/* ============================================================
   Seal · 密封防水与耐环境连接 — 独立设计系统
   明亮科技风 / 蓝青防水主题 / 站点级原创
   ============================================================ */

:root{
  --bg:            #f5f8fc;
  --bg-soft:       #eef4fb;
  --surface:       #ffffff;
  --surface-2:     #f0f6fc;
  --ink:           #0f1f33;
  --ink-2:         #3a4d63;
  --ink-3:         #6b7d92;
  --line:          #dde7f1;
  --line-strong:   #c4d4e4;

  --primary:       #0b5cab;   /* 深蓝：技术主色 */
  --primary-700:   #084a8e;
  --primary-900:   #05305e;
  --accent:        #00a7c4;   /* 青：防水/流体 */
  --accent-soft:   #d6f2f8;
  --glow:          #38d2ec;

  --ok:            #1f9d6b;
  --warn:          #d98a00;

  --radius:        14px;
  --radius-sm:     10px;
  --shadow:        0 10px 30px -12px rgba(11,92,171,.28);
  --shadow-soft:   0 6px 20px -10px rgba(15,31,51,.18);

  --maxw:          1200px;
  --content-w:     760px;
  --toc-w:         240px;
  --nav-h:         64px;

  --h2-inset:      0px;        /* 面包屑与正文 H2 左缘对齐基线 */
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:"PingFang SC","Microsoft YaHei","Segoe UI",system-ui,sans-serif;
  color:var(--ink);
  background:var(--bg);
  line-height:1.75;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
a{color:var(--primary);text-decoration:none}
a:hover{color:var(--primary-700)}
ul,ol{list-style:none}

/* ---------- 容器 ---------- */
.container{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 24px}
.wrap{padding-left:calc(24px + var(--h2-inset));padding-right:24px;max-width:var(--maxw);margin:0 auto}

/* ============================================================
   顶部固定导航
   ============================================================ */
.site-header{
  position:fixed;top:0;left:0;right:0;height:var(--nav-h);z-index:1000;
  background:rgba(255,255,255,.86);
  backdrop-filter:saturate(180%) blur(12px);
  border-bottom:1px solid var(--line);
}
.nav{display:flex;align-items:center;justify-content:space-between;height:var(--nav-h)}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:.3px;color:var(--ink)}
.brand .mark{
  width:30px;height:30px;border-radius:8px;
  background:linear-gradient(135deg,var(--primary),var(--accent));
  display:grid;place-items:center;color:#fff;font-size:15px;box-shadow:var(--shadow-soft);
}
.brand small{display:block;font-weight:500;font-size:11px;color:var(--ink-3);letter-spacing:.5px}

.nav-links{display:flex;align-items:center;gap:4px}
.nav-links > li{position:relative}
.nav-links > li > a{
  display:flex;align-items:center;gap:6px;
  padding:9px 14px;border-radius:999px;color:var(--ink-2);font-weight:600;font-size:15px;
}
.nav-links > li > a:hover,.nav-links > li.open > a{background:var(--surface-2);color:var(--primary)}
.caret{font-size:10px;color:var(--ink-3);transition:transform .2s}

/* 下拉：文章/产品分类 */
.dropdown{
  position:absolute;top:calc(100% + 6px);left:0;
  min-width:230px;background:var(--surface);
  border:1px solid var(--line);border-radius:var(--radius-sm);
  box-shadow:var(--shadow);padding:8px;display:none;
}
.nav-links > li.open .dropdown{display:block}
.dropdown a{display:block;padding:9px 12px;border-radius:8px;color:var(--ink-2);font-weight:500;font-size:14px}
.dropdown a:hover{background:var(--accent-soft);color:var(--primary-700)}

.nav-cta{
  margin-left:8px;padding:9px 18px;border-radius:999px;color:#fff;font-weight:700;font-size:14px;
  background:linear-gradient(135deg,var(--primary),var(--accent));box-shadow:var(--shadow-soft);
}
.nav-cta:hover{color:#fff;filter:brightness(1.05)}

