:root {
  --ink: #17212b;
  --muted: #5e6975;
  --line: #d8dde3;
  --paper: #fbfbf8;
  --white: #ffffff;
  --teal: #0d6b68;
  --teal-dark: #083f41;
  --red: #b64038;
  --gold: #c89b44;
  --shadow: 0 22px 60px rgba(23, 33, 43, 0.16);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Noto Serif SC", "Songti SC", "SimSun", "Microsoft YaHei", serif;
  line-height: 1.65;
}

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

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

.site-header {
  position: fixed;
  z-index: 40;
  top: 0;
  right: 0;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 72px;
  padding: 12px clamp(18px, 4vw, 56px);
  color: var(--white);
  background: rgba(12, 22, 28, 0.36);
  border-bottom: 1px solid rgba(255, 255, 255, 0.18);
  transition: background 180ms ease, box-shadow 180ms ease;
}

.site-header.is-scrolled,
.site-header.is-open {
  color: var(--ink);
  background: rgba(251, 251, 248, 0.96);
  box-shadow: 0 10px 32px rgba(23, 33, 43, 0.11);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  font-weight: 700;
  letter-spacing: 0;
}

.brand img {
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 50%;
  object-fit: cover;
}

.brand span {
  max-width: min(42vw, 430px);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 26px);
  font-size: 15px;
}

.main-nav a {
  position: relative;
  padding: 8px 0;
}

.main-nav a::after {
  position: absolute;
  right: 0;
  bottom: 2px;
  left: 0;
  height: 2px;
  content: "";
  transform: scaleX(0);
  transform-origin: center;
  background: currentColor;
  transition: transform 180ms ease;
}

.main-nav a:hover::after,
.main-nav a:focus-visible::after {
  transform: scaleX(1);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid currentColor;
  border-radius: var(--radius);
  color: inherit;
  background: transparent;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  background: currentColor;
}

.hero {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 92vh;
  padding: 118px clamp(20px, 6vw, 86px) 86px;
  color: var(--white);
  isolation: isolate;
}

.hero-media {
  position: absolute;
  inset: 0;
  z-index: -2;
  background-image: url("./assets/hero.png");
  background-position: center;
  background-size: cover;
}

.hero::before {
  position: absolute;
  inset: 0;
  z-index: -1;
  content: "";
  background: rgba(8, 18, 24, 0.58);
}

.hero-content {
  width: min(980px, 100%);
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--gold);
  font-family: "Microsoft YaHei", Arial, sans-serif;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero h1 {
  max-width: 960px;
  margin: 0;
  font-size: 68px;
  line-height: 1.08;
  letter-spacing: 0;
}

.hero-summary {
  max-width: 860px;
  margin: 28px 0 0;
  color: rgba(255, 255, 255, 0.9);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: "Microsoft YaHei", Arial, sans-serif;
  font-weight: 700;
  line-height: 1.2;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
}

.button.primary {
  color: var(--white);
  background: var(--teal);
}

.button.primary:hover,
.button.primary:focus-visible {
  background: var(--teal-dark);
}

.button.secondary {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.7);
  background: rgba(255, 255, 255, 0.08);
}

.section {
  padding: clamp(74px, 9vw, 118px) clamp(20px, 5vw, 72px);
}

.section-inner {
  width: min(1160px, 100%);
  margin: 0 auto;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 34px;
}

.section-heading h2,
.section-copy h2 {
  margin: 0;
  font-size: 44px;
  line-height: 1.16;
  letter-spacing: 0;
}

.section-heading p:not(.eyebrow),
.section-copy p {
  margin: 16px 0 0;
  color: var(--muted);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 1.05fr);
  gap: clamp(32px, 6vw, 78px);
  align-items: start;
}

.member-panel {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 18px;
}

.leader,
.member-list {
  min-height: 100%;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 12px 34px rgba(23, 33, 43, 0.08);
}

.leader span,
.member-list span,
.date {
  display: block;
  color: var(--red);
  font-family: "Microsoft YaHei", Arial, sans-serif;
  font-size: 13px;
  font-weight: 700;
}

.leader strong {
  display: block;
  margin-top: 20px;
  font-size: 34px;
}

.member-list ul {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 20px;
  padding: 0;
  margin: 18px 0 0;
  list-style: none;
  font-size: 20px;
  font-weight: 700;
}

