:root {
  --bg: #f6f5f2;
  --bg-elevated: #ffffff;
  --text: #1c1c1a;
  --text-muted: #5c5a54;
  --border: #e2e0d8;
  --accent: #1e4d6b;
  --accent-soft: #e8f0f6;
  --accent-hover: #163a52;
  --shadow: 0 1px 2px rgba(28, 28, 26, 0.06), 0 8px 24px rgba(28, 28, 26, 0.06);
  --radius: 10px;
  --font-sans: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
  --font-serif: "IBM Plex Serif", Georgia, serif;
  --max-width: 720px;
  --max-width-wide: 1080px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(246, 245, 242, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.lang-switch {
  display: flex;
  align-items: center;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  background: var(--bg-elevated);
}

.lang-btn {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 0.35rem 0.55rem;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  line-height: 1.2;
}

.lang-btn:hover {
  color: var(--accent);
}

.lang-btn.active {
  background: var(--accent-soft);
  color: var(--accent);
}

.site-header--light .lang-switch {
  border-color: var(--light-border);
}

html[lang="zh-CN"] body {
  font-family: "Noto Sans SC", var(--font-sans);
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
}

.logo:hover {
  color: var(--accent);
  text-decoration: none;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
  font-size: 0.92rem;
}

.site-nav a {
  color: var(--text-muted);
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--accent);
}

.site-nav a.active {
  font-weight: 500;
}

main {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

/* Light theme (home, team, etc.) */

.page-light {
  --accent-gold: #b8924f;
  --accent-gold-soft: rgba(184, 146, 79, 0.12);
  --accent-glow: rgba(184, 146, 79, 0.28);
  --light-border: rgba(184, 146, 79, 0.28);
  --font-display: "Cormorant Garamond", var(--font-serif);
  color: var(--text);
  background: radial-gradient(ellipse 120% 80% at 50% -20%, #ffffff 0%, var(--bg) 58%);
  min-height: 100vh;
}

.page-light a {
  color: var(--accent);
}

.page-light a:hover {
  color: var(--accent-hover);
}

.light-backdrop {
  position: fixed;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  z-index: 0;
}

.grid-plane {
  position: absolute;
  inset: 0;
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 75%);
}

.grid-plane--light {
  opacity: 0.55;
  background-image:
    linear-gradient(rgba(30, 77, 107, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 77, 107, 0.06) 1px, transparent 1px);
}

.orbit {
  position: absolute;
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.orbit--light {
  border: 1px solid rgba(30, 77, 107, 0.1);
}

.orbit-a {
  width: min(90vw, 680px);
  height: min(90vw, 680px);
}

.orbit-b {
  width: min(70vw, 520px);
  height: min(70vw, 520px);
  border-style: dashed;
  opacity: 0.6;
}

.site-header--light {
  background: rgba(246, 245, 242, 0.92);
  border-bottom-color: var(--light-border);
  z-index: 20;
}

.site-header--light .logo {
  font-family: var(--font-display);
  font-size: 1.45rem;
}

.divider-gold--light {
  height: 1px;
  margin: 1.5rem auto;
  max-width: 280px;
  opacity: 0.55;
  background: linear-gradient(
    90deg,
    transparent 0%,
    var(--accent-gold) 20%,
    var(--accent-gold) 80%,
    transparent 100%
  );
}

.home-stage {
  position: relative;
  z-index: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem 1.5rem 3.5rem;
  min-height: calc(100vh - 8rem);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.home-portico {
  text-align: center;
  padding: 2rem 0;
}

.page-light .epigraph {
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin: 0 0 1.25rem;
  color: var(--accent);
  font-style: italic;
}

.phrase-banner {
  margin: 0 auto 2rem;
  max-width: 28rem;
  min-height: 2.25rem;
}

.page-light .phrase-line {
  font-family: var(--font-display);
  font-size: clamp(1rem, 2.2vw, 1.2rem);
  line-height: 1.5;
  color: var(--text-muted);
  font-style: italic;
  margin: 0;
  text-align: center;
  letter-spacing: 0.04em;
}

.phrase-text {
  transition: opacity 0.3s ease;
}

.page-light .phrase-cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  margin-left: 2px;
  vertical-align: text-bottom;
  background: var(--accent-gold);
  opacity: 0.85;
  animation: cursor-blink 1s step-end infinite;
}