/* 移动端汉堡 */
.nav-toggle{display:none;width:42px;height:42px;border:1px solid var(--line);border-radius:10px;background:var(--surface);cursor:pointer;position:relative}
.nav-toggle span{position:absolute;left:11px;right:11px;height:2px;background:var(--ink);border-radius:2px;transition:.25s}
.nav-toggle span:nth-child(1){top:14px}
.nav-toggle span:nth-child(2){top:20px}
.nav-toggle span:nth-child(3){top:26px}
.nav-toggle.active span:nth-child(1){top:20px;transform:rotate(45deg)}
.nav-toggle.active span:nth-child(2){opacity:0}
.nav-toggle.active span:nth-child(3){top:20px;transform:rotate(-45deg)}

/* 移动端展开菜单（文章/产品默认折叠） */
.mobile-menu{display:none;position:fixed;top:var(--nav-h);left:0;right:0;bottom:0;z-index:999;
  background:var(--surface);overflow-y:auto;padding:16px 20px 60px;border-top:1px solid var(--line)}
.mobile-menu.open{display:block}
.m-group{border-bottom:1px solid var(--line);padding:6px 0}
.m-group > .m-head{display:flex;align-items:center;justify-content:space-between;padding:12px 6px;font-weight:700;color:var(--ink);cursor:pointer}
.m-group > .m-head .m-caret{transition:transform .2s}
.m-group.open > .m-head .m-caret{transform:rotate(90deg)}
.m-list{max-height:0;overflow:hidden;transition:max-height .3s ease}
.m-group.open .m-list{max-height:600px}
.m-list a{display:block;padding:10px 16px;color:var(--ink-2);font-size:15px;border-radius:8px}
.m-list a:hover{background:var(--surface-2);color:var(--primary)}
.m-flat a{display:block;padding:13px 6px;font-weight:600;color:var(--ink-2)}

/* ============================================================
   通用区块
   ============================================================ */
section{padding:64px 0}
.section-head{max-width:720px;margin:0 auto 40px;text-align:center}
.eyebrow{display:inline-block;font-size:13px;font-weight:700;letter-spacing:1.5px;color:var(--accent);text-transform:uppercase;margin-bottom:12px}
.section-head h2{font-size:clamp(26px,3.4vw,38px);line-height:1.25;color:var(--ink);letter-spacing:-.5px}
.section-head p{margin-top:14px;color:var(--ink-2);font-size:17px}

.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 24px;border-radius:999px;font-weight:700;font-size:15px;cursor:pointer;border:1px solid transparent;transition:.2s}
.btn-primary{background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;box-shadow:var(--shadow-soft)}
.btn-primary:hover{color:#fff;filter:brightness(1.05);transform:translateY(-1px)}
.btn-ghost{background:var(--surface);color:var(--primary);border-color:var(--line-strong)}
.btn-ghost:hover{border-color:var(--primary);background:var(--surface-2)}

/* ============================================================
   首页 Hero
   ============================================================ */
.hero{position:relative;padding:120px 0 90px;background:
  radial-gradient(900px 500px at 80% -10%,rgba(0,167,196,.18),transparent 60%),
  radial-gradient(700px 420px at 0% 0%,rgba(11,92,171,.16),transparent 55%),
  var(--bg);overflow:hidden}
.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:48px;align-items:center}
.hero h1{font-size:clamp(32px,4.6vw,52px);line-height:1.15;letter-spacing:-1px;color:var(--ink)}
.hero h1 .hl{background:linear-gradient(120deg,var(--primary),var(--accent));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p.lead{margin-top:20px;font-size:18px;color:var(--ink-2);max-width:560px}
.hero-actions{margin-top:30px;display:flex;gap:14px;flex-wrap:wrap}
.hero-stats{margin-top:40px;display:flex;gap:30px;flex-wrap:wrap}
.hero-stats .s strong{display:block;font-size:30px;color:var(--primary);line-height:1}
.hero-stats .s span{font-size:13px;color:var(--ink-3)}

.hero-card{background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:26px;box-shadow:var(--shadow)}
.hero-card h3{font-size:17px;margin-bottom:14px;display:flex;align-items:center;gap:8px}
.ring{width:14px;height:14px;border-radius:50%;background:var(--accent);box-shadow:0 0 0 4px var(--accent-soft)}
.seal-list li{display:flex;gap:12px;padding:11px 0;border-bottom:1px dashed var(--line)}
.seal-list li:last-child{border-bottom:0}
.seal-list .k{font-weight:700;color:var(--ink);min-width:108px}
.seal-list .v{color:var(--ink-2)}

