/* ============================================================
   领航国际官网 — 全站样式表
   设计方向：全球农业数据中心 + 卫星地球观测 + 作物生长地图
   ============================================================ */

:root{
  --c-bg: #FAF7F0;
  --c-bg-alt: #F2EDE0;
  --c-surface: #FFFFFF;
  --c-ink: #1F2A22;
  --c-ink-soft: #4B5648;
  --c-ink-faint: #7C8578;
  --c-line: #E4DFCF;
  --c-green: #17442E;
  --c-green-soft: #2C6148;
  --c-green-tint: #E8EFE6;
  --c-cyan: #1C6E7A;
  --c-cyan-tint: #E4F1F1;
  --c-soil: #7A6A52;
  --c-soil-tint: #EFE7D8;
  --c-gold: #B8862B;
  --c-gold-tint: #F6ECD4;
  --c-orange: #C1531F;
  --c-orange-tint: #FBE8DC;
  --radius-s: 6px;
  --radius-m: 12px;
  --radius-l: 20px;
  --shadow-card: 0 1px 2px rgba(23,68,46,0.06), 0 8px 24px -12px rgba(23,68,46,0.16);
  --maxw: 1180px;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

*{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
body{
  margin:0;
  font-family:var(--font);
  background:var(--c-bg);
  color:var(--c-ink);
  line-height:1.75;
  font-size:16px;
  overflow-x:hidden;
}
img{max-width:100%;display:block;height:auto;}
a{color:var(--c-green-soft);text-decoration:none;}
a:hover{text-decoration:underline;}
h1,h2,h3,h4{font-weight:700;color:var(--c-green);line-height:1.35;margin:0 0 .6em;}
h1{font-size:clamp(1.6rem,3.6vw,2.5rem);}
h2{font-size:clamp(1.3rem,2.6vw,1.85rem);}
h3{font-size:clamp(1.1rem,2vw,1.35rem);}
p{margin:0 0 1em;}
ul,ol{margin:0 0 1em;padding-left:1.3em;}
li{margin-bottom:.4em;}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px;}
section{padding:56px 0;}
.section-tight{padding:36px 0;}
.section-alt{background:var(--c-bg-alt);}
.section-deep{background:var(--c-green);color:#EFEEE3;}
.section-deep h2,.section-deep h3{color:#FBF9EF;}
.section-deep p,.section-deep li{color:#D8DECB;}
.eyebrow{
  display:inline-block;font-size:.78rem;letter-spacing:.06em;font-weight:700;
  color:var(--c-cyan);text-transform:uppercase;margin-bottom:.6em;
}
.lede{font-size:1.08rem;color:var(--c-ink-soft);max-width:760px;}

/* ---------- Header ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(250,247,240,0.92);backdrop-filter:blur(6px);
  border-bottom:1px solid var(--c-line);
}
.header-row{
  display:flex;align-items:center;justify-content:space-between;
  padding:12px 20px;max-width:var(--maxw);margin:0 auto;
}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;color:var(--c-green);font-size:1.15rem;}
.brand img{width:34px;height:34px;}
.brand small{display:block;font-weight:500;font-size:.68rem;color:var(--c-ink-faint);letter-spacing:.03em;}
.main-nav{display:flex;gap:2px;align-items:center;}
.main-nav a{
  padding:9px 14px;border-radius:999px;color:var(--c-ink-soft);font-size:.94rem;font-weight:600;
}
.main-nav a:hover,.main-nav a.active{background:var(--c-green-tint);color:var(--c-green);text-decoration:none;}
.nav-toggle{
  display:none;background:none;border:1px solid var(--c-line);border-radius:8px;
  width:40px;height:40px;cursor:pointer;position:relative;
}
.nav-toggle span,.nav-toggle span::before,.nav-toggle span::after{
  content:"";position:absolute;left:9px;right:9px;height:2px;background:var(--c-green);
}
.nav-toggle span{top:19px;}
.nav-toggle span::before{top:-6px;}
.nav-toggle span::after{top:6px;}