@keyframes cursor-blink {
  50% {
    opacity: 0;
  }
}

.home-portico .home-actions {
  margin-bottom: 0;
}

.home-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.85rem;
}

.page-light .title-display {
  font-family: var(--font-display);
  font-size: clamp(3.5rem, 12vw, 5.5rem);
  line-height: 1;
  margin: 0 0 1.25rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  background: linear-gradient(165deg, #1e4d6b 0%, var(--accent-gold) 55%, #8a6d3b 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 2px 16px rgba(184, 146, 79, 0.2));
}

.page-light .btn--glow {
  background: linear-gradient(180deg, #e0c078 0%, #b8924f 100%);
  color: #1a1208;
  border: 1px solid rgba(255, 255, 255, 0.35);
  box-shadow: 0 0 20px var(--accent-glow);
  font-weight: 600;
}

.page-light .btn--glow:hover {
  background: linear-gradient(180deg, #ecd08a 0%, #c9a052 100%);
  color: #1a1208;
  text-decoration: none;
  box-shadow: 0 0 28px var(--accent-glow);
}

.site-footer--light {
  position: relative;
  z-index: 1;
  border-top-color: var(--light-border);
  background: rgba(255, 255, 255, 0.65);
}

.footer-rule--light {
  width: 120px;
  height: 1px;
  margin: 0 auto 0.75rem;
  opacity: 0.45;
  background: linear-gradient(
    90deg,
    transparent,
    var(--accent-gold),
    transparent
  );
}

.footer-sep {
  margin: 0 0.5rem;
  opacity: 0.4;
}

.footer-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  margin-top: 0.4rem !important;
}

/* Subpages (light theme) */

.subpage-title--light {
  background: linear-gradient(165deg, #1e4d6b 0%, var(--accent-gold) 55%, #8a6d3b 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* Subpages shared layout */

.subpage-stage {
  position: relative;
  z-index: 1;
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 2rem 1.5rem 3.5rem;
}

.subpage-header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.subpage-title {
  font-family: var(--font-display);
  font-size: clamp(2.25rem, 5vw, 3rem);
  line-height: 1.15;
  margin: 0;
  font-weight: 600;
}

/* Subpages */

.page-header {
  margin-bottom: 2rem;
}

.page-header h1 {
  font-family: var(--font-serif);
  font-size: 2rem;
  margin: 0 0 0.5rem;
  font-weight: 600;
}

.section {
  margin-bottom: 3rem;
}

.section h2 {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  margin: 0 0 0.75rem;
  font-weight: 600;
}

.section-intro {
  color: var(--text-muted);
  max-width: 40rem;
  margin: 0;
}

.page-kicker {
  margin: 0 0 0.35rem;
  color: var(--accent);
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.btn {
  display: inline-block;
  padding: 0.55rem 1.1rem;
  border-radius: 6px;
  font-size: 0.92rem;
  font-weight: 500;
  text-decoration: none;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  text-decoration: none;
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text);
  border-color: var(--border);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
  box-shadow: var(--shadow);
}

.setup-panel {
  margin-bottom: 1.25rem;
}

.setup-panel h2,
.setup-card h2 {
  font-size: 1.1rem;
  margin: 0 0 0.45rem;
}

.setup-panel h3,
.setup-card h3 {
  font-size: 0.95rem;
  margin: 0 0 0.35rem;
}

.setup-panel p,
.setup-card p {
  color: var(--text-muted);
  margin: 0;
}

.setup-panel-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

.setup-steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.75rem;
}

.setup-step {
  min-width: 0;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fbfaf7;
  padding: 0.95rem;
}

.setup-step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.55rem;
  height: 1.55rem;
  margin-bottom: 0.6rem;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
}

.setup-step a {
  display: inline-block;
  max-width: 100%;
  margin-top: 0.55rem;
  overflow-wrap: anywhere;
  font-size: 0.86rem;
  font-weight: 500;
}

.setup-note {
  margin-top: 0.55rem !important;
  font-size: 0.88rem;
}

.setup-checklist {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.55rem;
  margin: 0.95rem 0 0.75rem;
}

.setup-checklist span {
  display: flex;
  align-items: center;
  min-height: 2.5rem;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  background: #fbfaf7;
  color: var(--text);
  font-size: 0.88rem;
  font-weight: 500;
}

