--ink);
  border-radius: 999px;
  padding: 5px 10px;
  font-size: 0.78rem;
  font-weight: 900;
}

.browser {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.82);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.browser-controls {
  display: grid;
  grid-template-columns: 1fr 220px 160px;
  gap: 12px;
  padding: 18px;
  border-bottom: 1px solid var(--line);
  background: rgba(244, 247, 251, 0.82);
}

.browser-controls input,
.browser-controls select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
  padding: 12px 14px;
  color: var(--ink);
}

.paper-table {
  width: 100%;
  border-collapse: collapse;
}

.paper-table th,
.paper-table td {
  padding: 14px 18px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

.paper-table th {
  color: var(--muted);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: rgba(255, 255, 255, 0.72);
}

.paper-table a {
  font-weight: 900;
  text-decoration: none;
  color: var(--blue);
}

.level-pill {
  display: inline-flex;
  min-width: 42px;
  justify-content: center;
  border-radius: 999px;
  padding: 3px 9px;
  background: rgba(31, 111, 235, 0.1);
  color: var(--blue);
  font-weight: 900;
}

.empty-state {
  display: none;
  padding: 28px;
  color: var(--muted);
  text-align: center;
}

.roadmap-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.roadmap-card b {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--cyan));
}

.citation-panel {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  align-items: start;
}

pre {
  margin: 0;
  white-space: pre-wrap;
  overflow: auto;
  padding: 22px;
  border-radius: var(--radius-md);
  color: #e9f2ff;
  background: #111827;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.copy-card {
  display: grid;
  gap: 12px;
}

.copy-btn {
  cursor: pointer;
  border: 0;
}

.footer {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: 34px 0 50px;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.footer a {
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 600ms ease, transform 600ms ease;
}

.reveal.in-view {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 980px) {
  .hero,
  .framework-grid,
  .formula-panel,
  .citation-panel {
    grid-template-columns: 1fr;
  }

  .grid-5,
  .grid-4,
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .nav-links {
    display: none;
  }

  .browser-controls {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .hero {
    padding-top: 52px;
  }

  .grid-5,
  .grid-4,
  .grid-3,
  .loop-steps,
  .stats-strip {
    grid-template-columns: 1fr;
  }

  .section-head {
    display: block;
  }

  .paper-table,
  .paper-table tbody,
  .paper-table tr,
  .paper-table td {
    display: block;
  }

  .paper-table thead {
    display: none;
  }

  .paper-table tr {
    padding: 12px 0;
    border-bottom: 1px solid var(--line);
  }

  .paper-table td {
    border: 0;
    padding: 6px 18px;
  }

  .paper-table td::before {
    content: attr(data-label);
    display: block;
    color: var(--muted);
    font-size: 0.76rem;
    font-weight: 900;
    letter-spacing: 0.08em;
    text-transform: uppercase;
  }

  .footer {
    flex-direction: column;
  }
}