/* 欧博官网 — design system */

:root{
  --bg:#f6f4ee;
  --surface:#ffffff;
  --surface-alt:#eef1e9;
  --surface-dark:#132420;
  --ink:#171f1c;
  --ink-soft:#4b544e;
  --ink-faint:#7a8279;
  --border:#dde2d8;
  --border-strong:#c3cbc0;
  --accent:#12503f;
  --accent-dark:#0b3a2d;
  --accent-soft:#e3ede8;
  --carbon:#1c6e78;
  --carbon-soft:#e2eff0;
  --energy:#a9761f;
  --energy-soft:#f4ecd9;
  --risk:#b7522a;
  --risk-soft:#f6e6dd;
  --data:#2f5a94;
  --data-soft:#e4eaf3;
  --ok:#2c7a4b;
  --font-sans:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --font-mono:"SFMono-Regular",Consolas,"Cascadia Mono","Courier New",monospace;
  --radius:10px;
  --radius-lg:16px;
  --shadow:0 1px 2px rgba(23,31,28,.06),0 8px 24px -12px rgba(23,31,28,.12);
  --container:1180px;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
svg{max-width:100%;height:auto}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.35;margin:0 0 .6em;font-weight:700;color:var(--ink)}
p{margin:0 0 1em}
ul,ol{margin:0 0 1em;padding-left:1.4em}
.container{max-width:var(--container);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}

/* ---------- Skip link ---------- */
.skip-link{position:absolute;left:-999px;top:0;background:var(--accent);color:#fff;padding:10px 16px;z-index:200;border-radius:0 0 8px 0}
.skip-link:focus{left:0}

/* ---------- Top bar ---------- */
.topbar{background:var(--surface-dark);color:#cfe0d8;font-size:13px}
.topbar .container{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:4px 16px;min-height:36px;padding-top:6px;padding-bottom:6px}
.topbar-tags{display:flex;gap:16px;flex-wrap:wrap}
.topbar-tags span{opacity:.85}
.topbar a{color:#cfe0d8}
@media (max-width:430px){.topbar{font-size:11.5px}}

/* ---------- Header / nav ---------- */
.site-header{background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100}
.site-header .container{display:flex;align-items:center;justify-content:space-between;height:72px;gap:24px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:20px;color:var(--ink);flex-shrink:0}
.brand-mark{width:34px;height:34px;flex-shrink:0}
.brand small{display:block;font-weight:500;font-size:11px;color:var(--ink-faint);letter-spacing:.02em}
.main-nav{display:flex;align-items:center;gap:2px}
.main-nav a{
  display:inline-block;padding:10px 14px;border-radius:8px;
  color:var(--ink-soft);font-size:14.5px;font-weight:600;white-space:nowrap;
}
.main-nav a:hover{background:var(--surface-alt);color:var(--accent);text-decoration:none}
.main-nav a[aria-current="page"]{color:var(--accent);background:var(--accent-soft)}
.nav-toggle{display:none;background:none;border:1px solid var(--border-strong);border-radius:8px;padding:8px 10px;cursor:pointer}
.nav-toggle svg{width:20px;height:20px;display:block}

@media (max-width:1024px){
  .main-nav{
    position:fixed;inset:72px 0 0 0;background:var(--surface);
    flex-direction:column;align-items:stretch;padding:12px;gap:4px;
    transform:translateX(100%);transition:transform .25s ease;overflow-y:auto;
    border-top:1px solid var(--border);
  }
  .main-nav.is-open{transform:translateX(0)}
  .main-nav a{padding:14px 12px;font-size:16px;border-bottom:1px solid var(--border)}
  .nav-toggle{display:inline-flex;align-items:center;justify-content:center}
}