.setup-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.setup-card ol {
  margin: 0.65rem 0 0;
  padding-left: 1.25rem;
  color: var(--text-muted);
}

.setup-card li + li {
  margin-top: 0.35rem;
}

.setup-card code,
.setup-panel code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 4px;
  padding: 0.08rem 0.28rem;
}

.code-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
  margin: 0.8rem 0 0.75rem;
}

.code-grid pre {
  margin: 0;
  padding: 0.75rem;
  overflow: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fbfaf7;
}

.code-grid code {
  background: transparent;
  color: var(--text);
  padding: 0;
}

.doc-group {
  margin-bottom: 2rem;
}

.doc-group h2 {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 0.75rem;
  color: var(--text-muted);
}

.doc-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.5rem;
}

.doc-list a {
  display: block;
  padding: 0.85rem 1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
}

.doc-list a:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
  text-decoration: none;
}

.doc-list .doc-title {
  font-weight: 500;
  display: block;
}

.doc-list .doc-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  display: block;
  margin-top: 0.15rem;
}

.terms-list {
  display: grid;
  gap: 1rem;
}

.terms-item h2 {
  font-size: 1.05rem;
  margin: 0 0 0.35rem;
}

.terms-item p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem;
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.site-footer p {
  margin: 0.25rem 0;
}

.skeleton-note {
  font-size: 0.88rem;
  color: var(--text-muted);
  font-style: italic;
  margin-top: 1rem;
}

@media (prefers-reduced-motion: reduce) {
  .phrase-cursor {
    animation: none;
    display: none;
  }
}

@media (max-width: 640px) {
  .site-nav {
    font-size: 0.85rem;
    gap: 0.5rem 1rem;
  }

  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .header-left {
    width: 100%;
    justify-content: space-between;
  }

  .home-stage {
    padding-top: 1.5rem;
    min-height: calc(100vh - 10rem);
  }

  .setup-panel-head,
  .setup-grid,
  .code-grid,
  .setup-checklist {
    grid-template-columns: 1fr;
  }

  .setup-panel-head {
    display: grid;
  }

  .setup-panel-head .btn {
    justify-self: start;
  }

  .setup-steps {
    grid-template-columns: 1fr;
  }
}

/* Home — reasoning manuscript */

.page-home {
  --home-ink: #173a4a;
  --home-ink-deep: #0f2c38;
  --home-ocean: #285d70;
  --home-gold: #b78b46;
  --home-gold-light: #d8ba7b;
  --home-paper: #f0eee7;
  --home-paper-deep: #e7e5dc;
  --home-mist: #dbe5e4;
  --home-line: rgba(23, 58, 74, 0.19);
  --home-copy: #2f454e;
  --home-display: "Cormorant Garamond", "Noto Sans SC", Georgia, serif;
  background: var(--home-paper);
  color: var(--home-ink-deep);
  overflow-x: hidden;
}

.page-home .home-header {
  background: rgba(240, 238, 231, 0.9);
  border-color: rgba(23, 58, 74, 0.14);
  backdrop-filter: blur(16px) saturate(120%);
}

.page-home .header-inner {
  max-width: 1240px;
  min-height: 72px;
  padding: 0.85rem 2rem;
}

.page-home .site-header--light .logo {
  color: var(--home-ink);
  font-size: 1.65rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.page-home .site-nav {
  gap: 2rem;
  font-size: 0.86rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.page-home .site-nav a {
  position: relative;
  color: rgba(15, 44, 56, 0.65);
}

.page-home .site-nav a::after {
  position: absolute;
  right: 0;
  bottom: -0.45rem;
  left: 0;
  height: 1px;
  content: "";
  background: var(--home-gold);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 180ms ease;
}

.page-home .site-nav a:hover,
.page-home .site-nav a.active {
  color: var(--home-ink);
  text-decoration: none;
}

.page-home .site-nav a:hover::after,
.page-home .site-nav a.active::after {
  transform: scaleX(1);
  transform-origin: left;
}

.page-home .lang-switch {
  border-color: rgba(23, 58, 74, 0.16);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.38);
  padding: 2px;
}

.page-home .lang-btn {
  min-width: 2.75rem;
  border-radius: 999px;
  padding: 0.38rem 0.6rem;
}

