/* ==========================================================================
   星耀国际官网 style.css
   国际政治经济AI大模型 / 全球贸易政策 / 产业政策 / 制造业与宏观经济研究
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html, body, h1, h2, h3, h4, p, ul, ol, li, figure, blockquote, dl, dd { margin: 0; padding: 0; }
ul, ol { list-style: none; }
img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { overflow-x: hidden; }

/* ---------- 2. Design tokens ---------- */
:root {
  --color-bg: #faf8f3;
  --color-bg-alt: #f3efe4;
  --color-surface: #ffffff;
  --color-surface-soft: #fbfaf6;
  --color-border: #e4ded0;
  --color-border-strong: #d3cbb8;

  --color-text: #24262b;
  --color-text-secondary: #565b64;
  --color-text-muted: #82868f;
  --color-text-invert: #f5f3ec;

  --color-primary: #17335c;
  --color-primary-dark: #0e2140;
  --color-primary-soft: #e7ecf3;
  --color-cyan: #0d7b86;
  --color-cyan-soft: #e2f1f2;
  --color-orange: #b96a2c;
  --color-orange-soft: #f6e9dc;
  --color-purple: #5c5670;
  --color-purple-soft: #eae8f0;
  --color-graphite: #3c4048;

  --font-base: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Segoe UI", Roboto, sans-serif;
  --font-serif: "Songti SC", "SimSun", "Noto Serif SC", serif;

  --radius-s: 6px;
  --radius-m: 12px;
  --radius-l: 20px;
  --shadow-card: 0 1px 2px rgba(23,51,92,0.06), 0 8px 24px -12px rgba(23,51,92,0.14);
  --shadow-card-hover: 0 4px 10px rgba(23,51,92,0.10), 0 16px 32px -14px rgba(23,51,92,0.22);
  --container-w: 1180px;
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-base);
  line-height: 1.75;
  font-size: 16px;
  letter-spacing: 0.01em;
}

/* ---------- 3. Typography ---------- */
h1, h2, h3, h4 { font-family: var(--font-base); font-weight: 700; color: var(--color-primary); line-height: 1.4; }
h1 { font-size: clamp(1.6rem, 1.2rem + 1.6vw, 2.5rem); }
h2 { font-size: clamp(1.35rem, 1.1rem + 1vw, 1.9rem); }
h3 { font-size: clamp(1.15rem, 1rem + 0.6vw, 1.4rem); }
h4 { font-size: 1.05rem; }
p { color: var(--color-text-secondary); }
p + p { margin-top: 1em; }
.lede { font-size: 1.08rem; color: var(--color-text); }
.eyebrow {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.08em;
  color: var(--color-cyan); text-transform: uppercase;
}
.text-muted { color: var(--color-text-muted); }
.mono-tag { font-family: "SFMono-Regular", Consolas, monospace; font-size: 0.78rem; }

/* ---------- 4. Layout helpers ---------- */
.container { width: 100%; max-width: var(--container-w); margin: 0 auto; padding: 0 20px; }
.section { padding: 56px 0; }
.section-tight { padding: 36px 0; }
.section-alt { background: var(--color-bg-alt); }
.section-primary { background: var(--color-primary); color: var(--color-text-invert); }
.section-primary h2, .section-primary h3 { color: #fff; }
.section-primary p { color: #c7d0de; }
.section-head { max-width: 760px; margin: 0 0 32px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 900px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } .grid-3 { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 640px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }
.stack { display: flex; flex-direction: column; gap: 16px; }
.hr { height: 1px; background: var(--color-border); border: 0; margin: 40px 0; }

/* ---------- 5. Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250,248,243,0.92); backdrop-filter: saturate(160%) blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--color-primary); font-size: 1.08rem; }
.brand img, .brand svg { height: 32px; width: 32px; }
.brand-sub { display: block; font-size: 0.68rem; font-weight: 500; color: var(--color-text-muted); letter-spacing: 0.04em; }
.main-nav { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  padding: 10px 14px; border-radius: var(--radius-s); font-size: 0.92rem; font-weight: 600;
  color: var(--color-graphite); transition: background .15s, color .15s;
}
.main-nav a:hover, .main-nav a[aria-current="page"] { background: var(--color-primary-soft); color: var(--color-primary); }
.nav-toggle {
  display: none; width: 42px; height: 42px; border-radius: var(--radius-s); border: 1px solid var(--color-border);
  background: var(--color-surface); align-items: center; justify-content: center; flex-direction: column; gap: 4px;
}
.nav-toggle span { display: block; width: 20px; height: 2px; background: var(--color-primary); }
@media (max-width: 860px) {
  .main-nav {
    position: fixed; inset: 68px 0 0 0; background: var(--color-bg); flex-direction: column; align-items: stretch;
    padding: 12px 20px; gap: 2px; transform: translateY(-8px); opacity: 0; pointer-events: none; transition: opacity .18s, transform .18s;
    overflow-y: auto; border-top: 1px solid var(--color-border);
  }
  .main-nav.is-open { opacity: 1; pointer-events: auto; transform: translateY(0); }
  .main-nav a { padding: 14px 12px; font-size: 1.02rem; border-bottom: 1px solid var(--color-border); }
  .nav-toggle { display: inline-flex; }
}

