:root {
  --ink: #101623;
  --muted: #5d6676;
  --soft: #f4f6f8;
  --surface: #ffffff;
  --line: #d7dde6;
  --blue: #00629b;
  --red: #b01e2e;
  --teal: #08747f;
  --amber: #d98c1f;
  --dark: #081120;
  --shadow: 0 18px 50px rgba(16, 22, 35, 0.11);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: #fbfcfe;
  font-family: Inter, "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  color: #ffffff;
  background: linear-gradient(180deg, rgba(2, 11, 24, 0.68), rgba(2, 11, 24, 0.08));
  border-bottom: 1px solid rgba(109, 225, 255, 0.1);
  backdrop-filter: blur(16px);
  transition: background 0.24s ease, border-color 0.24s ease, color 0.24s ease;
}

.site-header.is-scrolled {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.95);
  border-bottom-color: var(--line);
  box-shadow: 0 10px 30px rgba(16, 22, 35, 0.08);
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px clamp(20px, 4vw, 64px);
}

.nav-left {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  color: #ffffff;
  background: rgba(43, 226, 221, 0.18);
  border: 1px solid rgba(105, 232, 255, 0.65);
  border-radius: 6px;
  box-shadow: 0 0 18px rgba(43, 226, 221, 0.28), inset 0 0 14px rgba(105, 232, 255, 0.22);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 19px;
}

.site-header.is-scrolled .brand-mark {
  background: var(--blue);
  border-color: var(--blue);
  box-shadow: none;
}

.language-toggle {
  padding: 5px 12px;
  color: rgba(255, 255, 255, 0.9);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 5px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
  white-space: nowrap;
}

.language-toggle:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.45);
}

.site-header.is-scrolled .language-toggle {
  color: #333d4f;
  background: rgba(0, 0, 0, 0.06);
  border-color: rgba(0, 0, 0, 0.15);
}

.site-header.is-scrolled .language-toggle:hover {
  background: rgba(0, 0, 0, 0.1);
  border-color: rgba(0, 0, 0, 0.3);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 22px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 16px;
  font-weight: 800;
}

.site-header.is-scrolled .nav-links {
  color: #333d4f;
}

.nav-links a:hover,
.footer-links a:hover {
  color: #69e8ff;
}

.site-header.is-scrolled .nav-links a:hover {
  color: var(--blue);
}

.hero {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 100svh;
  overflow: hidden;
  color: #ffffff;
  background:
    radial-gradient(circle at 68% 28%, rgba(44, 214, 255, 0.18), transparent 24%),
    radial-gradient(circle at 28% 72%, rgba(28, 198, 181, 0.12), transparent 28%),
    linear-gradient(180deg, #041428 0%, #061629 45%, #03101f 100%);
  isolation: isolate;
}

.hero-canvas,
.hero-atmosphere,
.hero-overlay {
  position: absolute;
  inset: 0;
}

.hero-canvas {
  z-index: -3;
  width: 100%;
  height: 100%;
}

.hero-atmosphere {
  z-index: -2;
  background:
    linear-gradient(90deg, transparent 0%, rgba(72, 216, 255, 0.09) 48%, transparent 100%),
    repeating-linear-gradient(90deg, rgba(117, 225, 255, 0.04) 0 1px, transparent 1px 92px);
  mask-image: linear-gradient(180deg, transparent 0%, #000 12%, #000 88%, transparent 100%);
  opacity: 0.72;
  animation: drift-field 18s linear infinite;
}

.hero-overlay {
  z-index: -1;
  background:
    radial-gradient(ellipse at center, rgba(4, 20, 40, 0.06) 0%, rgba(2, 8, 18, 0.68) 78%),
    linear-gradient(180deg, rgba(2, 10, 22, 0.1), rgba(2, 10, 22, 0.28) 64%, rgba(2, 10, 22, 0.86));
}

.hero-content {
  width: 100%;
  max-width: 1080px;
  padding: clamp(120px, 12vw, 170px) clamp(20px, 6vw, 96px) 82px;
  text-align: center;
}

.hero h1 {
  margin: 0;
  font-family: Inter, "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  font-size: clamp(74px, 10vw, 150px);
  font-weight: 900;
  line-height: 0.9;
  letter-spacing: 0;
  text-shadow: 0 0 22px rgba(139, 238, 255, 0.28), 0 12px 38px rgba(0, 0, 0, 0.42);
}