.page-home .lang-btn.active {
  background: var(--home-ink);
  color: #f8f5eb;
}

.page-home main.home-main {
  max-width: none;
  margin: 0;
  padding: 0;
}

.section-shell,
.hero-shell {
  width: min(1240px, calc(100% - 4rem));
  margin: 0 auto;
}

.home-kicker {
  margin: 0 0 1.15rem;
  color: var(--home-ocean);
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.17em;
  line-height: 1.4;
  text-transform: uppercase;
}

.home-kicker::before {
  display: inline-block;
  width: 2.25rem;
  height: 1px;
  margin: 0 0.75rem 0.22rem 0;
  content: "";
  background: currentColor;
  opacity: 0.65;
}

.home-kicker--gold {
  color: var(--home-gold-light);
}

.home-hero {
  position: relative;
  display: grid;
  min-height: max(760px, calc(100vh - 72px));
  align-items: center;
  overflow: hidden;
  border-bottom: 1px solid rgba(23, 58, 74, 0.12);
  background:
    radial-gradient(circle at 78% 42%, rgba(255, 255, 255, 0.78) 0, rgba(255, 255, 255, 0) 33%),
    linear-gradient(120deg, #f3f1ea 0%, var(--home-paper) 55%, #e9ece7 100%);
}

.hero-grid {
  position: absolute;
  inset: 0;
  opacity: 0.42;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(23, 58, 74, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 58, 74, 0.055) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: linear-gradient(90deg, transparent 0%, #000 33%, #000 100%);
}

.hero-shell {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 0.88fr) minmax(420px, 1.12fr);
  gap: clamp(2.5rem, 7vw, 7rem);
  align-items: center;
  padding: 5.5rem 0 7rem;
}

.hero-copy {
  position: relative;
  z-index: 2;
  padding-left: clamp(0rem, 3vw, 2rem);
}

.home-title {
  margin: 0 0 1.5rem;
  color: var(--home-ink);
  font-family: var(--home-display);
  font-size: clamp(5rem, 9.5vw, 8.4rem);
  font-weight: 500;
  letter-spacing: -0.045em;
  line-height: 0.78;
}

.home-lead {
  max-width: 35rem;
  margin: 0 0 1.25rem;
  color: var(--home-ink-deep);
  font-family: var(--home-display);
  font-size: clamp(1.75rem, 3vw, 2.55rem);
  font-weight: 500;
  letter-spacing: -0.018em;
  line-height: 1.12;
}

html[lang="zh-CN"] .home-lead,
html[lang="zh-CN"] .home-thesis h2,
html[lang="zh-CN"] .section-heading h2,
html[lang="zh-CN"] .capabilities-heading h2,
html[lang="zh-CN"] .home-cta h2 {
  font-family: "Noto Sans SC", var(--font-sans);
  font-weight: 500;
  letter-spacing: -0.035em;
}

.home-intro {
  max-width: 32rem;
  margin: 0 0 2.25rem;
  color: var(--home-copy);
  font-size: 1rem;
  line-height: 1.85;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1rem;
  align-items: center;
}

.home-button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 0.72rem 1.15rem;
  border: 1px solid transparent;
  color: var(--home-ink);
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.2;
  text-decoration: none;
  transition: background 180ms ease, border-color 180ms ease, color 180ms ease, transform 180ms ease;
}

.home-button:hover {
  text-decoration: none;
  transform: translateY(-2px);
}

.home-button--primary {
  min-width: 176px;
  background: var(--home-ink);
  color: #faf7ed !important;
  box-shadow: 0 12px 30px rgba(15, 44, 56, 0.18);
}

.home-button--primary:hover {
  background: var(--home-ocean);
}

.home-button--text {
  border-bottom-color: rgba(23, 58, 74, 0.28);
  color: var(--home-ink) !important;
}

.hero-note {
  display: flex;
  min-height: 1.5rem;
  align-items: baseline;
  gap: 0.42rem;
  margin-top: 3rem;
  color: rgba(23, 58, 74, 0.58);
  font-family: var(--home-display);
  font-size: 1rem;
  font-style: italic;
}

.note-mark {
  color: var(--home-gold);
  font-family: Georgia, serif;
  font-style: normal;
}

