/* ==========================================================================
   领航国际官网 style.css
   国际ESG AI大模型 / 企业碳足迹 / 供应链社会责任 教育科技官网
   ========================================================================== */

:root {
  --c-bg: #F7F4EC;
  --c-bg-alt: #EFEADB;
  --c-surface: #FFFFFF;
  --c-surface-soft: #F2EFE5;
  --c-ink: #22271F;
  --c-ink-soft: #4B5148;
  --c-graphite: #565F5A;
  --c-line: #DCD5C2;
  --c-line-soft: #E9E4D4;
  --c-forest: #1E3B2C;
  --c-forest-dark: #142A1F;
  --c-forest-soft: #E4EBE3;
  --c-teal: #1C6E7E;
  --c-teal-soft: #E1EEF0;
  --c-nature: #3C8873;
  --c-nature-soft: #E4F0EA;
  --c-orange: #C06A2C;
  --c-orange-soft: #F5E6D8;
  --c-amber: #A6812A;
  --c-red: #A6402F;
  --c-red-soft: #F3E2DD;
  --radius-s: 6px;
  --radius-m: 12px;
  --radius-l: 20px;
  --shadow-card: 0 1px 2px rgba(20, 30, 22, 0.06), 0 8px 24px rgba(20, 30, 22, 0.06);
  --font-base: "PingFang SC", "Microsoft YaHei UI", "Microsoft YaHei", "Noto Sans SC", "Hiragino Sans GB", "Segoe UI", sans-serif;
  --font-num: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --maxw: 1160px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--c-bg);
  color: var(--c-ink);
  font-family: var(--font-base);
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: var(--c-teal); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { color: var(--c-forest-dark); line-height: 1.4; margin: 0 0 .6em; font-weight: 700; }
p { margin: 0 0 1em; }
ul, ol { margin: 0 0 1em; padding-left: 1.4em; }
li { margin-bottom: .4em; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0; padding: 0; margin: -1px;
}
section { padding: 64px 0; }
section.tight { padding: 40px 0; }
.section-alt { background: var(--c-bg-alt); }
.section-forest { background: var(--c-forest); color: #EFEFE6; }
.section-forest h2, .section-forest h3 { color: #FFFFFF; }
.section-forest a { color: #C9E4CE; }

/* ---------- eyebrow / kicker ---------- */
.eyebrow {
  display: inline-block;
  font-size: .8rem;
  letter-spacing: .06em;
  color: var(--c-teal);
  background: var(--c-teal-soft);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 14px;
  font-weight: 600;
}
.section-head { max-width: 760px; margin-bottom: 36px; }
.section-head h2 { font-size: clamp(1.5rem, 1.2rem + 1.2vw, 2rem); }
.section-head p { color: var(--c-graphite); font-size: 1.02rem; }

/* ---------- header / nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(247, 244, 236, 0.94);
  backdrop-filter: saturate(140%) blur(6px);
  border-bottom: 1px solid var(--c-line);
}
.site-header .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 72px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand img { height: 34px; width: auto; }
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-text strong { font-size: 1.06rem; color: var(--c-forest-dark); }
.brand-text span { font-size: .68rem; color: var(--c-graphite); letter-spacing: .04em; }

.main-nav { display: flex; gap: 4px; }
.main-nav a {
  color: var(--c-ink-soft); font-size: .95rem; padding: 10px 14px;
  border-radius: 8px; text-decoration: none;
}
.main-nav a:hover, .main-nav a[aria-current="page"] {
  background: var(--c-forest-soft); color: var(--c-forest-dark); text-decoration: none;
}
.nav-toggle {
  display: none; background: none; border: 1px solid var(--c-line); border-radius: 8px;
  padding: 8px 10px; cursor: pointer;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  display: block; width: 20px; height: 2px; background: var(--c-forest-dark); position: relative;
}
.nav-toggle span::before, .nav-toggle span::after { content: ""; position: absolute; }
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }

/* ---------- hero ---------- */
.hero { padding: 56px 0 40px; }
.hero-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; }
.hero h1 {
  font-size: clamp(1.7rem, 1.2rem + 2.2vw, 2.5rem);
  margin-bottom: .5em;
}
.hero-lede { font-size: 1.08rem; color: var(--c-ink-soft); max-width: 560px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 24px; }
.hero-media { border-radius: var(--radius-l); overflow: hidden; background: var(--c-surface); box-shadow: var(--shadow-card); padding: 12px; }
.hero-stats { display: flex; gap: 24px; margin-top: 28px; flex-wrap: wrap; }
.hero-stats div { min-width: 120px; }
.hero-stats strong { display: block; font-size: 1.1rem; color: var(--c-forest); }
.hero-stats span { font-size: .84rem; color: var(--c-graphite); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 22px; border-radius: 999px; font-size: .96rem; font-weight: 600;
  border: 1px solid transparent; cursor: pointer; text-decoration: none;
}
.btn-primary { background: var(--c-forest); color: #fff; }
.btn-primary:hover { background: var(--c-forest-dark); text-decoration: none; }
.btn-outline { background: transparent; border-color: var(--c-forest); color: var(--c-forest-dark); }
.btn-outline:hover { background: var(--c-forest-soft); text-decoration: none; }
.btn-ghost { background: var(--c-surface); border-color: var(--c-line); color: var(--c-ink-soft); }

/* ---------- chain / flow diagram row ---------- */
.chain-row {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center; justify-content: flex-start;
  margin: 28px 0;
}
.chain-node {
  background: var(--c-surface); border: 1px solid var(--c-line); border-radius: var(--radius-m);
  padding: 10px 16px; font-size: .88rem; color: var(--c-forest-dark); font-weight: 600;
  box-shadow: var(--shadow-card);
}
.chain-arrow { color: var(--c-teal); font-size: 1.1rem; }

/* ---------- article highlight cards (homepage 8 flagship) ---------- */
.flagship-list { display: flex; flex-direction: column; gap: 28px; }
.flagship-card {
  display: grid; grid-template-columns: 280px 1fr; gap: 28px;
  background: var(--c-surface); border: 1px solid var(--c-line-soft); border-radius: var(--radius-l);
  padding: 28px; box-shadow: var(--shadow-card);
}
.flagship-card .fig { border-radius: var(--radius-m); overflow: hidden; background: var(--c-surface-soft); align-self: start; }
.flagship-meta { display: flex; gap: 10px; align-items: center; font-size: .82rem; color: var(--c-graphite); margin-bottom: 10px; flex-wrap: wrap; }
.flagship-meta .tag { background: var(--c-forest-soft); color: var(--c-forest-dark); padding: 3px 10px; border-radius: 999px; font-weight: 600; }
.flagship-card h3 { font-size: 1.28rem; margin-bottom: .5em; }
.flagship-card .lede { color: var(--c-ink-soft); }
.flagship-card .body-preview { color: var(--c-ink-soft); border-top: 1px dashed var(--c-line); padding-top: 14px; margin-top: 14px; }
.flagship-card .readmore { display: inline-block; margin-top: 10px; font-weight: 600; }

/* ---------- observation posts ---------- */
.observe-list { display: flex; flex-direction: column; gap: 22px; }
.observe-card {
  background: var(--c-surface-soft); border-left: 4px solid var(--c-nature);
  border-radius: 0 var(--radius-m) var(--radius-m) 0; padding: 22px 26px;
}
.observe-card h3 { font-size: 1.08rem; }
.observe-meta { font-size: .8rem; color: var(--c-graphite); margin-bottom: 8px; }

/* ---------- generic article card grid (secondary summaries) ---------- */
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.card-grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.mini-card {
  background: var(--c-surface); border: 1px solid var(--c-line-soft); border-radius: var(--radius-m);
  padding: 22px; box-shadow: var(--shadow-card); display: flex; flex-direction: column;
}
.mini-card .icon { width: 44px; height: 44px; margin-bottom: 14px; }
.mini-card h3 { font-size: 1.04rem; margin-bottom: .5em; }
.mini-card p { color: var(--c-ink-soft); font-size: .94rem; flex: 1; }
.mini-card .link { font-size: .88rem; font-weight: 600; margin-top: 10px; }
.mini-card .tag-row { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 10px; }
.mini-card .tag-row span { font-size: .72rem; background: var(--c-teal-soft); color: var(--c-teal); padding: 2px 9px; border-radius: 999px; }

