:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --ink: #14253d;
  --muted: #64748b;
  --line: #d4eaf4;
  --accent: #0783c0;
  --accent-strong: #006f9f;
  --accent-dark: #075a82;
  --accent-soft: #ecf8fc;
  --mint: #ecf8fc;
  --mint-dark: #3b7592;
  --display: "Bricolage Grotesque", "Trebuchet MS", sans-serif;
  --body: "IBM Plex Sans", "Trebuchet MS", sans-serif;
  --max: 1180px;
  --pad: clamp(1.25rem, 4vw, 3.5rem);
  --section-space: clamp(3.75rem, 6vw, 5.5rem);
  --text-min: .875rem;
  --text-body: .9375rem;
  --text-lede: 1rem;
  --text-subtitle: 1.125rem;
  --text-card-title: 1.25rem;
  --text-section-title: 1.375rem;
  --text-max: 1.5rem;
}

html[lang="zh-CN"] {
  --display: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --body: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--body);
  line-height: 1.55;
  text-rendering: optimizeLegibility;
}
img, video { max-width: 100%; }
a { color: inherit; }
button { font: inherit; }

.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 1000; padding: .7rem 1rem; background: var(--ink); color: white; }
.skip-link:focus { top: 1rem; }

.site-header {
  width: min(calc(100% - (2 * var(--pad))), var(--max));
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  margin: 0 auto;
  border-bottom: 1px solid var(--line);
}
.brand { display: inline-flex; align-items: center; gap: .65rem; font-family: var(--display); font-weight: 600; text-decoration: none; }
.brand img { border-radius: 10px; }
.site-header nav { display: flex; align-items: center; gap: 1.7rem; }
.site-header nav a { color: var(--muted); font-size: var(--text-min); font-weight: 500; text-decoration: none; }
.site-header nav a:hover { color: var(--ink); }
.site-header .report-link { padding: .62rem .9rem; color: var(--ink); border: 1px solid var(--line); border-radius: 999px; background: var(--surface); }
.language-switch { display: inline-flex; align-items: center; gap: 2px; padding: 2px; border: 1px solid var(--line); border-radius: 999px; background: var(--surface); }
.language-switch a { min-width: 32px; padding: .28rem .48rem; border-radius: 999px; text-align: center; line-height: 1.2; }
.language-switch a[aria-current="page"] { color: #fff; background: var(--accent); }
.language-switch a:hover { color: var(--accent-dark); text-decoration: none; background: var(--accent-soft); }
.language-switch a[aria-current="page"]:hover { color: #fff; background: var(--accent-strong); }

.hero, .summary, .section, .evidence, .closing, .site-footer {
  width: min(calc(100% - (2 * var(--pad))), var(--max));
  margin-left: auto;
  margin-right: auto;
}
.hero { display: grid; grid-template-columns: .82fr 1.18fr; gap: clamp(2rem, 4vw, 4rem); align-items: center; padding-top: clamp(3rem, 5vw, 4.5rem); padding-bottom: clamp(3rem, 5vw, 4.5rem); }
.eyebrow { margin: 0 0 .9rem; color: var(--mint-dark); font-size: var(--text-min); font-weight: 600; letter-spacing: .1em; text-transform: uppercase; }
.hero-copy .eyebrow { font-size: var(--text-lede); letter-spacing: .06em; }
h1, h2, h3 { font-family: var(--display); }
.hero h1 { max-width: 540px; margin: 0; font-size: var(--text-max); font-weight: 600; letter-spacing: -.025em; line-height: 1.15; }
.lede { max-width: 590px; margin: 1.5rem 0 0; color: var(--muted); font-size: var(--text-lede); line-height: 1.7; }
.lede strong { color: var(--ink); font-weight: 600; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .7rem; margin-top: 1.4rem; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: .75rem 1.15rem; border: 1px solid transparent; border-radius: 999px; font-size: var(--text-min); font-weight: 600; text-decoration: none; transition: transform .2s ease, background .2s ease; }
.button:hover { transform: translateY(-2px); }
.button.primary { color: white; background: var(--accent); }
.button.primary:hover { background: var(--accent-strong); }
.button.secondary { border-color: var(--line); background: var(--surface); }
.capability-list { display: flex; flex-wrap: wrap; gap: .55rem; margin: 1.25rem 0 0; padding: 0; list-style: none; }
.capability-list li { padding: .38rem .68rem; color: var(--mint-dark); background: var(--mint); border-radius: 999px; font-size: var(--text-min); }
.hero-media { margin: 0; }
.hero-media video { display: block; width: 100%; aspect-ratio: 2120 / 1080; object-fit: contain; background: var(--accent-soft); border: 1px solid var(--line); border-radius: 12px; box-shadow: 0 20px 50px rgba(0, 111, 159, .1); }
.hero-media figcaption { margin-top: .7rem; color: var(--muted); font-size: var(--text-min); }