.page-home .phrase-cursor {
  display: inline-block;
  width: 1px;
  height: 1em;
  background: var(--home-gold);
  animation: cursor-blink 1s step-end infinite;
}

.reasoning-scene {
  position: relative;
  width: min(100%, 590px);
  aspect-ratio: 1;
  justify-self: end;
  overflow: hidden;
  background:
    radial-gradient(circle at 86% 15%, rgba(183, 139, 70, 0.1), transparent 27%),
    linear-gradient(90deg, rgba(23, 58, 74, 0.035) 1px, transparent 1px);
  background-size: auto, 25% 100%;
}

.proof-folio__head {
  display: flex;
  min-height: 46px;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid rgba(23, 58, 74, 0.3);
  border-bottom: 1px solid rgba(23, 58, 74, 0.12);
  color: rgba(23, 58, 74, 0.48);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.58rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.proof-folio__head > span:first-child {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
}

.proof-folio__head i {
  color: var(--home-gold);
  font-family: Georgia, serif;
  font-size: 1rem;
  font-style: normal;
}

.proof-folio__theorem {
  position: relative;
  display: grid;
  min-height: 152px;
  align-content: center;
  gap: 0.25rem;
  padding: 0 0 0 12%;
}

.proof-folio__theorem > span,
.proof-ledger__row header,
.proof-ledger__row small,
.proof-folio__foot {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

.proof-folio__theorem > span {
  color: rgba(23, 58, 74, 0.52);
  font-size: 0.6rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.proof-folio__theorem strong {
  position: relative;
  z-index: 1;
  color: var(--home-ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(3.7rem, 8vw, 5.4rem);
  font-weight: 400;
  letter-spacing: -0.06em;
  line-height: 1.08;
  white-space: nowrap;
}

.proof-folio__theorem strong i {
  margin: 0 0.16em;
  color: var(--home-gold);
  font-family: var(--home-display);
  font-size: 0.72em;
  font-style: italic;
  font-weight: 500;
  vertical-align: 0.08em;
}

.proof-ledger {
  position: relative;
  border-top: 1px solid rgba(23, 58, 74, 0.16);
}

.proof-ledger::before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 5.3rem;
  width: 1px;
  content: "";
  background: linear-gradient(var(--home-gold), rgba(40, 93, 112, 0.3) 72%, #b14538);
}

.proof-ledger__row {
  position: relative;
  display: grid;
  min-height: 76px;
  grid-template-columns: 5.3rem minmax(0, 1fr);
  border-bottom: 1px solid rgba(23, 58, 74, 0.11);
  opacity: 0;
  animation: proof-set 560ms ease-out forwards;
}

.proof-ledger__row::before {
  position: absolute;
  top: 50%;
  left: 5.3rem;
  width: 0.65rem;
  height: 1px;
  content: "";
  background: var(--home-ocean);
}

.proof-ledger__row--b { animation-delay: 90ms; }
.proof-ledger__row--c { animation-delay: 180ms; }
.proof-ledger__row--d { animation-delay: 270ms; }

@keyframes proof-set {
  from { opacity: 0; transform: translateY(5px); }
  to { opacity: 1; transform: translateY(0); }
}

.proof-ledger__row header {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  padding-right: 1rem;
  color: rgba(23, 58, 74, 0.48);
  font-size: 0.58rem;
  letter-spacing: 0.05em;
}

.proof-ledger__row header b {
  color: var(--home-ocean);
  font-size: 0.67rem;
}

.proof-ledger__row > div {
  display: flex;
  min-width: 0;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 0.2rem 0.6rem 1.35rem;
}

.proof-ledger__row p {
  margin: 0;
  color: var(--home-ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(1.25rem, 3.15vw, 1.72rem);
  line-height: 1.12;
  white-space: nowrap;
}

.proof-ledger__row small {
  flex: 0 0 auto;
  color: rgba(23, 58, 74, 0.52);
  font-size: 0.57rem;
  letter-spacing: 0.035em;
  white-space: nowrap;
}

.proof-ledger__row--d {
  background: linear-gradient(90deg, transparent 36%, rgba(177, 69, 56, 0.06));
}

.proof-ledger__row--d::before {
  background: #b14538;
}

.proof-ledger__row--d header,
.proof-ledger__row--d header b {
  color: #a94639;
}