.directions {
  background: var(--white);
}

.feature-grid,
.topic-grid,
.training-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.feature-card,
.topic-card,
.training-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
}

.feature-card img,
.training-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.feature-card div,
.topic-card,
.training-card {
  padding: 24px;
}

.feature-card h3,
.topic-card h3,
.training-card h3,
.publication-copy h3 {
  margin: 0;
  font-size: 23px;
  line-height: 1.25;
}

.feature-card p,
.topic-card p,
.training-card p {
  margin: 12px 0 0;
  color: var(--muted);
}

.topics {
  background: #edf5f3;
}

.topic-card {
  background: var(--white);
}

.topic-card a,
.training-card a,
.site-footer a,
.contact-list a {
  color: var(--teal);
  font-family: "Microsoft YaHei", Arial, sans-serif;
  font-weight: 700;
}

.topic-card a,
.training-card a {
  display: inline-flex;
  margin-top: 20px;
}

.achievement-layout {
  display: grid;
  grid-template-columns: minmax(260px, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(30px, 5vw, 64px);
  align-items: center;
}

.book-stack {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.book-stack img {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.publication-copy {
  padding: clamp(24px, 4vw, 42px);
  border-left: 4px solid var(--teal);
  background: var(--white);
}

.publication-copy ol {
  padding-left: 1.3em;
  margin: 16px 0 28px;
  color: var(--muted);
}

.publication-copy p {
  color: var(--muted);
}

.training {
  background: #292f32;
  color: var(--white);
}

.training .section-heading p:not(.eyebrow),
.training-card p {
  color: rgba(255, 255, 255, 0.76);
}

.training-card {
  border-color: rgba(255, 255, 255, 0.18);
  background: #343b3f;
}

.training-card a {
  color: #f0c96c;
}

.contact {
  background: var(--white);
}

.contact-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 1.05fr);
  gap: clamp(32px, 6vw, 70px);
}

.contact-list {
  display: grid;
  gap: 16px;
  margin-top: 28px;
}

.contact-list p {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 14px;
  margin: 0;
  color: var(--muted);
}

.contact-list strong {
  color: var(--ink);
}

.contact-form {
  display: grid;
  gap: 18px;
  padding: clamp(24px, 4vw, 36px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
}

.contact-form label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-family: "Microsoft YaHei", Arial, sans-serif;
  font-size: 14px;
  font-weight: 700;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px 14px;
  color: var(--ink);
  background: var(--white);
  font: inherit;
  resize: vertical;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: 3px solid rgba(13, 107, 104, 0.18);
  border-color: var(--teal);
}

.form-note {
  min-height: 24px;
  margin: 0;
  color: var(--teal);
  font-weight: 700;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(20px, 5vw, 72px);
  color: rgba(255, 255, 255, 0.78);
  background: #121a20;
}

.site-footer p {
  margin: 0;
}

@media (max-width: 960px) {
  .hero h1 {
    font-size: 52px;
  }

  .section-heading h2,
  .section-copy h2 {
    font-size: 38px;
  }

  .nav-toggle {
    display: block;
  }

  .main-nav {
    position: absolute;
    top: 100%;
    right: 16px;
    left: 16px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px;
    color: var(--ink);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow);
  }

  .main-nav.is-open {
    display: flex;
  }

  .main-nav a {
    padding: 12px 10px;
  }

  .split,
  .achievement-layout,
  .contact-layout {
    grid-template-columns: 1fr;
  }

  .feature-grid,
  .topic-grid,
  .training-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 620px) {
  .site-header {
    min-height: 64px;
    padding: 10px 16px;
  }

  .brand span {
    max-width: 58vw;
    font-size: 14px;
  }

  .hero {
    min-height: 94vh;
    padding: 96px 18px 54px;
  }

  .hero h1 {
    font-size: 34px;
  }

  .hero-summary {
    font-size: 15px;
  }

  .button {
    width: 100%;
  }

  .member-panel,
  .member-list ul,
  .book-stack {
    grid-template-columns: 1fr;
  }

  .contact-list p {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .site-footer {
    flex-direction: column;
  }
}