/* ============================================================
   迪威国际 (DIWEI International) — 全站样式表
   国际航运AI大模型 / 全球船舶港口集装箱数据平台
   ============================================================ */

:root{
  /* 品牌色板：暖白 / 深海蓝 / 港口青 / 集装箱橙 / 航线蓝绿 / 石墨灰 */
  --c-warm-white:#f7f5ef;
  --c-paper:#fffdf8;
  --c-deepsea-900:#0a1e33;
  --c-deepsea-800:#0f2c47;
  --c-deepsea-700:#153a5c;
  --c-deepsea-600:#1c4a73;
  --c-deepsea-500:#245c8f;
  --c-port-cyan:#1f8a9e;
  --c-port-cyan-light:#e4f4f3;
  --c-container-orange:#d9722c;
  --c-container-orange-light:#fbe7d4;
  --c-route-teal:#2f9e8f;
  --c-route-teal-light:#e2f3ee;
  --c-graphite-900:#1e2226;
  --c-graphite-700:#3a4148;
  --c-graphite-500:#5c6670;
  --c-graphite-300:#93a0aa;
  --c-graphite-200:#c9d2d8;
  --c-graphite-100:#e6ebee;
  --c-line:#dde3e6;
  --c-warn:#b5482a;
  --c-good:#2f7d5a;

  --font-serif-cn:"Songti SC","STSong","SimSun","Noto Serif SC",serif;
  --font-sans-cn:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Hiragino Sans GB",
    "Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --font-mono:"SFMono-Regular",Consolas,"Courier New",monospace;

  --radius-s:4px;
  --radius-m:8px;
  --radius-l:14px;
  --shadow-card:0 1px 2px rgba(10,30,51,.06), 0 6px 20px rgba(10,30,51,.07);
  --shadow-hover:0 4px 10px rgba(10,30,51,.10), 0 14px 32px rgba(10,30,51,.12);
  --maxw:1180px;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  background:var(--c-warm-white);
  color:var(--c-graphite-900);
  font-family:var(--font-sans-cn);
  font-size:16px;
  line-height:1.8;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img,svg{max-width:100%;display:block;}
a{color:var(--c-deepsea-600);text-decoration:none;}
a:hover{color:var(--c-port-cyan);}
ul,ol{margin:0;padding:0;}
h1,h2,h3,h4,p{margin:0;}
button{font-family:inherit;}

.container{max-width:var(--maxw);margin:0 auto;padding:0 24px;}
.section{padding:64px 0;}
.section-alt{background:var(--c-paper);border-top:1px solid var(--c-line);border-bottom:1px solid var(--c-line);}
.section-deep{background:var(--c-deepsea-900);color:var(--c-warm-white);}
.section-head{max-width:760px;margin-bottom:36px;}
.section-eyebrow{
  display:inline-block;font-size:13px;letter-spacing:.08em;color:var(--c-port-cyan);
  font-weight:700;margin-bottom:10px;text-transform:uppercase;
}
.section-title{font-size:28px;font-weight:800;color:var(--c-deepsea-900);line-height:1.4;}
.section-deep .section-title{color:var(--c-warm-white);}
.section-desc{margin-top:12px;color:var(--c-graphite-500);font-size:15.5px;line-height:1.85;}
.section-deep .section-desc{color:var(--c-graphite-200);}