.proof-ledger__row--d > div strong {
  color: #b14538;
  font-family: Georgia, serif;
  font-size: 1.35rem;
  font-weight: 400;
}

.proof-folio__foot {
  display: flex;
  min-height: 44px;
  align-items: center;
  justify-content: space-between;
  color: rgba(23, 58, 74, 0.45);
  font-size: 0.54rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.proof-folio__foot > span:last-child {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  color: var(--home-ocean);
}

.proof-folio__foot i {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--home-gold);
  box-shadow: 0 0 0 4px rgba(183, 139, 70, 0.11);
}

.hero-scroll {
  position: absolute;
  bottom: 1.8rem;
  left: 50%;
  z-index: 2;
  color: rgba(23, 58, 74, 0.58) !important;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-decoration: none;
  text-transform: uppercase;
  transform: translateX(-50%);
}

.hero-scroll::after {
  display: block;
  width: 1px;
  height: 2.3rem;
  margin: 0.6rem auto -2.4rem;
  content: "";
  background: linear-gradient(var(--home-gold), transparent);
}

.home-thesis {
  position: relative;
  overflow: hidden;
  background: var(--home-ink-deep);
  color: #edf0ea;
}

.home-thesis::before {
  position: absolute;
  top: -260px;
  right: -150px;
  width: 570px;
  height: 570px;
  border: 1px solid rgba(216, 186, 123, 0.16);
  border-radius: 50%;
  content: "";
}

.thesis-layout {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(340px, 0.72fr);
  gap: clamp(3rem, 9vw, 9rem);
  align-items: end;
  padding: 7.5rem 0;
}

.home-thesis h2,
.section-heading h2,
.capabilities-heading h2,
.home-cta h2 {
  margin: 0;
  font-family: var(--home-display);
  font-size: clamp(2.8rem, 5.4vw, 5.2rem);
  font-weight: 500;
  letter-spacing: -0.035em;
  line-height: 0.98;
}

.thesis-copy > p {
  margin: 0 0 2.5rem;
  color: rgba(237, 240, 234, 0.74);
  font-size: 1.02rem;
  line-height: 1.9;
}

.reasoning-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  align-items: center;
  color: var(--home-gold-light);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.63rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.reasoning-legend i {
  width: 1.7rem;
  height: 1px;
  background: rgba(216, 186, 123, 0.38);
}

.home-method {
  position: relative;
  padding: 8rem 0 8.5rem;
  background: var(--home-mist);
}

.home-method::after {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 1px;
  content: "";
  background: linear-gradient(90deg, transparent, rgba(23, 58, 74, 0.28), transparent);
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.58fr);
  gap: clamp(3rem, 9vw, 9rem);
  align-items: end;
  margin-bottom: 5.5rem;
}

.section-heading h2 {
  max-width: 12ch;
  color: var(--home-ink);
}

.section-heading > p {
  margin: 0;
  padding-bottom: 0.5rem;
  color: var(--home-copy);
  line-height: 1.85;
}

.method-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--home-line);
  list-style: none;
}

.method-item {
  position: relative;
  min-height: 345px;
  padding: 1.25rem 1.7rem 2rem;
  border-right: 1px solid var(--home-line);
}

.method-item:first-child {
  border-left: 1px solid var(--home-line);
}

.method-item::before {
  position: absolute;
  top: -1px;
  right: 100%;
  left: 0;
  height: 2px;
  content: "";
  background: var(--home-gold);
  transition: right 260ms ease;
}

.method-item:hover::before {
  right: 0;
}

.method-number {
  display: block;
  color: rgba(23, 58, 74, 0.48);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.66rem;
  letter-spacing: 0.09em;
}

.method-symbol {
  display: grid;
  width: 4.25rem;
  height: 4.25rem;
  margin: 2.8rem 0 3.25rem;
  place-items: center;
  border: 1px solid rgba(23, 58, 74, 0.22);
  border-radius: 50%;
  color: var(--home-ocean);
  font-family: var(--home-display);
  font-size: 1.6rem;
}

.method-item h3 {
  margin: 0 0 0.85rem;
  color: var(--home-ink);
  font-family: var(--home-display);
  font-size: 1.45rem;
  font-weight: 600;
  line-height: 1.15;
}

html[lang="zh-CN"] .method-item h3,
html[lang="zh-CN"] .capability-row h3 {
  font-family: "Noto Sans SC", var(--font-sans);
  font-weight: 500;
}