/* ---------- Hero ---------- */
.hero{
  padding:52px 0 40px;
  background:linear-gradient(180deg,var(--c-bg) 0%,var(--c-bg-alt) 100%);
  border-bottom:1px solid var(--c-line);
}
.hero-grid{display:grid;grid-template-columns:1.1fr 0.9fr;gap:40px;align-items:center;}
.hero h1{margin-bottom:.5em;}
.hero-tags{display:flex;flex-wrap:wrap;gap:8px;margin:18px 0;}
.hero-tags span{
  background:var(--c-surface);border:1px solid var(--c-line);color:var(--c-ink-soft);
  font-size:.78rem;padding:5px 11px;border-radius:999px;
}
.hero-art{background:var(--c-surface);border:1px solid var(--c-line);border-radius:var(--radius-l);padding:18px;box-shadow:var(--shadow-card);}
.hero-actions{display:flex;gap:12px;margin-top:20px;flex-wrap:wrap;}

.btn{
  display:inline-block;padding:11px 22px;border-radius:999px;font-weight:700;font-size:.94rem;
  border:1px solid transparent;cursor:pointer;
}
.btn-primary{background:var(--c-green);color:#fff;}
.btn-primary:hover{background:var(--c-green-soft);text-decoration:none;}
.btn-ghost{background:transparent;border-color:var(--c-green);color:var(--c-green);}
.btn-ghost:hover{background:var(--c-green-tint);text-decoration:none;}

/* ---------- Breadcrumb ---------- */
.breadcrumb{font-size:.82rem;color:var(--c-ink-faint);padding:14px 0 0;}
.breadcrumb a{color:var(--c-ink-faint);}

/* ---------- Chain diagram ---------- */
.chain-row{
  display:flex;flex-wrap:wrap;gap:10px;align-items:center;justify-content:center;
  margin:22px 0;
}
.chain-node{
  background:var(--c-surface);border:1px solid var(--c-line);border-radius:999px;
  padding:9px 16px;font-size:.86rem;font-weight:600;color:var(--c-green);
  box-shadow:var(--shadow-card);
}
.chain-arrow{color:var(--c-ink-faint);font-size:1.1rem;}

/* ---------- Cards / grids ---------- */
.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);}
.card{
  background:var(--c-surface);border:1px solid var(--c-line);border-radius:var(--radius-m);
  padding:22px;box-shadow:var(--shadow-card);
}
.card h3{margin-bottom:.4em;}
.card-icon{width:44px;height:44px;margin-bottom:12px;}

/* ---------- Featured article blocks (homepage 8) ---------- */
.feature-article{
  border:1px solid var(--c-line);background:var(--c-surface);border-radius:var(--radius-l);
  padding:30px;margin-bottom:28px;box-shadow:var(--shadow-card);
}
.feature-article .meta{
  display:flex;gap:10px;align-items:center;font-size:.8rem;color:var(--c-ink-faint);margin-bottom:10px;
}
.feature-article .meta .cat{color:var(--c-cyan);font-weight:700;}
.feature-article-media{display:flex;gap:26px;align-items:flex-start;}
.feature-article-media .fig{flex:0 0 220px;}
.feature-article-media .body{flex:1;min-width:0;}
.feature-article h2{font-size:clamp(1.15rem,2.2vw,1.5rem);}
.article-num{
  display:inline-flex;align-items:center;justify-content:center;
  width:28px;height:28px;border-radius:50%;background:var(--c-green-tint);color:var(--c-green);
  font-weight:700;font-size:.82rem;margin-right:8px;
}
figcaption{font-size:.78rem;color:var(--c-ink-faint);margin-top:8px;line-height:1.5;}

/* ---------- Observation posts ---------- */
.observation{
  border-left:3px solid var(--c-gold);background:var(--c-gold-tint);
  border-radius:0 var(--radius-m) var(--radius-m) 0;padding:20px 22px;margin-bottom:18px;
}
.observation h3{color:var(--c-green);}

/* ---------- Summary link cards for secondary content ---------- */
.summary-card{
  border:1px solid var(--c-line);background:var(--c-surface);border-radius:var(--radius-m);
  padding:20px;box-shadow:var(--shadow-card);
}
.summary-card .tag{font-size:.74rem;color:#fff;background:var(--c-cyan);padding:3px 9px;border-radius:999px;display:inline-block;margin-bottom:8px;}
.summary-card a.more{font-weight:700;}