/* ---------- 顶部导航 ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(247,245,239,.92);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--c-line);
}
.header-inner{
  max-width:var(--maxw);margin:0 auto;padding:0 24px;
  height:68px;display:flex;align-items:center;justify-content:space-between;
}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;color:var(--c-deepsea-900);font-size:18px;}
.brand .brand-logo{width:34px;height:34px;flex:none;}
.brand-sub{display:block;font-size:11px;font-weight:500;color:var(--c-graphite-500);letter-spacing:.03em;}
.main-nav{display:flex;align-items:center;gap:2px;}
.main-nav a{
  padding:9px 14px;border-radius:var(--radius-m);font-size:14.5px;font-weight:600;
  color:var(--c-graphite-700);white-space:nowrap;
}
.main-nav a:hover{background:var(--c-port-cyan-light);color:var(--c-port-cyan);}
.main-nav a[aria-current="page"]{color:var(--c-deepsea-900);background:var(--c-graphite-100);}
.nav-toggle{
  display:none;width:42px;height:42px;border:1px solid var(--c-line);border-radius:var(--radius-m);
  background:var(--c-paper);cursor:pointer;position:relative;
}
.nav-toggle span,.nav-toggle span::before,.nav-toggle span::after{
  content:"";position:absolute;left:11px;right:11px;height:2px;background:var(--c-deepsea-900);transition:transform .2s ease,opacity .2s ease;
}
.nav-toggle span{top:20px;}
.nav-toggle span::before{top:-7px;}
.nav-toggle span::after{top:7px;}
.nav-toggle[aria-expanded="true"] span{background:transparent;}
.nav-toggle[aria-expanded="true"] span::before{transform:translateY(7px) rotate(45deg);}
.nav-toggle[aria-expanded="true"] span::after{transform:translateY(-7px) rotate(-45deg);}

/* ---------- Hero ---------- */
.hero{
  background:linear-gradient(160deg,var(--c-deepsea-900) 0%,var(--c-deepsea-700) 62%,var(--c-deepsea-600) 100%);
  color:var(--c-warm-white);position:relative;overflow:hidden;
}
.hero-inner{
  max-width:var(--maxw);margin:0 auto;padding:64px 24px 56px;
  display:grid;grid-template-columns:1.15fr .85fr;gap:40px;align-items:center;
}
.hero-eyebrow{
  display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:700;
  color:var(--c-container-orange);letter-spacing:.06em;margin-bottom:16px;text-transform:uppercase;
}
.hero h1{font-size:34px;line-height:1.5;font-weight:800;color:#fff;}
.hero-lead{margin-top:18px;font-size:16.5px;line-height:1.9;color:var(--c-graphite-200);max-width:58ch;}
.hero-tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:22px;}
.hero-tags span{
  font-size:12.5px;padding:5px 11px;border-radius:999px;background:rgba(255,255,255,.08);
  border:1px solid rgba(255,255,255,.18);color:var(--c-graphite-200);
}
.hero-actions{display:flex;gap:12px;margin-top:26px;flex-wrap:wrap;}
.hero-figure{background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.12);border-radius:var(--radius-l);padding:18px;}

.btn{
  display:inline-flex;align-items:center;gap:8px;padding:12px 20px;border-radius:999px;
  font-size:14.5px;font-weight:700;border:1px solid transparent;cursor:pointer;
}
.btn-primary{background:var(--c-container-orange);color:#fff;}
.btn-primary:hover{background:#c4631f;color:#fff;}
.btn-outline{background:transparent;border-color:rgba(255,255,255,.35);color:#fff;}
.btn-outline:hover{background:rgba(255,255,255,.1);color:#fff;}
.btn-ghost{background:var(--c-graphite-100);color:var(--c-deepsea-900);}
.btn-ghost:hover{background:var(--c-graphite-200);}

/* ---------- 面包屑 ---------- */
.breadcrumb{font-size:13px;color:var(--c-graphite-500);padding:14px 0;}
.breadcrumb a{color:var(--c-graphite-500);}
.breadcrumb a:hover{color:var(--c-port-cyan);}
.breadcrumb .sep{margin:0 6px;color:var(--c-graphite-300);}

/* ---------- 文章链 / 价值链 ---------- */
.flow-chain{display:flex;flex-wrap:wrap;align-items:center;gap:0;margin-top:8px;}
.flow-node{
  background:var(--c-paper);border:1px solid var(--c-line);border-radius:var(--radius-m);
  padding:10px 14px;font-size:13.5px;font-weight:700;color:var(--c-deepsea-800);
  box-shadow:var(--shadow-card);
}
.flow-arrow{color:var(--c-port-cyan);font-size:16px;padding:0 8px;font-weight:700;}
.flow-chain.vertical{flex-direction:column;align-items:flex-start;}
.flow-chain.vertical .flow-arrow{padding:4px 0 4px 18px;}