/* 信任条 */
.trustbar{border-top:1px solid var(--line);border-bottom:1px solid var(--line);background:var(--surface)}
.trustbar .container{display:flex;flex-wrap:wrap;gap:14px 36px;justify-content:center;padding:18px 24px}
.trustbar span{color:var(--ink-2);font-size:14px;display:inline-flex;align-items:center;gap:8px}
.trustbar .dot{width:7px;height:7px;border-radius:50%;background:var(--accent)}

/* 特性卡 */
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.fcard{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:26px;transition:.25s}
.fcard:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:var(--line-strong)}
.fcard .ico{width:48px;height:48px;border-radius:12px;background:var(--accent-soft);display:grid;place-items:center;font-size:22px;margin-bottom:16px}
.fcard h3{font-size:19px;margin-bottom:8px}
.fcard p{color:var(--ink-2);font-size:15px}

/* 产品/文章卡网格 */
.card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.pcard{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:.25s;display:flex;flex-direction:column}
.pcard:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:var(--line-strong)}
.pcard .thumb{height:150px;background:linear-gradient(135deg,var(--primary-900),var(--accent));position:relative;overflow:hidden}
.pcard .thumb::after{content:"";position:absolute;inset:0;background:radial-gradient(120px 120px at 30% 20%,rgba(255,255,255,.25),transparent)}
.pcard .thumb .tag{position:absolute;left:14px;top:14px;background:rgba(255,255,255,.92);color:var(--primary-700);font-size:12px;font-weight:700;padding:4px 10px;border-radius:999px}
.pcard .body{padding:18px 18px 20px;flex:1;display:flex;flex-direction:column}
.pcard h3{font-size:17px;line-height:1.4;margin-bottom:8px}
.pcard p{color:var(--ink-2);font-size:14px;flex:1}
.pcard .meta{margin-top:14px;display:flex;align-items:center;justify-content:space-between;font-size:13px;color:var(--ink-3)}
.pcard .more{color:var(--primary);font-weight:700}

/* 场景条 */
.scene-row{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.scene{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:18px}
.scene .n{font-size:13px;font-weight:800;color:var(--accent);letter-spacing:1px}
.scene h4{margin:6px 0 8px;font-size:16px}
.scene p{font-size:13px;color:var(--ink-2)}

/* CTA */
.cta-band{background:linear-gradient(120deg,var(--primary-900),var(--primary));color:#fff;border-radius:22px;padding:48px;position:relative;overflow:hidden}
.cta-band::after{content:"";position:absolute;right:-60px;top:-60px;width:320px;height:320px;border-radius:50%;background:radial-gradient(circle,rgba(56,210,236,.35),transparent 70%)}
.cta-band h2{font-size:28px;margin-bottom:10px}
.cta-band p{opacity:.9;margin-bottom:22px;max-width:560px}
.cta-band .btn-ghost{background:transparent;color:#fff;border-color:rgba(255,255,255,.5)}
.cta-band .btn-ghost:hover{background:rgba(255,255,255,.12)}

/* ============================================================
   面包屑（左缘与正文 H2 严格对齐）
   ============================================================ */
.breadcrumb{padding:18px 0 0;font-size:14px;color:var(--ink-3)}
.breadcrumb nav{display:flex;align-items:center;flex-wrap:wrap;gap:6px;padding-left:14px}
.breadcrumb a{color:var(--ink-3)}
.breadcrumb a:hover{color:var(--primary)}
.breadcrumb .sep{color:var(--line-strong)}
.breadcrumb .cur{color:var(--ink-2);font-weight:600}

/* ============================================================
   详情页布局（正文 760 + 右侧 TOC 240）
   ============================================================ */
.detail{padding:18px 0 70px}
.article-layout{display:grid;grid-template-columns:minmax(0,var(--content-w)) var(--toc-w);gap:48px;max-width:var(--maxw);margin:0 auto;padding:0 24px}
.article-main{min-width:0}
.page-wrap{max-width:880px;margin:0 auto;padding:0 24px}