.method-item p {
  margin: 0;
  color: rgba(47, 69, 78, 0.82);
  font-size: 0.88rem;
  line-height: 1.8;
}

.home-capabilities {
  padding: 8rem 0 9rem;
  background:
    linear-gradient(90deg, rgba(23, 58, 74, 0.035) 1px, transparent 1px),
    var(--home-paper-deep);
  background-size: 25% 100%;
}

.capabilities-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.72fr) minmax(480px, 1.28fr);
  gap: clamp(4rem, 11vw, 11rem);
  align-items: start;
}

.capabilities-heading {
  position: sticky;
  top: 120px;
}

.capabilities-heading h2 {
  max-width: 8ch;
  color: var(--home-ink);
}

.capabilities-heading > p:last-child {
  max-width: 25rem;
  margin: 2rem 0 0;
  color: var(--home-copy);
  line-height: 1.8;
}

.capability-list {
  border-top: 1px solid var(--home-line);
}

.capability-row {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 2rem;
  padding: 2.7rem 0 3rem;
  border-bottom: 1px solid var(--home-line);
}

.capability-mark {
  padding-top: 0.35rem;
  color: var(--home-gold);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.09em;
}

.capability-row h3 {
  margin: 0 0 0.9rem;
  color: var(--home-ink);
  font-family: var(--home-display);
  font-size: clamp(1.6rem, 2.5vw, 2.15rem);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.1;
}

.capability-row p {
  max-width: 42rem;
  margin: 0;
  color: var(--home-copy);
  line-height: 1.85;
}

.home-cta {
  position: relative;
  overflow: hidden;
  padding: 6.5rem 0;
  background: var(--home-ink);
  color: #f4f3ec;
}

.cta-orbit {
  position: absolute;
  top: 50%;
  right: -6rem;
  width: 32rem;
  height: 32rem;
  border: 1px solid rgba(216, 186, 123, 0.17);
  border-radius: 50%;
  transform: translateY(-50%);
}

.cta-orbit::after {
  position: absolute;
  inset: 4rem;
  border: 1px dashed rgba(216, 186, 123, 0.13);
  border-radius: inherit;
  content: "";
}

.cta-layout {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 4rem;
  align-items: end;
}

.home-cta h2 {
  max-width: 13ch;
}

.home-button--light {
  min-width: 190px;
  border-color: rgba(255, 255, 255, 0.35);
  background: #f3f0e6;
  color: var(--home-ink) !important;
}

.home-button--light:hover {
  border-color: var(--home-gold-light);
  background: var(--home-gold-light);
}

.page-home .home-footer {
  border: 0;
  background: var(--home-ink-deep);
  color: rgba(237, 240, 234, 0.62);
  text-align: left;
}

.footer-inner {
  display: grid;
  width: min(1240px, calc(100% - 4rem));
  min-height: 112px;
  margin: 0 auto;
  grid-template-columns: auto 1fr auto;
  gap: 2rem;
  align-items: center;
}

.footer-brand {
  color: #f2efe7 !important;
  font-family: var(--home-display);
  font-size: 1.45rem;
}

.footer-inner > p {
  margin: 0;
}

.footer-inner > p:nth-child(2) {
  font-size: 0.78rem;
  text-align: center;
}

.page-home .footer-links {
  gap: 1.5rem;
}

.page-home .footer-links a {
  color: rgba(237, 240, 234, 0.72);
  font-size: 0.78rem;
}

.page-home .footer-links a:hover {
  color: var(--home-gold-light);
}

.page-home :focus-visible {
  outline: 2px solid var(--home-gold);
  outline-offset: 4px;
}

@media (max-width: 980px) {
  .hero-shell {
    grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1.1fr);
    gap: 2rem;
  }

  .home-title {
    font-size: clamp(4.7rem, 10vw, 6.8rem);
  }

  .reasoning-scene {
    width: min(100%, 540px);
  }

  .method-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .method-item:nth-child(3) {
    border-left: 1px solid var(--home-line);
  }