/* ---------- 6. Hero ---------- */
.hero { padding: 64px 0 48px; position: relative; }
.hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center; }
@media (max-width: 900px) { .hero-grid { grid-template-columns: 1fr; gap: 32px; } }
.hero-kicker { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.chip {
  display: inline-flex; align-items: center; padding: 5px 12px; border-radius: 999px;
  font-size: 0.78rem; font-weight: 600; background: var(--color-primary-soft); color: var(--color-primary);
  border: 1px solid rgba(23,51,92,0.12);
}
.chip.cyan { background: var(--color-cyan-soft); color: var(--color-cyan); }
.chip.orange { background: var(--color-orange-soft); color: var(--color-orange); }
.chip.purple { background: var(--color-purple-soft); color: var(--color-purple); }
.hero h1 { margin-bottom: 18px; }
.hero .lede { max-width: 56ch; margin-bottom: 26px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 12px 22px; border-radius: var(--radius-s);
  font-weight: 700; font-size: 0.95rem; border: 1px solid transparent; transition: transform .15s, box-shadow .15s, background .15s;
}
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); box-shadow: var(--shadow-card-hover); }
.btn-outline { background: transparent; border-color: var(--color-border-strong); color: var(--color-primary); }
.btn-outline:hover { background: var(--color-surface); border-color: var(--color-primary); }
.hero-art { border-radius: var(--radius-l); overflow: hidden; background: var(--color-surface); border: 1px solid var(--color-border); box-shadow: var(--shadow-card); padding: 8px; }

/* ---------- 7. Cards ---------- */
.card {
  background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-m);
  padding: 24px; box-shadow: var(--shadow-card); transition: transform .15s, box-shadow .15s;
}
.card:hover { transform: translateY(-2px); box-shadow: var(--shadow-card-hover); }
.card h3 { margin-bottom: 10px; font-size: 1.05rem; }
.card p { font-size: 0.94rem; }
.card-icon { width: 44px; height: 44px; margin-bottom: 14px; }
.meta-row { display: flex; align-items: center; gap: 10px; font-size: 0.8rem; color: var(--color-text-muted); margin-bottom: 10px; }
.meta-row .dot::before { content: "·"; margin: 0 2px; }
.tag { font-size: 0.74rem; font-weight: 700; color: var(--color-cyan); text-transform: uppercase; letter-spacing: 0.05em; }

/* Feature article block (flagship long-form articles on homepage) */
.feature-article { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-l); padding: 32px; box-shadow: var(--shadow-card); }
.feature-article + .feature-article { margin-top: 28px; }
.feature-article .meta-row { margin-bottom: 14px; }
.feature-article h2 { margin-bottom: 16px; }
.feature-article .diagram-box { margin: 22px 0; }
.article-body p { font-size: 0.98rem; }
.article-more { max-height: 0; overflow: hidden; transition: max-height .35s ease; }
.article-more.is-open { max-height: none; }
.read-more-btn {
  margin-top: 16px; display: inline-flex; align-items: center; gap: 6px; font-weight: 700; font-size: 0.9rem;
  color: var(--color-cyan); background: none; border: none; padding: 0;
}
.read-more-btn::after { content: "▾"; transition: transform .2s; }
.read-more-btn[aria-expanded="true"]::after { transform: rotate(180deg); }

/* Observation notes (3 官网观察 articles) */
.observation-card { background: var(--color-purple-soft); border: 1px solid rgba(92,86,112,0.18); border-radius: var(--radius-m); padding: 26px; }
.observation-card h3 { color: var(--color-purple); }

/* Secondary summary cards linking to sub-pages */
.summary-card { display: flex; flex-direction: column; height: 100%; }
.summary-card .tag { margin-bottom: 8px; }
.summary-card .goto { margin-top: auto; padding-top: 14px; font-weight: 700; font-size: 0.86rem; color: var(--color-primary); }

/* ---------- 8. Diagram containers ---------- */
.diagram-box { background: var(--color-surface-soft); border: 1px solid var(--color-border); border-radius: var(--radius-m); padding: 20px; }
.diagram-caption { margin-top: 10px; font-size: 0.82rem; color: var(--color-text-muted); text-align: center; }
.diagram-box svg { width: 100%; height: auto; }

