:root {
  --bg: #ffffff;
  --bg-soft: #fbfbfa;
  --surface: #ffffff;
  --line: rgba(27, 31, 35, 0.1);
  --line-strong: rgba(27, 31, 35, 0.16);
  --ink: #16181b;
  --muted: #5f646b;
  --accent: #cf2f38;
  --accent-soft: #f5e8e7;
  --radius-lg: 22px;
  --radius-md: 16px;
  --shadow: 0 12px 32px rgba(20, 24, 28, 0.05);
  --max-width: 1080px;
  --narrow-width: 920px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Inter", "Segoe UI", sans-serif;
  background:
    linear-gradient(180deg, #ffffff 0%, var(--bg-soft) 100%);
}

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

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

code,
pre {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

h1,
h2,
h3 {
  margin: 0;
  font-family: "Newsreader", Georgia, serif;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.container {
  width: min(var(--max-width), calc(100% - 40px));
  margin: 0 auto;
}

.narrow {
  width: min(var(--narrow-width), 100%);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(12px);
  background: rgba(255, 255, 255, 0.88);
  border-bottom: 1px solid rgba(27, 31, 35, 0.06);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 72px;
}

.brand {
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  color: var(--muted);
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--ink);
}

.hero {
  padding: 56px 0 24px;
  text-align: center;
}

.venue {
  color: var(--accent);
  font-size: 1.46rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: none;
}

.venue {
  margin: 18px 0 0;
}

.step-no {
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

h1 {
  margin-top: 0;
  font-size: clamp(1.58rem, 2.75vw, 2.32rem);
  font-weight: 500;
  line-height: 1.1;
}

.authors {
  margin: 22px 0 0;
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.7;
}

.authors sup,
.affiliations sup {
  font-size: 0.72em;
  vertical-align: super;
}

.affiliations {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.65;
}

.note {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.hero-actions {
  margin-top: 28px;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
}

.action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  min-height: 56px;
  padding: 0 24px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: var(--shadow);
  font-size: 0.98rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  transition: transform 160ms ease, border-color 160ms ease;
}

.hero-actions a.action {
  background: #2c2c2c;
  color: #ffffff;
  border-color: #2c2c2c;
  box-shadow: none;
}

.action:hover {
  transform: translateY(-1px);
  border-color: var(--line-strong);
}

.hero-actions a.action:hover {
  background: #3a3a3a;
  border-color: #3a3a3a;
}

.action.muted {
  color: var(--muted);
  background: rgba(255, 255, 255, 0.58);
}

.action-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  flex: 0 0 24px;
}

.action-icon svg {
  width: 100%;
  height: 100%;
}

.content-figure,
.step-card,
.demo-item {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.content-figure figcaption,
.demo-item figcaption {
  margin-top: 12px;
  color: var(--muted);
  line-height: 1.72;
  text-align: center;
}

.section {
  padding: 38px 0 0;
}

.section-head {
  margin-bottom: 20px;
  text-align: center;
}

.section-head h2 {
  font-size: clamp(1.95rem, 3vw, 3rem);
}

.subhead {
  margin: 6px 0 16px;
  font-size: 1.55rem;
  text-align: center;
}

.body-text {
  margin: 18px auto 0;
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.9;
  text-align: left;
}

.section-head + .body-text,
.subhead + .body-text {
  margin-top: 0;
}

.center-text {
  text-align: center;
}

.logo-strip {
  display: grid;
  grid-template-columns: repeat(2, minmax(300px, 360px));
  justify-content: center;
  gap: 18px;
  margin-bottom: 26px;
}

.logo-card {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow);
  min-height: 150px;
}

.logo-card img {
  width: 320px;
  height: 108px;
  max-width: 100%;
  max-height: none;
  object-fit: contain;
}

.logo-card.pku img {
  object-position: center center;
}

.logo-card.iaii img {
  object-position: center center;
}

.content-figure {
  padding: 16px;
}

.method-figure {
  margin-bottom: 18px;
}

.compact-gap {
  margin-top: 20px;
}

.step-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 210px));
  justify-content: center;
  gap: 12px;
  margin-top: 24px;
}

.step-card {
  padding: 16px 15px 14px;
}

.step-card h3 {
  margin-top: 8px;
  font-size: 1.22rem;
}

.step-card p,
.site-footer p {
  color: var(--muted);
  line-height: 1.62;
}

.step-card p {
  margin: 6px 0 0;
  font-size: 0.93rem;
}

.demo-list {
  display: grid;
  gap: 18px;
  margin-top: 18px;
}

.demo-item {
  padding: 16px;
}

.demo-item img {
  width: 100%;
  border-radius: 12px;
  background: #ede6db;
}

.citation-note {
  margin-bottom: 18px;
}

pre {
  margin: 0;
  padding: 22px;
  overflow-x: auto;
  border-radius: var(--radius-lg);
  background: #f1f3f5;
  color: #2d3339;
  border: 1px solid rgba(27, 31, 35, 0.1);
  box-shadow: none;
}

.site-footer {
  padding: 34px 0 48px;
}

.site-footer p {
  margin: 0;
  text-align: center;
  font-size: 0.94rem;
}

@media (max-width: 900px) {
  .step-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .container {
    width: min(var(--max-width), calc(100% - 28px));
  }

  .nav {
    min-height: 64px;
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 0;
  }

  .hero {
    padding-top: 34px;
  }

  h1 {
    font-size: clamp(1.66rem, 6vw, 2.34rem);
  }

  .logo-strip {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .content-figure,
  .demo-item {
    padding: 14px;
  }
}