  .method-item:nth-child(n + 3) {
    border-top: 1px solid var(--home-line);
  }

  .capabilities-layout {
    gap: 4rem;
  }
}

@media (max-width: 760px) {
  .page-home .header-inner {
    min-height: 64px;
    padding: 0.72rem 1.25rem;
  }

  .section-shell,
  .hero-shell,
  .footer-inner {
    width: min(100% - 2.5rem, 620px);
  }

  .home-hero {
    min-height: auto;
  }

  .hero-grid {
    mask-image: linear-gradient(#000, transparent);
  }

  .hero-shell {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 5rem 0 5.5rem;
  }

  .hero-copy {
    padding: 0;
  }

  .home-title {
    font-size: clamp(4.6rem, 22vw, 6.6rem);
  }

  .home-lead {
    font-size: clamp(1.75rem, 8vw, 2.35rem);
  }

  .hero-note {
    margin-top: 2rem;
  }

  .reasoning-scene {
    width: min(100%, 520px);
    justify-self: center;
  }

  .hero-scroll {
    display: none;
  }

  .thesis-layout,
  .section-heading,
  .capabilities-layout,
  .cta-layout {
    grid-template-columns: 1fr;
  }

  .thesis-layout {
    gap: 2.5rem;
    padding: 5.5rem 0;
  }

  .home-thesis h2,
  .section-heading h2,
  .capabilities-heading h2,
  .home-cta h2 {
    font-size: clamp(2.8rem, 13vw, 4.25rem);
  }

  .home-method,
  .home-capabilities {
    padding: 5.5rem 0;
  }

  .section-heading {
    gap: 2rem;
    margin-bottom: 3.5rem;
  }

  .capabilities-heading {
    position: static;
  }

  .home-capabilities {
    background-size: 50% 100%;
  }

  .cta-layout {
    gap: 2.5rem;
    align-items: start;
  }

  .home-button--light {
    justify-self: start;
  }

  .footer-inner {
    min-height: auto;
    padding: 2rem 0;
    grid-template-columns: 1fr auto;
  }

  .footer-inner > p:nth-child(2) {
    display: none;
  }
}

@media (max-width: 520px) {
  .page-home .header-inner {
    flex-direction: row;
    align-items: center;
  }

  .page-home .header-left {
    width: auto;
  }

  .page-home .site-header--light .logo {
    font-size: 1.35rem;
  }

  .page-home .site-nav {
    gap: 0.9rem;
    font-size: 0.69rem;
  }

  .page-home .lang-switch {
    display: none;
  }

  .home-kicker {
    font-size: 0.65rem;
  }

  .home-intro {
    font-size: 0.93rem;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .home-button {
    width: 100%;
  }

  .reasoning-scene {
    margin: 0 -1rem;
    width: calc(100% + 2rem);
    min-height: 522px;
    aspect-ratio: auto;
  }

  .proof-folio__head {
    font-size: 0.5rem;
  }

  .proof-folio__theorem {
    min-height: 138px;
    padding-left: 8%;
  }

  .proof-folio__theorem strong {
    font-size: clamp(3.25rem, 16vw, 4.2rem);
  }

  .proof-ledger::before,
  .proof-ledger__row::before {
    left: 5.3rem;
  }

  .proof-ledger__row {
    min-height: 72px;
    grid-template-columns: 5.3rem minmax(0, 1fr);
  }

  .proof-ledger__row header {
    gap: 0.3rem;
    padding-right: 0.45rem;
    font-size: 0.51rem;
  }

  .proof-ledger__row > div {
    padding-left: 0.9rem;
  }

  .proof-ledger__row p {
    font-size: clamp(1.04rem, 5.2vw, 1.35rem);
  }

  .reasoning-legend {
    align-items: flex-start;
    flex-direction: column;
  }

  .reasoning-legend i {
    width: 1px;
    height: 0.7rem;
    margin-left: 0.2rem;
  }

  .method-list {
    grid-template-columns: 1fr;
  }

  .method-item,
  .method-item:nth-child(3) {
    min-height: 0;
    border-top: 1px solid var(--home-line);
    border-right: 1px solid var(--home-line);
    border-left: 1px solid var(--home-line);
  }

  .method-item:first-child {
    border-top: 0;
  }

  .method-symbol {
    margin: 2rem 0 2.25rem;
  }

  .capability-row {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .capability-mark {
    padding: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-home *,
  .page-home *::before,
  .page-home *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}