.hero-subtitle {
  width: 100%;
  max-width: 820px;
  margin: 22px auto 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(23px, 3vw, 44px);
  line-height: 1.12;
  overflow-wrap: break-word;
  color: #e8edf5;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 6px;
  font-weight: 800;
  font-size: 14px;
}

.button.primary {
  color: #ffffff;
  background: var(--red);
}

.button.secondary {
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.5);
}

@keyframes drift-field {
  from {
    transform: translateX(-2%);
  }

  to {
    transform: translateX(2%);
  }
}

[id] {
  scroll-margin-top: 98px;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(240px, 330px) minmax(0, 1fr);
  gap: clamp(28px, 5vw, 80px);
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding: clamp(56px, 7vw, 98px) 0;
}

.paper-meta {
  align-self: start;
  position: sticky;
  top: 104px;
  padding: 26px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-top: 4px solid var(--blue);
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(16, 22, 35, 0.06);
}

.paper-meta h2 {
  margin: 0 0 24px;
  font-size: 22px;
  line-height: 1.2;
}

.paper-meta dl {
  margin: 0;
}

.paper-meta dt {
  color: #222b3d;
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

.paper-meta dd {
  margin: 4px 0 18px;
  color: var(--muted);
  font-size: 14px;
}

.paper-meta a {
  color: var(--blue);
  overflow-wrap: anywhere;
}

.eyebrow,
.section-kicker,
.meta-label {
  margin: 0 0 12px;
  color: var(--red);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.article-main h2,
.section-head h2,
.split-copy h2 {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(34px, 4.6vw, 56px);
  line-height: 1.05;
  letter-spacing: 0;
}

.lead {
  margin-top: 24px;
  color: #273247;
  font-size: clamp(18px, 2vw, 22px);
  line-height: 1.55;
}

.article-main p:not(.section-kicker):not(.lead),
.section-head p:not(.section-kicker),
.split-copy p,
.module-grid p,
.comparison-item p,
.usecase-grid p {
  color: var(--muted);
}

.highlight-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 34px;
}

.highlight-grid div,
.module-grid section,
.comparison-item,
.usecase-grid div {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

.highlight-grid div {
  padding: 22px;
}

h3 {
  margin: 0 0 10px;
  font-size: 20px;
  line-height: 1.25;
}

.highlight-grid p,
.module-grid p,
.comparison-item p,
.usecase-grid p {
  margin: 0;
}

.band,
.content-section,
.usecase-band {
  padding: clamp(56px, 7vw, 96px) clamp(20px, 5vw, 72px);
}

.split-section {
  padding: clamp(56px, 7vw, 96px) 0;
}

.band {
  background: var(--soft);
  border-block: 1px solid var(--line);
}

.content-section {
  background: #fbfcfe;
}

.section-head {
  width: min(1180px, 100%);
  margin: 0 auto 34px;
}

.section-head p:not(.section-kicker) {
  max-width: 820px;
  margin: 18px 0 0;
  font-size: 17px;
}

.comparison {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.comparison-item {
  padding: 24px;
  min-height: 230px;
}

.comparison-item.strong {
  border-top: 4px solid var(--red);
}

.item-index {
  display: block;
  color: var(--amber);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 42px;
  line-height: 1;
  margin-bottom: 24px;
}

.paper-figure {
  width: min(1180px, 100%);
  margin: 0 auto;
  padding: 18px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.paper-figure img {
  width: 100%;
  border: 1px solid #edf0f4;
  border-radius: 6px;
}

figcaption {
  margin-top: 10px;
  color: var(--muted);
  font-size: 13px;
}

.module-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  width: min(1180px, 100%);
  margin: 24px auto 0;
}

.module-grid section {
  padding: 22px;
  border-top: 4px solid var(--blue);
}

.module-grid section:nth-child(2) {
  border-top-color: var(--amber);
}

.module-grid section:nth-child(3) {
  border-top-color: var(--teal);
}

.module-grid section:nth-child(4) {
  border-top-color: var(--red);
}

.split-section {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(0, 1.2fr);
  gap: clamp(28px, 5vw, 72px);
  align-items: center;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.clean-list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  color: #3e485b;
}

.clean-list li {
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

.scene-gallery {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.scene-gallery figure,
.data-gallery figure,
.ckm-grid figure {
  margin: 0;
  overflow: hidden;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.scene-gallery img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.scene-gallery figure:nth-child(2) img {
  object-position: center 58%;
}