/* ---------- Long article page ---------- */
.article-full{max-width:820px;margin:0 auto;}
.article-full h2{margin-top:1.6em;}
.article-full h3{margin-top:1.3em;color:var(--c-green-soft);}
.article-hero-svg{width:100%;border:1px solid var(--c-line);border-radius:var(--radius-m);background:var(--c-surface);padding:10px;margin:14px 0 22px;}
.callout{
  background:var(--c-cyan-tint);border-left:3px solid var(--c-cyan);border-radius:0 var(--radius-s) var(--radius-s) 0;
  padding:14px 18px;margin:1.2em 0;font-size:.96rem;
}
.callout-warn{background:var(--c-orange-tint);border-left-color:var(--c-orange);}

/* ---------- Table (commodity, price) ---------- */
.table-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;border:1px solid var(--c-line);border-radius:var(--radius-m);}
table{width:100%;border-collapse:collapse;min-width:640px;background:var(--c-surface);}
th,td{text-align:left;padding:11px 14px;border-bottom:1px solid var(--c-line);font-size:.9rem;}
th{background:var(--c-green-tint);color:var(--c-green);font-weight:700;white-space:nowrap;}
tr:last-child td{border-bottom:none;}
.trend-up{color:var(--c-orange);font-weight:700;}
.trend-down{color:var(--c-cyan);font-weight:700;}
.trend-flat{color:var(--c-ink-faint);font-weight:700;}

/* ---------- Tabs (commodity switch / weather stage / satellite timeline) ---------- */
.tabs{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:18px;}
.tab-btn{
  background:var(--c-surface);border:1px solid var(--c-line);border-radius:999px;
  padding:8px 16px;font-size:.86rem;font-weight:600;color:var(--c-ink-soft);cursor:pointer;
}
.tab-btn.active{background:var(--c-green);color:#fff;border-color:var(--c-green);}
.tab-panel{display:none;}
.tab-panel.active{display:block;}

/* ---------- Timeline (satellite) ---------- */
.timeline{display:flex;gap:14px;overflow-x:auto;padding-bottom:8px;}
.timeline-step{
  flex:0 0 150px;background:var(--c-surface);border:1px solid var(--c-line);border-radius:var(--radius-m);
  padding:14px;text-align:center;
}
.timeline-step .t-date{font-size:.74rem;color:var(--c-ink-faint);margin-bottom:6px;}
@media (max-width:600px){
  .timeline{flex-direction:column;}
  .timeline-step{flex:none;}
}

/* ---------- FAQ ---------- */
.faq-item{border-bottom:1px solid var(--c-line);}
.faq-q{
  width:100%;text-align:left;background:none;border:none;cursor:pointer;
  padding:16px 0;font-weight:700;color:var(--c-green);font-size:1rem;
  display:flex;justify-content:space-between;align-items:center;gap:12px;
}
.faq-q::after{content:"+";font-size:1.3rem;color:var(--c-ink-faint);flex:none;}
.faq-item.open .faq-q::after{content:"−";}
.faq-a{max-height:0;overflow:hidden;transition:max-height .25s ease;font-size:.94rem;color:var(--c-ink-soft);}
.faq-item.open .faq-a{max-height:800px;padding-bottom:16px;}

/* ---------- Assistant demo ---------- */
.assistant-demo{background:var(--c-surface);border:1px solid var(--c-line);border-radius:var(--radius-l);box-shadow:var(--shadow-card);overflow:hidden;}
.assistant-demo .demo-head{background:var(--c-green);color:#fff;padding:14px 20px;display:flex;align-items:center;gap:10px;font-weight:700;}
.assistant-demo .demo-body{padding:20px;}
.demo-q-list{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:16px;}
.demo-q-list button{
  background:var(--c-green-tint);border:1px solid var(--c-line);border-radius:999px;padding:7px 14px;
  font-size:.82rem;color:var(--c-green);cursor:pointer;
}
.demo-answer{background:var(--c-bg-alt);border-radius:var(--radius-m);padding:16px 18px;font-size:.92rem;}
.demo-chain{display:flex;flex-wrap:wrap;gap:6px;margin-top:10px;font-size:.76rem;color:var(--c-ink-faint);}
.demo-chain span{background:#fff;border:1px solid var(--c-line);border-radius:999px;padding:3px 10px;}