.summary { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.summary div { padding: 1.5rem 1.8rem; border-right: 1px solid var(--line); }
.summary div:first-child { padding-left: 0; }
.summary div:last-child { padding-right: 0; border-right: 0; }
.summary span { color: var(--accent); font-size: var(--text-min); font-weight: 600; letter-spacing: .1em; text-transform: uppercase; }
.summary p { margin: .45rem 0 0; font-size: var(--text-body); }

.section { padding-top: var(--section-space); padding-bottom: var(--section-space); border-bottom: 1px solid var(--line); }
.section-header { display: grid; grid-template-columns: .9fr 1.1fr; gap: 1.5rem; align-items: end; margin-bottom: 2.25rem; }
.section-header .eyebrow { grid-column: 1 / -1; margin-bottom: -.5rem; }
.section-header h2, .closing h2 { margin: 0; font-size: var(--text-section-title); font-weight: 600; letter-spacing: -.02em; line-height: 1.18; }
.section-header > p:last-child { max-width: 510px; margin: 0; color: var(--muted); }

.demo-grid { display: grid; grid-template-columns: 1fr; gap: 1.25rem; }
.demo-card { display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(250px, .55fr); align-items: stretch; min-width: 0; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); overflow: hidden; }
.demo-videos { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; align-self: stretch; background: var(--line); border-right: 1px solid var(--line); }
.demo-videos.is-single { grid-template-columns: 1fr; }
.demo-video { margin: 0; background: var(--surface); }
.demo-video video { display: block; width: 100%; height: auto; aspect-ratio: 2120 / 1080; object-fit: contain; background: var(--accent-soft); }
.demo-video figcaption { padding: .5rem .7rem; color: var(--muted); border-top: 1px solid var(--line); font-size: var(--text-min); }
.demo-info { align-self: center; padding: 1.15rem; }
.demo-info > span { color: var(--accent); font-size: var(--text-min); font-weight: 600; letter-spacing: .1em; text-transform: uppercase; }
.demo-info h3 { margin: .55rem 0 .7rem; font-size: var(--text-card-title); font-weight: 600; letter-spacing: -.015em; line-height: 1.22; }
.demo-info p { margin: 0; color: var(--muted); font-size: var(--text-body); line-height: 1.7; }
.result-points { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.75rem; margin-top: 2.75rem; }
.result-points div { padding-top: 1.2rem; border-top: 3px solid var(--accent-soft); }
.result-points strong { font-family: var(--display); font-size: var(--text-subtitle); }
.result-points p { margin: .4rem 0 0; color: var(--muted); font-size: var(--text-min); }

.section-header.compact { display: block; max-width: 760px; }
.section-header.compact .eyebrow { margin-bottom: .9rem; }
.paper-figure { margin: 1.75rem 0 0; padding: clamp(.75rem, 2vw, 1.4rem); border: 1px solid var(--line); border-radius: 14px; background: var(--surface); }
.paper-figure img { display: block; width: 100%; height: auto; background: #fff; }
.figure-image-link { position: relative; display: block; border-radius: 8px; text-decoration: none; overflow: hidden; }
.figure-image-link > span { position: absolute; top: .65rem; right: .65rem; display: grid; width: 30px; height: 30px; place-items: center; color: #fff; background: rgba(0, 111, 159, .88); border-radius: 50%; font-size: var(--text-min); box-shadow: 0 4px 12px rgba(0, 111, 159, .2); }
.figure-image-link:hover > span { background: var(--accent-dark); transform: translateY(-1px); }
.paper-figure figcaption { display: grid; grid-template-columns: .28fr 1fr; gap: 2rem; padding: 1.25rem .45rem .2rem; border-top: 1px solid var(--line); }
.paper-figure figcaption > span { color: var(--accent); font-size: var(--text-min); font-weight: 600; letter-spacing: .09em; text-transform: uppercase; }
.paper-figure figcaption h3 { margin: 0; font-size: var(--text-card-title); font-weight: 600; letter-spacing: -.015em; line-height: 1.24; }
.paper-figure figcaption p { max-width: 760px; margin: .65rem 0 0; color: var(--muted); font-size: var(--text-min); line-height: 1.65; }
.pipeline-figure img { border-radius: 8px 8px 0 0; }
.overview-figure picture { display: block; }
.overview-figure img { border: 1px solid var(--line); border-radius: 8px; }
.analysis-figure { display: grid; grid-template-columns: .35fr .65fr; gap: 1.75rem; align-items: center; margin-top: 3rem; background: #f8fcfe; }
.analysis-figure figcaption { display: block; padding: .5rem; border-top: 0; }
.analysis-figure figcaption > span { display: block; margin-bottom: .9rem; }
.analysis-figure img { border: 1px solid var(--line); border-radius: 8px; }