/* ---------- 卡片网格 / 摘要卡 ---------- */
.card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:28px;}
.card-grid.cols-2{grid-template-columns:repeat(2,1fr);}
.card-grid.cols-4{grid-template-columns:repeat(4,1fr);}
.summary-card{
  background:var(--c-paper);border:1px solid var(--c-line);border-radius:var(--radius-l);
  padding:22px;box-shadow:var(--shadow-card);transition:box-shadow .18s ease,transform .18s ease;
  display:flex;flex-direction:column;gap:10px;
}
.summary-card:hover{box-shadow:var(--shadow-hover);transform:translateY(-2px);}
.summary-card .card-icon{width:40px;height:40px;}
.summary-card .card-meta{font-size:12.5px;color:var(--c-graphite-500);}
.summary-card h3{font-size:16.5px;font-weight:800;color:var(--c-deepsea-900);line-height:1.5;}
.summary-card p{font-size:14px;color:var(--c-graphite-700);line-height:1.8;}
.summary-card .card-link{font-size:13.5px;font-weight:700;color:var(--c-port-cyan);margin-top:auto;}

/* ---------- 长文章 ---------- */
.article-block{
  background:var(--c-paper);border:1px solid var(--c-line);border-radius:var(--radius-l);
  padding:32px clamp(20px,4vw,40px);box-shadow:var(--shadow-card);margin-top:24px;
}
.article-meta{
  display:flex;flex-wrap:wrap;gap:10px;align-items:center;font-size:13px;color:var(--c-graphite-500);margin-bottom:12px;
}
.article-meta .tag{
  background:var(--c-port-cyan-light);color:var(--c-port-cyan);padding:3px 10px;border-radius:999px;font-weight:700;
}
.article-title{font-size:22px;line-height:1.55;font-weight:800;color:var(--c-deepsea-900);}
.article-body{margin-top:18px;font-size:15.5px;line-height:1.95;color:var(--c-graphite-900);}
.article-body p{margin-bottom:16px;}
.article-body p:last-child{margin-bottom:0;}
.article-body h4{font-size:16px;font-weight:800;color:var(--c-deepsea-800);margin:24px 0 10px;}
.article-body strong{color:var(--c-deepsea-800);}
.article-body .pull-note{
  border-left:3px solid var(--c-container-orange);background:var(--c-container-orange-light);
  padding:12px 16px;border-radius:0 var(--radius-m) var(--radius-m) 0;font-size:14.5px;color:var(--c-graphite-900);margin:18px 0;
}
.article-figure{margin:22px 0;}
.article-figure figcaption{font-size:12.5px;color:var(--c-graphite-500);margin-top:8px;line-height:1.7;}

/* ---------- 时间线 ---------- */
.timeline{list-style:none;margin-top:16px;display:flex;flex-direction:column;gap:0;}
.timeline-step{
  position:relative;padding:0 0 22px 30px;border-left:2px solid var(--c-line);
}
.timeline-step:last-child{border-color:transparent;padding-bottom:0;}
.timeline-step::before{
  content:"";position:absolute;left:-7px;top:2px;width:12px;height:12px;border-radius:50%;
  background:var(--c-port-cyan);border:2px solid var(--c-paper);
}
.timeline-step.is-delay::before{background:var(--c-warn);}
.timeline-step.is-good::before{background:var(--c-good);}
.timeline-time{font-size:12.5px;font-weight:800;color:var(--c-port-cyan);letter-spacing:.02em;display:block;}
.timeline-step.is-delay .timeline-time{color:var(--c-warn);}
.timeline-label{font-size:15px;font-weight:700;color:var(--c-deepsea-900);display:block;margin-top:2px;}
.timeline-note{font-size:13.5px;color:var(--c-graphite-500);margin-top:3px;}
.timeline.horizontal{flex-direction:row;flex-wrap:nowrap;overflow-x:auto;gap:0;padding-bottom:10px;}
.timeline.horizontal .timeline-step{
  border-left:none;border-top:2px solid var(--c-line);padding:22px 26px 0 0;min-width:150px;flex:none;
}
.timeline.horizontal .timeline-step::before{left:0;top:-7px;}