/* ---------- long-form article (in-page, secondary pages) ---------- */
.article {
  background: var(--c-surface); border: 1px solid var(--c-line-soft); border-radius: var(--radius-l);
  padding: 36px; box-shadow: var(--shadow-card); margin-bottom: 32px;
}
.article header { margin-bottom: 20px; }
.article .article-meta { font-size: .82rem; color: var(--c-graphite); display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 8px; }
.article .article-meta .tag { background: var(--c-forest-soft); color: var(--c-forest-dark); padding: 2px 10px; border-radius: 999px; font-weight: 600; }
.article h2 { font-size: 1.4rem; }
.article h3 { font-size: 1.12rem; margin-top: 1.6em; }
.article p { color: var(--c-ink); }
.article .figure { margin: 20px 0; background: var(--c-surface-soft); border-radius: var(--radius-m); padding: 16px; }
.article .figure figcaption { font-size: .85rem; color: var(--c-graphite); margin-top: 10px; text-align: center; }
.article .callout {
  background: var(--c-teal-soft); border-left: 4px solid var(--c-teal); border-radius: var(--radius-s);
  padding: 14px 18px; margin: 18px 0; font-size: .95rem; color: var(--c-forest-dark);
}
.article .callout.warn { background: var(--c-orange-soft); border-left-color: var(--c-orange); }

/* ---------- data quality / tags ---------- */
.dq { display: inline-flex; align-items: center; gap: 6px; font-size: .78rem; font-weight: 700; padding: 3px 10px; border-radius: 999px; }
.dq-high { background: var(--c-nature-soft); color: #235B48; }
.dq-medium { background: var(--c-orange-soft); color: #8A4A1D; }
.dq-low { background: var(--c-red-soft); color: #82291B; }
.dq-missing { background: #EDEAE0; color: #6B665A; border: 1px dashed #ABA48F; }

/* ---------- tables ---------- */
.table-wrap { overflow-x: auto; margin: 20px 0; border: 1px solid var(--c-line-soft); border-radius: var(--radius-m); }
table { border-collapse: collapse; width: 100%; min-width: 520px; font-size: .92rem; }
th, td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--c-line-soft); vertical-align: top; }
th { background: var(--c-surface-soft); color: var(--c-forest-dark); font-weight: 700; }
tr:last-child td { border-bottom: none; }

/* ---------- FAQ ---------- */
.faq-list { display: flex; flex-direction: column; gap: 10px; }
.faq-item { background: var(--c-surface); border: 1px solid var(--c-line-soft); border-radius: var(--radius-m); overflow: hidden; }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; cursor: pointer;
  padding: 16px 20px; font-size: .98rem; font-weight: 600; color: var(--c-forest-dark);
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
}
.faq-q .plus { font-size: 1.2rem; color: var(--c-teal); transition: transform .2s ease; flex-shrink: 0; }
.faq-item[open] .faq-q .plus { transform: rotate(45deg); }
.faq-a { padding: 0 20px 18px; color: var(--c-ink-soft); font-size: .93rem; }
.faq-item > summary::-webkit-details-marker { display: none; }

/* ---------- materiality matrix (interactive demo) ---------- */
.matrix-wrap { background: var(--c-surface); border: 1px solid var(--c-line-soft); border-radius: var(--radius-l); padding: 24px; }
.matrix-tabs { display: flex; gap: 8px; margin-bottom: 18px; flex-wrap: wrap; }
.matrix-tabs button {
  padding: 8px 16px; border-radius: 999px; border: 1px solid var(--c-line); background: var(--c-surface-soft);
  cursor: pointer; font-size: .88rem; color: var(--c-ink-soft);
}
.matrix-tabs button[aria-selected="true"] { background: var(--c-forest); color: #fff; border-color: var(--c-forest); }
.matrix-panel { display: none; }
.matrix-panel.active { display: block; }