.method-notes { display: grid; grid-template-columns: 1fr; gap: 3rem; margin-top: 3.5rem; }
.method-notes article { min-width: 0; }
.method-notes article + article { padding-top: 3rem; border-top: 1px solid var(--line); }
.method-notes h3 { max-width: 520px; margin: 0 0 1rem; font-size: var(--text-section-title); font-weight: 600; letter-spacing: -.02em; line-height: 1.2; }
.method-notes article > p:last-of-type { max-width: 520px; margin: 0; color: var(--muted); }
.va-visual { width: min(100%, 940px); margin: 1.5rem auto 0; border: 1px solid var(--line); background: var(--surface); }
.va-visual picture, .va-visual img { display: block; width: 100%; height: auto; }
.training-steps { display: grid; grid-template-columns: repeat(2, 1fr); gap: .7rem; margin: 1.5rem 0 0; padding: 0; list-style: none; counter-reset: stage; }
.training-steps li { padding: 1rem; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; }
.training-steps span, .training-steps strong { display: block; }.training-steps span { margin-bottom: .5rem; color: var(--accent); font-size: var(--text-min); text-transform: uppercase; }.training-steps strong { font-family: var(--display); }

.evidence { display: flex; justify-content: space-between; gap: 3rem; padding-top: 2rem; padding-bottom: 2rem; border-bottom: 1px solid var(--line); }
.evidence p { max-width: 700px; margin: 0; color: var(--muted); font-size: var(--text-min); }
.evidence a { flex: 0 0 auto; font-size: var(--text-min); font-weight: 600; }
.closing { display: flex; justify-content: space-between; align-items: end; gap: 2rem; padding-top: var(--section-space); padding-bottom: var(--section-space); }
.closing h2 { max-width: 760px; }
.site-footer { display: grid; grid-template-columns: 1fr auto; gap: 2rem; align-items: center; padding-top: 1.7rem; padding-bottom: 1.7rem; border-top: 1px solid var(--line); }
.site-footer p { margin: 0; color: var(--muted); font-size: var(--text-min); }

:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; }

@media (max-width: 850px) {
  .hero { grid-template-columns: 1fr; }
  .hero-copy { max-width: 680px; }
  .section-header, .demo-card { grid-template-columns: 1fr; }
  .section-header .eyebrow { grid-column: 1; }
  .demo-videos { border-right: 0; border-bottom: 1px solid var(--line); }
  .analysis-figure { grid-template-columns: 1fr; }
  .method-notes { gap: 2rem; }
  .method-notes article + article { padding-top: 2rem; }
}

@media (max-width: 620px) {
  :root { --section-space: 3.25rem; }
  .site-header { min-height: 64px; }
  .site-header nav a:not(.report-link) { display: none; }
  .site-header nav .language-switch a { display: inline-flex; }
  .site-header .report-link { padding: .5rem .7rem; font-size: var(--text-min); }
  .hero { padding-top: 2.6rem; padding-bottom: 2.6rem; }
  .hero h1 { font-size: var(--text-max); }
  .summary, .result-points, .method-notes { grid-template-columns: 1fr; }
  .summary div, .summary div:first-child, .summary div:last-child { padding: 1rem 0; border-right: 0; border-bottom: 1px solid var(--line); }.summary div:last-child { border-bottom: 0; }
  .section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
  .section-header h2, .closing h2 { font-size: var(--text-section-title); }
  .result-points { gap: 1.2rem; margin-top: 2.25rem; }
  .method-notes { margin-top: 2.5rem; }
  .method-notes h3 { font-size: var(--text-section-title); }
  .paper-figure figcaption { grid-template-columns: 1fr; gap: .75rem; }
  .demo-videos { grid-template-columns: 1fr; }
  .analysis-figure { gap: 1rem; padding: 1rem; }
  .training-steps { grid-template-columns: 1fr; }
  .evidence, .closing { align-items: flex-start; flex-direction: column; }
  .evidence a { flex: auto; }
  .site-footer { grid-template-columns: 1fr; gap: .7rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}