/* ---------- 决策树 / Decision Tree ---------- */
.decision-tree{list-style:none;margin-top:16px;}
.decision-tree li{
  position:relative;padding:10px 0 10px 26px;font-size:14.5px;color:var(--c-graphite-900);
  border-left:2px dashed var(--c-graphite-200);margin-left:6px;
}
.decision-tree li::before{content:"→";position:absolute;left:-1px;top:9px;color:var(--c-port-cyan);font-weight:700;background:var(--c-paper);padding:0 2px;}
.decision-tree li:last-child{border-color:transparent;}
.decision-tree .branch-q{font-weight:700;color:var(--c-deepsea-900);}
.decision-tree .branch-a{color:var(--c-graphite-500);font-size:13.5px;}

/* ---------- 解释卡 / 术语问答 ---------- */
.explainer-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:18px 28px;margin-top:24px;}
.explainer-item h3{font-size:15.5px;font-weight:800;color:var(--c-deepsea-900);margin-bottom:6px;}
.explainer-item p{font-size:14px;color:var(--c-graphite-700);line-height:1.85;}

/* ---------- 表格 ---------- */
.table-scroll{overflow-x:auto;margin-top:18px;border:1px solid var(--c-line);border-radius:var(--radius-m);}
table.data-table{width:100%;border-collapse:collapse;min-width:560px;font-size:13.8px;background:var(--c-paper);}
table.data-table caption{text-align:left;padding:10px 14px;font-size:13px;color:var(--c-graphite-500);}
table.data-table th,table.data-table td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--c-line);}
table.data-table thead th{background:var(--c-graphite-100);color:var(--c-deepsea-900);font-weight:800;}
table.data-table tbody tr:last-child td{border-bottom:none;}

/* ---------- 统计条 ---------- */
.stat-row{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:24px;}
.stat-tile{background:var(--c-deepsea-800);color:#fff;border-radius:var(--radius-l);padding:20px;}
.stat-tile .stat-num{font-size:24px;font-weight:800;color:var(--c-container-orange);}
.stat-tile .stat-label{font-size:12.5px;color:var(--c-graphite-200);margin-top:6px;line-height:1.6;}

/* ---------- FAQ ---------- */
.faq-list{margin-top:24px;border-top:1px solid var(--c-line);}
.faq-item{border-bottom:1px solid var(--c-line);}
.faq-q{
  width:100%;text-align:left;background:none;border:none;padding:16px 4px;cursor:pointer;
  display:flex;justify-content:space-between;align-items:center;gap:16px;font-size:15px;font-weight:700;color:var(--c-deepsea-900);
}
.faq-q .faq-icon{flex:none;width:20px;height:20px;color:var(--c-port-cyan);transition:transform .2s ease;}
.faq-item[data-open="true"] .faq-icon{transform:rotate(45deg);}
.faq-a{max-height:0;overflow:hidden;transition:max-height .25s ease;}
.faq-a-inner{padding:0 4px 16px;font-size:14px;color:var(--c-graphite-700);line-height:1.85;}

/* ---------- 声明 / 免责 ---------- */
.disclaimer-box{
  background:var(--c-graphite-100);border:1px solid var(--c-line);border-radius:var(--radius-m);
  padding:18px 20px;font-size:13px;color:var(--c-graphite-500);line-height:1.85;margin-top:16px;
}
.disclaimer-box strong{color:var(--c-graphite-700);}