.scene-gallery figcaption,
.data-gallery figcaption,
.ckm-grid figcaption {
  padding: 10px 12px 12px;
}

.data-gallery {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 12px;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.data-gallery img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.data-gallery figure:nth-child(5) img {
  object-position: center 20%;
}

.ckm-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.ckm-grid img {
  width: 100%;
  aspect-ratio: 1 / 0.9;
  object-fit: cover;
  object-position: center 52%;
}

.usecase-band {
  color: #ffffff;
  background: var(--dark);
}

.usecase-band .section-kicker {
  color: #f3c25c;
}

.usecase-band .section-head h2 {
  color: #ffffff;
}

.usecase-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.usecase-grid div {
  padding: 22px;
  color: #ffffff;
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.16);
}

.usecase-grid p {
  color: #cbd4e1;
}

/* ── Developers Section ── */
.developers-section {
  background: #fbfcfe;
}

.dev-block {
  width: min(1180px, 100%);
  margin: 0 auto 48px;
}

.dev-block h3 {
  margin: 0 0 22px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(24px, 3vw, 32px);
  color: var(--ink);
}

.dev-org-grid {
  display: grid;
  gap: 16px;
}

.dev-org-card {
  padding: 24px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-left: 4px solid var(--blue);
  border-radius: 8px;
}

.dev-org-name {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 800;
  color: var(--ink);
}

.dev-org-affil {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.dev-core-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}

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

.dev-card {
  padding: 22px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-top: 4px solid var(--red);
  border-radius: 8px;
}

.dev-name {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 800;
  color: var(--ink);
}

.dev-role {
  margin: 0 0 4px;
  font-size: 13px;
  font-weight: 700;
  color: var(--red);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.dev-affil {
  margin: 6px 0 0;
  font-size: 13px;
  color: var(--muted);
}

.site-footer {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 12px;
  padding: 34px clamp(20px, 5vw, 72px);
  color: #cbd4e1;
  background: #050a13;
}

.footer-version {
  margin: 0;
  font-size: 13px;
  color: #64748b;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 16px;
  color: #ffffff;
  font-weight: 700;
}

/* ── Modal ── */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.24s ease;
}

.modal-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}

.modal-box {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 24px 36px;
  background: #ffffff;
  border-radius: 8px;
  box-shadow: 0 18px 50px rgba(16, 22, 35, 0.18);
  font-size: 20px;
  font-weight: 800;
  color: var(--ink);
}

.modal-close {
  padding: 4px 10px;
  background: none;
  border: 1px solid var(--line);
  border-radius: 4px;
  font-size: 20px;
  cursor: pointer;
  color: var(--muted);
  line-height: 1;
}

.modal-close:hover {
  color: var(--ink);
  border-color: var(--muted);
}

@media (max-width: 1020px) {
  .highlight-grid,
  .comparison,
  .module-grid,
  .data-gallery,
  .ckm-grid,
  .usecase-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .article-layout,
  .split-section {
    grid-template-columns: 1fr;
  }

  .paper-meta {
    position: static;
  }

  .dev-core-grid,
  .dev-grid-three {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 720px) {
  .main-nav {
    align-items: flex-start;
    gap: 12px;
    flex-direction: column;
  }

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

  .nav-links {
    width: 100%;
    justify-content: flex-start;
    gap: 12px 16px;
    font-size: 14px;
  }

  .hero {
    height: 900px;
    min-height: 900px;
  }

  .hero-content {
    padding-top: 72px;
    padding-bottom: 96px;
  }

  .hero h1 {
    font-size: clamp(62px, 19vw, 78px);
  }

  .hero-subtitle {
    max-width: 334px;
    font-size: clamp(18px, 4.8vw, 22px);
    line-height: 1.2;
  }

  .highlight-grid,
  .comparison,
  .module-grid,
  .data-gallery,
  .ckm-grid,
  .usecase-grid,
  .site-footer,
  .dev-core-grid,
  .dev-grid-three {
    grid-template-columns: 1fr;
  }

  .scene-gallery img {
    height: 220px;
  }

  .paper-figure {
    padding: 10px;
  }

  .footer-links {
    justify-content: flex-start;
  }

  .dev-block {
    margin-bottom: 32px;
  }
}