/* ---------- Hero ---------- */
.hero{background:linear-gradient(180deg,var(--surface) 0%,var(--surface-alt) 100%);border-bottom:1px solid var(--border)}
.hero .container{padding-top:56px;padding-bottom:56px;display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);gap:48px;align-items:center}
.hero h1{font-size:clamp(26px,3.4vw,40px);letter-spacing:-.01em}
.hero .lede{font-size:17px;color:var(--ink-soft);max-width:56ch}
.hero-tags{display:flex;flex-wrap:wrap;gap:8px;margin:18px 0 22px}
.tag{display:inline-block;font-size:12.5px;font-weight:600;padding:5px 11px;border-radius:999px;background:var(--surface);border:1px solid var(--border-strong);color:var(--ink-soft)}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;padding:13px 22px;border-radius:9px;font-weight:700;font-size:15px;border:1px solid transparent;cursor:pointer}
.btn:hover{text-decoration:none}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-dark)}
.btn-ghost{background:var(--surface);border-color:var(--border-strong);color:var(--ink)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}
.hero-figure{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:18px;box-shadow:var(--shadow)}
.hero-figure figcaption{font-size:12.5px;color:var(--ink-faint);text-align:center;margin-top:10px}

@media (max-width:900px){
  .hero .container{grid-template-columns:minmax(0,1fr);padding-top:36px;padding-bottom:36px}
  .hero-figure{order:-1;min-width:0}
}

/* ---------- Sections ---------- */
section{padding:56px 0}
.section-alt{background:var(--surface-alt)}
.section-head{max-width:760px;margin:0 auto 34px}
.section-head.left{margin-left:0}
.eyebrow{display:block;font-size:12.5px;font-weight:800;letter-spacing:.09em;text-transform:uppercase;color:var(--accent);margin-bottom:10px}
.section-head h2{font-size:clamp(22px,2.6vw,30px)}
.section-head p{color:var(--ink-soft);font-size:15.5px}

/* ---------- Agent role grid ---------- */
.agent-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.agent-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;position:relative;overflow:hidden}
.agent-card::before{content:"";position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--card-accent,var(--accent))}
.agent-card .idx{font-family:var(--font-mono);font-size:12px;color:var(--ink-faint)}
.agent-card h3{font-size:16.5px;margin:8px 0 6px}
.agent-card p{font-size:13.8px;color:var(--ink-soft);margin-bottom:0}
.agent-card a{font-size:13px;font-weight:700}
@media (max-width:1024px){.agent-grid{grid-template-columns:repeat(2,1fr)}}
@media (max-width:560px){.agent-grid{grid-template-columns:1fr}}

/* ---------- Diagram frame ---------- */
.diagram-frame{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:22px;margin:24px 0}
.diagram-frame figcaption{font-size:13px;color:var(--ink-faint);margin-top:12px;text-align:center}
.diagram-frame .diagram-title{font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--accent);margin-bottom:10px}
.diagram-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;padding-bottom:2px}
.diagram-scroll img{display:block}

/* ---------- Article blocks (homepage core 8) ---------- */
.article-list{display:flex;flex-direction:column;gap:22px}
.article-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:28px;box-shadow:var(--shadow)}
.article-meta{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-bottom:12px;font-size:13px;color:var(--ink-faint)}
.pill{display:inline-flex;align-items:center;font-size:12px;font-weight:700;padding:4px 10px;border-radius:999px}
.pill-carbon{background:var(--carbon-soft);color:var(--carbon)}
.pill-supply{background:var(--data-soft);color:var(--data)}
.pill-compliance{background:var(--energy-soft);color:var(--energy)}
.pill-report{background:var(--accent-soft);color:var(--accent)}
.pill-energy{background:var(--energy-soft);color:var(--energy)}
.pill-safety{background:var(--risk-soft);color:var(--risk)}
.pill-risk{background:var(--risk-soft);color:var(--risk)}
.pill-manager{background:var(--accent-soft);color:var(--accent)}
.article-card h3{font-size:19px;margin-bottom:12px}
.article-summary{color:var(--ink-soft);font-size:15.2px}
.core-judgment{display:flex;gap:12px;background:var(--accent-soft);border:1px solid #cfe2d8;border-radius:var(--radius);padding:14px 16px;margin:14px 0;font-size:14.3px}
.core-judgment b{color:var(--accent);flex-shrink:0}
.article-body{font-size:15.4px;color:var(--ink)}
.article-body p{margin-bottom:1.05em}
details.expand{margin-top:14px;border-top:1px dashed var(--border-strong);padding-top:14px}
details.expand > summary{cursor:pointer;font-weight:700;color:var(--accent);font-size:14.5px;list-style:none;display:inline-flex;align-items:center;gap:6px}
details.expand > summary::-webkit-details-marker{display:none}
details.expand > summary::after{content:"展开阅读完整文章";}
details.expand[open] > summary::after{content:"收起完整文章"}
details.expand > summary::before{content:"▸";transition:transform .15s}
details.expand[open] > summary::before{transform:rotate(90deg)}
.article-foot{margin-top:16px;display:flex;justify-content:flex-end}
.article-foot a{font-size:13.6px;font-weight:700}