.article-title{font-size:clamp(26px,3.4vw,38px);line-height:1.25;letter-spacing:-.5px;margin:8px 0 14px}
.summary-block{background:var(--surface);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:var(--radius-sm);padding:18px 20px;color:var(--ink-2);font-size:16px;margin-bottom:22px}
.keywords{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:18px}
.keywords .kw{background:var(--surface-2);border:1px solid var(--line);border-radius:999px;padding:5px 13px;font-size:13px;color:var(--ink-2)}
.update-time{font-size:13px;color:var(--ink-3);margin-bottom:18px}

.article-main h2{font-size:24px;line-height:1.35;margin:42px 0 14px;scroll-margin-top:90px;color:var(--ink);position:relative;padding-left:14px}
.article-main h2::before{content:"";position:absolute;left:0;top:6px;bottom:6px;width:4px;border-radius:4px;background:linear-gradient(var(--primary),var(--accent))}
.article-main h3{font-size:19px;margin:26px 0 10px;scroll-margin-top:90px;color:var(--ink)}
.article-main p{margin:12px 0;color:var(--ink-2)}
.article-main ul.bullets{margin:12px 0;padding-left:4px}
.article-main ul.bullets li{position:relative;padding:6px 0 6px 22px;color:var(--ink-2)}
.article-main ul.bullets li::before{content:"";position:absolute;left:4px;top:14px;width:7px;height:7px;border-radius:50%;background:var(--accent)}
.article-main strong{color:var(--ink)}

table.data{width:100%;border-collapse:collapse;margin:18px 0;font-size:14.5px;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);overflow:hidden}
table.data th,table.data td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--line)}
table.data thead th{background:var(--surface-2);color:var(--ink);font-weight:700}
table.data tbody tr:last-child td{border-bottom:0}
table.data tbody tr:hover{background:var(--accent-soft)}

.callout{background:var(--accent-soft);border:1px solid #b9e6ef;border-radius:var(--radius-sm);padding:16px 18px;margin:18px 0;color:var(--primary-900)}
.callout .t{font-weight:800;margin-bottom:4px;display:flex;gap:8px;align-items:center}

.conclusion{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px;margin:22px 0}
.conclusion .t{font-weight:800;color:var(--primary);margin-bottom:10px}
.conclusion ol{counter-reset:c;padding-left:0}
.conclusion ol li{counter-increment:c;position:relative;padding:8px 0 8px 34px;color:var(--ink-2)}
.conclusion ol li::before{content:counter(c);position:absolute;left:0;top:8px;width:24px;height:24px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;font-size:13px;font-weight:700;display:grid;place-items:center}

/* FAQ */
.faq{margin:26px 0}
.faq .faq-t{font-size:20px;font-weight:800;margin-bottom:12px}
details.faq-item{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);margin-bottom:10px;overflow:hidden}
details.faq-item summary{cursor:pointer;padding:15px 18px;font-weight:700;color:var(--ink);list-style:none;display:flex;justify-content:space-between;align-items:center}
details.faq-item summary::-webkit-details-marker{display:none}
details.faq-item summary .plus{color:var(--accent);font-size:20px;transition:.2s}
details.faq-item[open] summary .plus{transform:rotate(45deg)}
details.faq-item .a{padding:0 18px 16px;color:var(--ink-2)}

/* 相关阅读 */
.related{margin:32px 0 0;padding-top:24px;border-top:1px solid var(--line)}
.related .t{font-weight:800;margin-bottom:14px}
.related a{display:flex;gap:10px;align-items:baseline;padding:10px 0;border-bottom:1px dashed var(--line);color:var(--ink-2)}
.related a:hover{color:var(--primary)}
.related a .why{color:var(--ink-3);font-size:14px}

/* 右侧 TOC */
.toc-aside{position:sticky;top:calc(var(--nav-h) + 18px);max-height:calc(100vh - 100px);overflow-y:auto}
.toc-box{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:18px}
.toc-box .t{font-weight:800;font-size:14px;color:var(--ink-3);letter-spacing:1px;margin-bottom:12px;text-transform:uppercase}
.toc-box a{display:block;padding:7px 0;color:var(--ink-2);font-size:14px;border-left:2px solid transparent;padding-left:12px;margin-left:-1px}
.toc-box a:hover,.toc-box a.active{color:var(--primary);border-left-color:var(--accent);font-weight:600}