/* ---------- App feature grid ---------- */
.app-feature{display:flex;gap:14px;align-items:flex-start;padding:16px;border:1px solid var(--c-line);border-radius:var(--radius-m);background:var(--c-surface);}
.app-feature img{width:36px;height:36px;flex:none;}

/* ---------- Download block ---------- */
.download-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;}
.download-card{border:1px dashed var(--c-line);border-radius:var(--radius-m);padding:20px;text-align:center;background:var(--c-surface);}
.download-card img{width:56px;height:56px;margin:0 auto 10px;}
.notice-box{
  background:var(--c-orange-tint);border:1px solid #E9C2A6;border-radius:var(--radius-m);
  padding:16px 20px;font-size:.9rem;color:var(--c-ink-soft);margin:20px 0;
}

/* ---------- Footer ---------- */
.site-footer{background:var(--c-green);color:#CFD7C4;padding:48px 0 24px;margin-top:40px;}
.site-footer a{color:#EAF0E2;}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.4fr;gap:30px;}
.footer-grid h4{color:#fff;font-size:.9rem;margin-bottom:.8em;}
.footer-grid ul{list-style:none;padding:0;}
.footer-grid li{margin-bottom:.5em;font-size:.88rem;}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,0.15);margin-top:30px;padding-top:18px;
  font-size:.78rem;color:#A9B49B;display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px;
}
.disclaimer-box{font-size:.8rem;color:#A9B49B;line-height:1.7;margin-top:10px;}

/* ---------- Back to top ---------- */
#backTop{
  position:fixed;right:20px;bottom:24px;width:44px;height:44px;border-radius:50%;
  background:var(--c-green);color:#fff;border:none;cursor:pointer;font-size:1.1rem;
  box-shadow:0 6px 18px rgba(23,68,46,0.35);display:none;z-index:60;
}
#backTop.show{display:block;}

/* ---------- Company / about ---------- */
.about-box{display:grid;grid-template-columns:1fr 1fr;gap:30px;align-items:center;}
.fact-list{list-style:none;padding:0;margin:0;}
.fact-list li{display:flex;justify-content:space-between;border-bottom:1px dashed var(--c-line);padding:8px 0;font-size:.9rem;}
.fact-list span:first-child{color:var(--c-ink-faint);}

/* ---------- Utility ---------- */
.mt-0{margin-top:0;}
.text-center{text-align:center;}
.small{font-size:.82rem;color:var(--c-ink-faint);}
.pill{background:var(--c-cyan-tint);color:var(--c-cyan);font-size:.72rem;font-weight:700;padding:3px 10px;border-radius:999px;}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width:1024px){
  .grid-4{grid-template-columns:repeat(2,1fr);}
  .footer-grid{grid-template-columns:1fr 1fr;}
}
@media (max-width:900px){
  .main-nav{display:none;}
  .nav-toggle{display:block;}
  .site-header.nav-open .main-nav{
    display:flex;flex-direction:column;position:absolute;top:100%;left:0;right:0;
    background:var(--c-surface);border-bottom:1px solid var(--c-line);padding:10px 20px 16px;gap:4px;
  }
  .hero-grid{grid-template-columns:1fr;}
  .hero-art{order:-1;}
  .about-box{grid-template-columns:1fr;}
  .grid-3{grid-template-columns:1fr 1fr;}
  .download-grid{grid-template-columns:1fr;}
}
@media (max-width:680px){
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr;}
  .feature-article-media{flex-direction:column;}
  .feature-article-media .fig{flex:none;width:100%;}
  .footer-grid{grid-template-columns:1fr;}
  section{padding:40px 0;}
  .feature-article{padding:20px;}
  .app-feature{flex-direction:row;}
}
@media (max-width:430px){
  body{font-size:15px;}
  .container{padding:0 16px;}
}