/* ---------- Observation / essay blocks ---------- */
.essay-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px}
.essay-card h3{font-size:16.5px}
.essay-card p{font-size:14.6px;color:var(--ink-soft)}

/* ---------- Rollup / preview cards ---------- */
.rollup-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.preview-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px}
.preview-card .cat{font-size:11.5px;font-weight:800;color:var(--accent);text-transform:uppercase;letter-spacing:.06em}
.preview-card h4{font-size:15px;margin:8px 0 8px}
.preview-card p{font-size:13.4px;color:var(--ink-soft);margin-bottom:10px}
.preview-card a{font-size:13px;font-weight:700}
@media (max-width:900px){.rollup-grid{grid-template-columns:1fr 1fr}}
@media (max-width:560px){.rollup-grid{grid-template-columns:1fr}}

.rollup-block{margin-bottom:40px}
.rollup-block-head{display:flex;align-items:baseline;justify-content:space-between;gap:12px;margin-bottom:16px;flex-wrap:wrap}
.rollup-block-head h3{font-size:19px;margin:0}
.rollup-block-head a{font-size:13.6px;font-weight:700}

/* ---------- Q&A / knowledge section ---------- */
.qa-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px 28px}
.qa-item{border-bottom:1px solid var(--border);padding-bottom:14px}
.qa-item h4{font-size:15px;margin-bottom:6px;color:var(--ink)}
.qa-item h4::before{content:"Q  ";color:var(--accent);font-family:var(--font-mono);font-weight:800}
.qa-item p{font-size:13.8px;color:var(--ink-soft);margin-bottom:0}
@media (max-width:900px){.qa-grid{grid-template-columns:1fr}}

/* ---------- FAQ accordion ---------- */
.faq-list{max-width:820px;margin:0 auto;display:flex;flex-direction:column;gap:10px}
.faq-item{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}
.faq-item summary{cursor:pointer;list-style:none;padding:16px 18px;font-weight:700;font-size:15.3px;display:flex;justify-content:space-between;align-items:center;gap:12px}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:"+";font-size:20px;color:var(--accent);font-weight:400;flex-shrink:0}
.faq-item[open] summary::after{content:"–"}
.faq-item .faq-a{padding:0 18px 18px;color:var(--ink-soft);font-size:14.6px}

/* ---------- Timeline / flow steps ---------- */
.flow-steps{display:flex;flex-wrap:wrap;gap:0;align-items:stretch}
.flow-step{background:var(--surface-alt);border:1px solid var(--border);border-radius:8px;padding:10px 14px;font-size:13px;font-weight:700;color:var(--ink);transition:background .3s,border-color .3s,color .3s}
.flow-step.is-active{background:var(--accent);border-color:var(--accent);color:#fff}
.flow-arrow{display:flex;align-items:center;padding:0 8px;color:var(--ink-faint)}

/* ---------- Status pills for data example blocks ---------- */
.data-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px 18px;font-size:13.6px}
.data-card dl{display:grid;grid-template-columns:auto 1fr;gap:6px 14px;margin:0}
.data-card dt{color:var(--ink-faint);font-family:var(--font-mono);font-size:12px}
.data-card dd{margin:0;color:var(--ink)}
.status{display:inline-block;font-size:11.5px;font-weight:700;padding:2px 8px;border-radius:6px}
.status-verified{background:#e1f0e6;color:var(--ok)}
.status-pending{background:var(--energy-soft);color:var(--energy)}
.status-missing{background:var(--risk-soft);color:var(--risk)}