/* ---------- scope demo tabs ---------- */
.demo-tabs { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
.demo-tabs button {
  padding: 9px 18px; border-radius: 10px; border: 1px solid var(--c-line); background: var(--c-surface);
  cursor: pointer; font-weight: 600; font-size: .9rem; color: var(--c-ink-soft);
}
.demo-tabs button[aria-selected="true"] { background: var(--c-teal); color: #fff; border-color: var(--c-teal); }
.demo-panel { display: none; background: var(--c-surface); border: 1px solid var(--c-line-soft); border-radius: var(--radius-m); padding: 20px; }
.demo-panel.active { display: block; }

/* ---------- footer ---------- */
.site-footer { background: var(--c-forest-dark); color: #D8DED6; padding: 56px 0 28px; margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
.footer-grid h4 { color: #fff; font-size: .92rem; margin-bottom: 14px; }
.footer-grid a { color: #B9C4B7; font-size: .88rem; display: block; margin-bottom: 8px; }
.footer-grid a:hover { color: #fff; }
.footer-brand p { color: #A9B5A6; font-size: .86rem; max-width: 340px; }
.footer-legal {
  border-top: 1px solid rgba(255,255,255,.12); margin-top: 40px; padding-top: 22px;
  font-size: .78rem; color: #93A091; line-height: 1.9;
}
.footer-legal .icp { min-height: 1.2em; }

/* ---------- breadcrumb ---------- */
.breadcrumb { font-size: .84rem; color: var(--c-graphite); margin: 20px 0 4px; }
.breadcrumb a { color: var(--c-graphite); }

/* ---------- page hero (secondary pages) ---------- */
.page-hero { padding: 44px 0 8px; }
.page-hero h1 { font-size: clamp(1.5rem, 1.2rem + 1.4vw, 2.1rem); }
.page-hero .lede { color: var(--c-ink-soft); max-width: 720px; font-size: 1.02rem; }
.page-hero .status-note {
  display: inline-flex; align-items: center; gap: 8px; font-size: .82rem; color: var(--c-graphite);
  background: var(--c-surface-soft); border: 1px solid var(--c-line-soft); border-radius: 999px;
  padding: 6px 14px; margin-top: 16px;
}

/* ---------- back to top ---------- */
.to-top {
  position: fixed; right: 20px; bottom: 20px; width: 44px; height: 44px; border-radius: 50%;
  background: var(--c-forest); color: #fff; border: none; cursor: pointer; font-size: 1.1rem;
  box-shadow: var(--shadow-card); display: none; align-items: center; justify-content: center; z-index: 90;
}
.to-top.show { display: flex; }

/* ---------- utility ---------- */
.mt-0 { margin-top: 0; }
.text-center { text-align: center; }
.stack { display: flex; flex-direction: column; gap: 16px; }
.pill-row { display: flex; gap: 8px; flex-wrap: wrap; }
.pill { font-size: .78rem; background: var(--c-surface-soft); border: 1px solid var(--c-line-soft); padding: 4px 12px; border-radius: 999px; color: var(--c-graphite); }

/* ---------- network / supplier diagram list ---------- */
.tier-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.tier-card { background: var(--c-surface); border: 1px solid var(--c-line-soft); border-radius: var(--radius-m); padding: 18px; }
.tier-card h4 { font-size: .95rem; color: var(--c-forest); margin-bottom: 6px; }
.tier-card p { font-size: .86rem; color: var(--c-graphite); margin: 0; }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; }
  .flagship-card { grid-template-columns: 220px 1fr; }
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .tier-list { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .main-nav { display: none; }
  .nav-toggle { display: inline-flex; flex-direction: column; justify-content: center; align-items: center; }
  .site-header.open .main-nav {
    display: flex; position: absolute; top: 72px; left: 0; right: 0; background: var(--c-bg);
    flex-direction: column; padding: 12px 24px 20px; border-bottom: 1px solid var(--c-line); gap: 2px;
  }
  .flagship-card { grid-template-columns: 1fr; }
  .flagship-card .fig { max-width: 220px; }
  .card-grid, .card-grid.cols-2 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  section { padding: 44px 0; }
  .tier-list { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .hero { padding: 36px 0 24px; }
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .article { padding: 22px; }
  .flagship-card { padding: 18px; }
}