/* Chain / flow list (vertical causal chain) */
.chain-list { display: flex; flex-direction: column; }
.chain-item { display: flex; gap: 14px; align-items: flex-start; padding: 10px 0; }
.chain-item .node {
  flex: 0 0 auto; width: 34px; height: 34px; border-radius: 50%; background: var(--color-primary); color: #fff;
  display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 0.85rem;
}
.chain-item .body { padding-top: 4px; }
.chain-item .body strong { color: var(--color-primary); }
.chain-arrow { margin-left: 17px; width: 1px; height: 18px; background: var(--color-border-strong); }

/* Timeline (horizontal on desktop, vertical on mobile) */
.timeline { display: flex; gap: 0; overflow-x: auto; padding-bottom: 6px; }
.timeline-step { flex: 1 1 0; min-width: 150px; position: relative; padding: 18px 14px 0; border-top: 3px solid var(--color-cyan); }
.timeline-step::before { content: ""; position: absolute; top: -7px; left: 14px; width: 11px; height: 11px; border-radius: 50%; background: var(--color-cyan); }
.timeline-step h4 { font-size: 0.92rem; margin-bottom: 6px; }
.timeline-step p { font-size: 0.84rem; }
@media (max-width: 700px) {
  .timeline { flex-direction: column; overflow-x: visible; }
  .timeline-step { border-top: none; border-left: 3px solid var(--color-cyan); padding: 4px 0 18px 18px; }
  .timeline-step::before { top: 0; left: -7px; }
}

/* Funnel */
.funnel { display: flex; flex-direction: column; gap: 6px; }
.funnel-step { background: var(--color-primary-soft); border-radius: var(--radius-s); padding: 12px 18px; font-size: 0.88rem; font-weight: 600; color: var(--color-primary); text-align: center; }
.funnel-step .sub { display: block; font-weight: 400; color: var(--color-text-secondary); font-size: 0.8rem; margin-top: 2px; }
.funnel-step:nth-child(1) { width: 100%; }
.funnel-step:nth-child(2) { width: 92%; margin: 0 auto; }
.funnel-step:nth-child(3) { width: 84%; margin: 0 auto; }
.funnel-step:nth-child(4) { width: 76%; margin: 0 auto; }
.funnel-step:nth-child(5) { width: 68%; margin: 0 auto; }
.funnel-step:nth-child(6) { width: 60%; margin: 0 auto; background: var(--color-cyan-soft); color: var(--color-cyan); }
@media (max-width: 640px) { .funnel-step, .funnel-step:nth-child(n) { width: 100% !important; margin: 0; } }

/* Stack (manufacturing stack / ladder) */
.stack-diagram { display: flex; flex-direction: column-reverse; gap: 6px; }
.stack-layer { border-radius: var(--radius-s); padding: 14px 18px; font-size: 0.88rem; font-weight: 600; }
.stack-layer .sub { display: block; font-weight: 400; font-size: 0.8rem; opacity: 0.85; margin-top: 2px; }
.stack-layer:nth-child(1) { background: var(--color-orange); color: #fff; }
.stack-layer:nth-child(2) { background: var(--color-orange-soft); color: var(--color-orange); }
.stack-layer:nth-child(3) { background: var(--color-primary-soft); color: var(--color-primary); }
.stack-layer:nth-child(4) { background: var(--color-cyan-soft); color: var(--color-cyan); }
.stack-layer:nth-child(5) { background: var(--color-purple-soft); color: var(--color-purple); }
.stack-layer:nth-child(6) { background: var(--color-bg-alt); color: var(--color-graphite); border: 1px solid var(--color-border); }

/* Matrix / tabs (tariff layers, app features) */
.tabbar { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 16px; }
.tab-btn {
  padding: 9px 16px; border-radius: 999px; border: 1px solid var(--color-border-strong); background: var(--color-surface);
  font-size: 0.86rem; font-weight: 600; color: var(--color-text-secondary);
}
.tab-btn[aria-selected="true"] { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
.tab-panel { display: none; }
.tab-panel.is-active { display: block; }

/* Definition / QA list */
.qa-list { display: grid; gap: 14px; grid-template-columns: repeat(2, 1fr); }
@media (max-width: 760px) { .qa-list { grid-template-columns: 1fr; } }
.qa-item { border: 1px solid var(--color-border); border-radius: var(--radius-s); padding: 16px 18px; background: var(--color-surface); }
.qa-item dt { font-weight: 700; color: var(--color-primary); font-size: 0.92rem; margin-bottom: 6px; }
.qa-item dd { font-size: 0.88rem; color: var(--color-text-secondary); }