/* ============================================================
   列表页布局（左侧分类竖列 + 右侧内容）
   ============================================================ */
.list-layout{display:grid;grid-template-columns:240px 1fr;gap:40px;max-width:var(--maxw);margin:0 auto;padding:18px 24px 70px}
.cat-side{position:sticky;top:calc(var(--nav-h) + 18px);align-self:start}
.cat-side .t{font-size:13px;font-weight:800;color:var(--ink-3);letter-spacing:1px;margin-bottom:10px;padding-left:12px}
ul.category-list li a{display:block;padding:11px 14px;border-radius:10px;color:var(--ink-2);font-weight:600;border-left:3px solid transparent}
ul.category-list li a:hover,ul.category-list li.active a{background:var(--surface);border-left-color:var(--accent);color:var(--primary)}
.cat-content h1{font-size:30px;margin-bottom:8px}
.cat-content .desc{color:var(--ink-2);margin-bottom:24px}

/* ============================================================
   页脚
   ============================================================ */
.site-footer{background:var(--primary-900);color:#cfe0f2;margin-top:40px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:32px;padding:56px 0 36px}
.footer-grid h4{color:#fff;font-size:15px;margin-bottom:14px}
.footer-grid a{display:block;color:#bcd2ea;padding:5px 0;font-size:14px}
.footer-grid a:hover{color:#fff}
.footer-about p{font-size:14px;color:#aec6e0;margin-top:12px}
.footer-bottom{border-top:1px solid rgba(255,255,255,.12);padding:18px 0;font-size:13px;color:#9bb6d6;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}
.footer-bottom a{color:#bcd2ea}

/* ============================================================
   右侧悬浮工具胶囊
   ============================================================ */
.float-capsule{position:fixed;right:18px;top:50%;transform:translateY(-50%);z-index:1100;display:flex;flex-direction:column;gap:12px}
.cap{width:54px;height:54px;border-radius:999px;border:0;cursor:pointer;display:grid;place-items:center;
  background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;box-shadow:0 10px 24px -8px rgba(11,92,171,.6);
  position:relative;transition:transform .2s,filter .2s}
.cap:hover{transform:scale(1.06);filter:brightness(1.06)}
.cap svg{width:22px;height:22px}
.cap .lbl{position:absolute;right:64px;white-space:nowrap;background:var(--ink);color:#fff;font-size:12px;font-weight:600;padding:5px 10px;border-radius:8px;opacity:0;pointer-events:none;transition:opacity .2s}
.cap:hover .lbl{opacity:1}

/* 企业微信名片弹窗 */
.wx-modal{position:fixed;inset:0;z-index:1200;background:rgba(8,22,40,.55);backdrop-filter:blur(3px);display:none;align-items:center;justify-content:center;padding:20px}
.wx-modal.open{display:flex}
.wx-card{background:#fff;border-radius:18px;padding:18px;box-shadow:0 30px 80px -20px rgba(0,0,0,.5);width:300px}
.wx-card .wx-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px}
.wx-card .wx-head strong{font-size:15px;color:var(--ink)}
.wx-card .close{width:30px;height:30px;border-radius:8px;border:1px solid var(--line);background:var(--surface);cursor:pointer;font-size:16px;color:var(--ink-2)}
.wx-card .wx-img{width:300px;height:500px;border-radius:12px;overflow:hidden;background:var(--surface-2);display:grid;place-items:center}
.wx-card .wx-img img{width:300px;height:500px;object-fit:contain;display:block}
.wx-card .tip{font-size:12px;color:var(--ink-3);text-align:center;margin-top:10px}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width:980px){
  .hero-grid{grid-template-columns:1fr;gap:32px}
  .feature-grid,.card-grid{grid-template-columns:repeat(2,1fr)}
  .scene-row{grid-template-columns:repeat(2,1fr)}
  .article-layout{grid-template-columns:1fr}
  .toc-aside{display:none}
  .list-layout{grid-template-columns:1fr}
  .cat-side{position:static}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:680px){
  .nav-links,.nav-cta{display:none}
  .nav-toggle{display:block}
  section{padding:48px 0}
  .feature-grid,.card-grid,.scene-row{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .cta-band{padding:34px 24px}
  .hero-stats{gap:20px}
  .float-capsule{right:10px}
}