/* ---------- Tabs / 切换（JS 控制）---------- */
.tab-bar{display:flex;gap:6px;flex-wrap:wrap;margin-top:8px;}
.tab-btn{
  padding:9px 16px;border-radius:999px;border:1px solid var(--c-line);background:var(--c-paper);
  font-size:13.5px;font-weight:700;color:var(--c-graphite-700);cursor:pointer;
}
.tab-btn[aria-selected="true"]{background:var(--c-deepsea-800);border-color:var(--c-deepsea-800);color:#fff;}
.tab-panel{display:none;margin-top:18px;}
.tab-panel[data-active="true"]{display:block;}

/* ---------- App 功能网格 ---------- */
.feature-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:28px;}
.feature-tile{
  background:var(--c-paper);border:1px solid var(--c-line);border-radius:var(--radius-l);padding:18px;
  text-align:left;
}
.feature-tile .card-icon{width:34px;height:34px;margin-bottom:10px;}
.feature-tile h3{font-size:14.5px;font-weight:800;color:var(--c-deepsea-900);}
.feature-tile p{font-size:12.8px;color:var(--c-graphite-500);margin-top:5px;line-height:1.7;}

/* ---------- 下载入口 ---------- */
.download-row{display:flex;gap:14px;flex-wrap:wrap;margin-top:22px;}
.download-card{
  flex:1 1 220px;background:var(--c-deepsea-800);color:#fff;border-radius:var(--radius-l);
  padding:20px;display:flex;gap:14px;align-items:center;
}
.download-card svg{width:36px;height:36px;flex:none;}
.download-card h3{font-size:15px;font-weight:800;}
.download-card p{font-size:12.5px;color:var(--c-graphite-200);margin-top:4px;}

/* ---------- 公司介绍 ---------- */
.about-grid{display:grid;grid-template-columns:1.3fr .7fr;gap:36px;align-items:start;margin-top:28px;}
.about-facts{background:var(--c-paper);border:1px solid var(--c-line);border-radius:var(--radius-l);padding:22px;}
.about-facts dl{display:grid;grid-template-columns:auto 1fr;gap:10px 14px;font-size:13.8px;}
.about-facts dt{color:var(--c-graphite-500);}
.about-facts dd{margin:0;color:var(--c-deepsea-900);font-weight:700;}

/* ---------- Footer ---------- */
.site-footer{background:var(--c-deepsea-900);color:var(--c-graphite-200);padding:52px 0 26px;}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:32px;}
.footer-brand{display:flex;align-items:center;gap:10px;color:#fff;font-weight:800;font-size:17px;margin-bottom:10px;}
.footer-brand svg{width:30px;height:30px;}
.footer-col h4{font-size:13px;color:#fff;font-weight:700;margin-bottom:14px;letter-spacing:.02em;}
.footer-col ul{list-style:none;display:flex;flex-direction:column;gap:9px;}
.footer-col a{color:var(--c-graphite-300);font-size:13.5px;}
.footer-col a:hover{color:#fff;}
.footer-desc{font-size:13.3px;color:var(--c-graphite-300);line-height:1.85;max-width:44ch;}
.footer-bottom{
  margin-top:40px;padding-top:20px;border-top:1px solid rgba(255,255,255,.1);
  display:flex;flex-wrap:wrap;gap:10px;justify-content:space-between;font-size:12.5px;color:var(--c-graphite-300);
}
.footer-legal{font-size:12px;color:var(--c-graphite-500);line-height:1.8;margin-top:10px;max-width:80ch;}

/* ---------- 返回顶部 ---------- */
.back-top{
  position:fixed;right:20px;bottom:20px;width:44px;height:44px;border-radius:50%;
  background:var(--c-deepsea-800);color:#fff;border:none;cursor:pointer;display:flex;align-items:center;justify-content:center;
  box-shadow:var(--shadow-hover);opacity:0;pointer-events:none;transition:opacity .2s ease,transform .2s ease;z-index:60;
}
.back-top.is-visible{opacity:1;pointer-events:auto;}
.back-top svg{width:18px;height:18px;}