/* FAQ accordion */
.faq-list { border-top: 1px solid var(--color-border); }
.faq-item { border-bottom: 1px solid var(--color-border); }
.faq-q {
  width: 100%; display: flex; justify-content: space-between; align-items: center; gap: 16px;
  padding: 18px 4px; background: none; border: none; text-align: left; font-weight: 700; font-size: 0.98rem; color: var(--color-text);
}
.faq-q::after { content: "+"; font-size: 1.3rem; color: var(--color-cyan); flex: 0 0 auto; transition: transform .2s; }
.faq-q[aria-expanded="true"]::after { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .25s ease; }
.faq-a p { padding: 0 4px 18px; font-size: 0.92rem; }

/* Company / methodology / disclaimer */
.method-list { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
@media (max-width: 900px) { .method-list { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 560px) { .method-list { grid-template-columns: 1fr; } }
.method-item { text-align: center; padding: 18px 10px; }
.method-item .num { font-family: var(--font-serif); font-size: 1.6rem; color: var(--color-cyan); font-weight: 700; }
.disclaimer-box {
  background: var(--color-bg-alt); border: 1px solid var(--color-border); border-radius: var(--radius-m);
  padding: 22px 26px; font-size: 0.86rem; color: var(--color-text-secondary);
}
.disclaimer-box + .disclaimer-box { margin-top: 14px; }

/* Breadcrumb */
.breadcrumb { font-size: 0.82rem; color: var(--color-text-muted); padding: 16px 0 0; }
.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb span[aria-hidden] { margin: 0 6px; }

/* Page hero (secondary pages) */
.page-hero { padding: 40px 0 8px; }
.page-hero h1 { margin-bottom: 14px; }

/* Internal link list */
.link-list { display: flex; flex-wrap: wrap; gap: 10px; }
.link-list a {
  padding: 8px 14px; border: 1px solid var(--color-border-strong); border-radius: 999px; font-size: 0.86rem; font-weight: 600;
  color: var(--color-primary); background: var(--color-surface);
}
.link-list a:hover { background: var(--color-primary-soft); }

/* App download module */
.download-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 760px) { .download-grid { grid-template-columns: 1fr; } }
.download-card { text-align: center; padding: 26px 18px; }
.download-card svg { width: 56px; height: 56px; margin: 0 auto 14px; }
.download-status { display: inline-block; margin-top: 10px; padding: 5px 12px; border-radius: 999px; background: var(--color-bg-alt); font-size: 0.78rem; color: var(--color-text-muted); }

/* Assistant demo (ai.html) */
.assistant-panel { background: var(--color-primary-dark); border-radius: var(--radius-l); padding: 28px; color: #f2f4f8; }
.assistant-panel h3 { color: #fff; }
.assistant-q { background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.12); border-radius: var(--radius-s); padding: 12px 16px; font-size: 0.9rem; margin-bottom: 10px; }
.assistant-q::before { content: "问："; color: var(--color-cyan); font-weight: 700; }
.info-legend { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0; }
.info-legend .chip { border: none; }

/* ---------- 9. Footer ---------- */
.site-footer { background: var(--color-primary-dark); color: #cdd5e2; padding: 52px 0 26px; margin-top: 60px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
@media (max-width: 760px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px) { .footer-grid { grid-template-columns: 1fr; } }
.footer-grid h4 { color: #fff; font-size: 0.92rem; margin-bottom: 14px; }
.footer-grid ul { display: flex; flex-direction: column; gap: 9px; }
.footer-grid a, .footer-grid p { color: #a9b3c6; font-size: 0.86rem; }
.footer-grid a:hover { color: #fff; }
.footer-brand { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.footer-brand svg { height: 30px; width: 30px; }
.footer-brand strong { color: #fff; font-size: 1.05rem; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.12); margin-top: 36px; padding-top: 20px; font-size: 0.78rem; color: #8a94a8; display: flex; flex-wrap: wrap; gap: 8px 18px; justify-content: space-between; }
.beian-slot { color: #6d7891; }

/* Back to top */
.back-to-top {
  position: fixed; right: 20px; bottom: 22px; width: 46px; height: 46px; border-radius: 50%;
  background: var(--color-primary); color: #fff; display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-card-hover); border: none; opacity: 0; pointer-events: none; transition: opacity .2s, transform .2s;
  z-index: 90;
}
.back-to-top.is-visible { opacity: 1; pointer-events: auto; }
.back-to-top:hover { transform: translateY(-2px); }

/* ---------- 10. Utility ---------- */
.mt-0 { margin-top: 0 !important; }
.mt-24 { margin-top: 24px; }
.mt-40 { margin-top: 40px; }
.center { text-align: center; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }
.scroll-x { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.scroll-x::-webkit-scrollbar { height: 6px; }
.scroll-x::-webkit-scrollbar-thumb { background: var(--color-border-strong); border-radius: 4px; }

@media (max-width: 480px) {
  .section { padding: 40px 0; }
  .feature-article { padding: 22px; }
  h1 { line-height: 1.35; }
}