/* ---------- App features ---------- */
.feature-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.feature-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px}
.feature-card .num{font-family:var(--font-mono);color:var(--accent);font-size:12px}
.feature-card h4{font-size:15px;margin:6px 0}
.feature-card p{font-size:13.2px;color:var(--ink-soft);margin:0}
@media (max-width:1024px){.feature-grid{grid-template-columns:repeat(2,1fr)}}
@media (max-width:560px){.feature-grid{grid-template-columns:1fr}}

/* ---------- Tabs (simple JS-enhanced) ---------- */
.tabs{border-bottom:1px solid var(--border);display:flex;gap:4px;flex-wrap:wrap;margin-bottom:22px}
.tab-btn{background:none;border:none;padding:10px 16px;font-size:14.5px;font-weight:700;color:var(--ink-faint);cursor:pointer;border-bottom:2px solid transparent;margin-bottom:-1px}
.tab-btn[aria-selected="true"]{color:var(--accent);border-color:var(--accent)}
.tab-panel{display:none}
.tab-panel.is-active{display:block}

/* ---------- About / company ---------- */
.about-box{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:32px;max-width:900px;margin:0 auto}
.about-box h2{font-size:22px}
.about-box p{color:var(--ink-soft);font-size:15px}

/* ---------- Disclaimer ---------- */
.disclaimer{max-width:900px;margin:24px auto 0;font-size:12.8px;color:var(--ink-faint);border-top:1px solid var(--border);padding-top:18px}
.disclaimer p{margin-bottom:.6em}

/* ---------- Footer ---------- */
.site-footer{background:var(--surface-dark);color:#c6d3cb;padding:44px 0 26px}
.site-footer .container{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:32px}
.site-footer h5{color:#fff;font-size:13.5px;letter-spacing:.04em;text-transform:uppercase;margin-bottom:14px}
.site-footer a{color:#c6d3cb;font-size:13.6px}
.site-footer ul{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:9px}
.footer-brand{display:flex;align-items:center;gap:10px;color:#fff;font-weight:800;font-size:18px;margin-bottom:10px}
.footer-brand svg{width:28px;height:28px}
.footer-meta{font-size:13px;color:#93a59b;line-height:1.9}
.footer-bottom{border-top:1px solid #294038;margin-top:34px;padding-top:18px;font-size:12.5px;color:#8ba095;display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px}
@media (max-width:900px){.site-footer .container{grid-template-columns:1fr 1fr}}
@media (max-width:560px){.site-footer .container{grid-template-columns:1fr}}

/* ---------- Breadcrumb ---------- */
.breadcrumb{font-size:13px;color:var(--ink-faint);padding:14px 0}
.breadcrumb a{color:var(--ink-faint)}
.breadcrumb span{margin:0 6px}

/* ---------- Page hero (secondary pages) ---------- */
.page-hero{background:linear-gradient(180deg,var(--surface) 0%,var(--surface-alt) 100%);border-bottom:1px solid var(--border);padding:40px 0 44px}
.page-hero h1{font-size:clamp(24px,3vw,34px)}
.page-hero .lede{color:var(--ink-soft);font-size:16px;max-width:70ch}

/* ---------- Trend list ---------- */
.trend-list{display:flex;flex-direction:column;gap:14px}
.trend-item{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px 18px;display:grid;grid-template-columns:150px 1fr;gap:16px}
.trend-item .trend-tag{font-size:12.5px;font-weight:800;color:var(--data);align-self:start}
.trend-item p{font-size:14px;color:var(--ink-soft);margin:0}
@media (max-width:700px){.trend-item{grid-template-columns:1fr}}

/* ---------- App screen mock ---------- */
.app-mock{display:grid;grid-template-columns:280px minmax(0,1fr);gap:28px;align-items:center}
@media (max-width:800px){.app-mock{grid-template-columns:minmax(0,1fr)}}

/* ---------- Misc responsive ---------- */
@media (max-width:430px){
  .container{padding:0 16px}
  section{padding:40px 0}
  .article-card{padding:20px}
  .about-box{padding:22px}
}