/* ---------- 迪威国际助手 对话演示 ---------- */
.assistant-demo{
  background:var(--c-deepsea-900);border-radius:var(--radius-l);padding:26px;color:#fff;
}
.assistant-msg{display:flex;gap:12px;margin-bottom:16px;align-items:flex-start;}
.assistant-msg:last-child{margin-bottom:0;}
.assistant-avatar{width:32px;height:32px;border-radius:50%;flex:none;display:flex;align-items:center;justify-content:center;background:rgba(255,255,255,.08);}
.assistant-bubble{background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.1);border-radius:var(--radius-m);padding:12px 14px;font-size:13.8px;line-height:1.8;color:var(--c-graphite-200);}
.assistant-msg.is-user .assistant-bubble{background:rgba(217,114,44,.16);border-color:rgba(217,114,44,.3);color:#fff;}

/* ---------- 架构层级图 ---------- */
.layer-stack{display:flex;flex-direction:column;gap:8px;margin-top:20px;}
.layer-row{
  display:grid;grid-template-columns:130px 1fr;gap:16px;align-items:center;
  background:var(--c-paper);border:1px solid var(--c-line);border-radius:var(--radius-m);padding:12px 16px;
}
.layer-name{font-size:13.5px;font-weight:800;color:var(--c-deepsea-900);}
.layer-items{font-size:12.8px;color:var(--c-graphite-500);}

/* ---------- 页面工具类 ---------- */
.mt-0{margin-top:0 !important;}
.text-center{text-align:center;}
.visually-hidden{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;
  clip:rect(0,0,0,0);white-space:nowrap;border:0;
}
.eyebrow-mini{font-size:12px;font-weight:700;letter-spacing:.05em;color:var(--c-route-teal);text-transform:uppercase;}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width:1024px){
  .hero-inner{grid-template-columns:1fr;}
  .hero-figure{order:-1;}
  .card-grid{grid-template-columns:repeat(2,1fr);}
  .card-grid.cols-4{grid-template-columns:repeat(2,1fr);}
  .feature-grid{grid-template-columns:repeat(2,1fr);}
  .stat-row{grid-template-columns:repeat(2,1fr);}
  .about-grid{grid-template-columns:1fr;}
  .footer-grid{grid-template-columns:1fr 1fr;}
  .explainer-grid{grid-template-columns:1fr;}
}

@media (max-width:768px){
  .main-nav{
    position:fixed;top:68px;left:0;right:0;bottom:0;background:var(--c-warm-white);
    flex-direction:column;align-items:stretch;padding:14px;gap:4px;overflow-y:auto;
    transform:translateX(100%);transition:transform .22s ease;z-index:49;
  }
  .main-nav.is-open{transform:translateX(0);}
  .main-nav a{padding:14px 12px;font-size:16px;border-bottom:1px solid var(--c-line);border-radius:0;}
  .nav-toggle{display:block;}
  .hero h1{font-size:26px;}
  .hero-inner{padding:40px 20px 40px;}
  .section{padding:44px 0;}
  .section-title{font-size:23px;}
  .card-grid,.card-grid.cols-2,.card-grid.cols-4{grid-template-columns:1fr;}
  .feature-grid{grid-template-columns:1fr;}
  .stat-row{grid-template-columns:1fr 1fr;}
  .footer-grid{grid-template-columns:1fr;gap:26px;}
  .article-block{padding:24px 18px;}
  .article-title{font-size:19px;}
  .timeline.horizontal{flex-direction:column;}
  .timeline.horizontal .timeline-step{
    border-left:2px solid var(--c-line);border-top:none;padding:0 0 22px 30px;min-width:0;
  }
  .timeline.horizontal .timeline-step::before{left:-7px;top:2px;}
  .download-row{flex-direction:column;}
}

@media (max-width:430px){
  .container{padding:0 16px;}
  .stat-row{grid-template-columns:1fr;}
}