:root{
  --bg:#0c1f2b; --bg2:#0e2a3b; --card:#ffffff; --ink:#14222c; --muted:#5d7180;
  --teal:#13b5c8; --teal-d:#0e8a99; --accent:#ff7a3c; --line:#e4ebef; --soft:#f4f8fa;
}
*{box-sizing:border-box}
body{margin:0;font-family:"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",system-ui,sans-serif;color:var(--ink);background:var(--soft);line-height:1.6}
a{color:var(--teal-d);text-decoration:none}
img{max-width:100%;display:block}
.container{max-width:1200px;margin:0 auto;padding:0 18px}
h1,h2,h3,h4{color:var(--bg2);line-height:1.25;margin:0 0 .4em}

/* header */
.site-header{background:var(--bg);position:sticky;top:0;z-index:50;box-shadow:0 2px 10px rgba(0,0,0,.15)}
.nav{display:flex;align-items:center;gap:18px;height:62px}
.brand{display:flex;align-items:center;gap:8px;color:#fff;font-weight:700;font-size:19px}
.brand img{height:30px;width:auto}
.mainnav{display:flex;gap:20px;margin-left:10px;flex:1;flex-wrap:nowrap;white-space:nowrap;align-items:center}
.mainnav a{color:#cfe3ea;font-size:14px;padding:6px 2px;border-bottom:2px solid transparent}
.mainnav a:hover{color:#fff;border-color:var(--teal)}
.navdrop{position:relative}
.navdrop .caret{font-size:10px;opacity:.75}
.dropmenu{position:absolute;top:100%;left:0;min-width:240px;background:#fff;border-radius:10px;box-shadow:0 10px 30px rgba(20,40,50,.18);padding:8px 0;display:none;z-index:80}
.navdrop:hover .dropmenu,.navdrop:focus-within .dropmenu{display:block}
.dropmenu a{display:block;padding:9px 18px;font-size:14px;color:var(--ink);border-bottom:none}
.dropmenu a:hover{background:#eef6f6;color:var(--teal-d)}
.langswitch select{background:var(--bg2);color:#fff;border:1px solid #2a4a5c;border-radius:6px;padding:6px 8px;font-size:13px}
.menubtn{display:none;background:none;border:0;color:#fff;font-size:24px;cursor:pointer}

/* hero */
.hero{position:relative;color:#fff;background:linear-gradient(120deg,rgba(8,26,36,.82),rgba(8,26,36,.45)),url('/static/uploads/site/hero.jpg') center/cover;padding:84px 0 92px}
.hero h1{color:#fff;font-size:clamp(28px,4.4vw,50px);max-width:760px}
.hero p{font-size:clamp(15px,1.7vw,19px);max-width:620px;color:#dcebef;margin:14px 0 26px}
.hero .cta{display:flex;gap:14px;flex-wrap:wrap}
.btn{display:inline-block;padding:12px 24px;border-radius:8px;font-weight:600;font-size:15px;transition:.2s}
.btn-primary{background:var(--teal);color:#04222a}
.btn-primary:hover{background:var(--teal-d)}
.btn-ghost{border:1.5px solid #fff;color:#fff}
.btn-ghost:hover{background:#fff;color:var(--bg)}

/* sections */
section{padding:56px 0}
.section-head{text-align:center;margin-bottom:34px}
.section-head h2{font-size:clamp(22px,3vw,34px)}
.section-head p{color:var(--muted);max-width:640px;margin:8px auto 0}
.grid{display:grid;gap:22px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}

/* cards */
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;overflow:hidden;box-shadow:0 4px 14px rgba(20,40,50,.05);transition:.22s;display:flex;flex-direction:column}
.card:hover{transform:translateY(-4px);box-shadow:0 10px 26px rgba(20,40,50,.12)}
.card .thumb{aspect-ratio:4/3;background:var(--soft);overflow:hidden}
.card .thumb img{width:100%;height:100%;object-fit:cover}
.card .body{padding:14px 16px 18px;display:flex;flex-direction:column;gap:6px;flex:1}
.tag{display:inline-block;font-size:11px;letter-spacing:.4px;text-transform:uppercase;color:var(--teal-d);background:#e6f7fa;padding:2px 8px;border-radius:20px;align-self:flex-start}
.card h3{font-size:16px;margin:2px 0}
.card .model{font-size:13px;color:var(--muted);font-family:ui-monospace,Menlo,monospace}
.card .excerpt{font-size:13px;color:var(--muted);flex:1}
.card .meta{display:flex;justify-content:space-between;align-items:center;font-size:13px;color:var(--muted);margin-top:6px}

/* category tiles */
.cat-tile{position:relative;border-radius:14px;overflow:hidden;min-height:150px;display:flex;align-items:flex-end;color:#fff;box-shadow:0 4px 14px rgba(20,40,50,.1)}
.cat-tile .bg{position:absolute;inset:0;background-size:cover;background-position:center;filter:brightness(.85)}
.cat-tile::before{content:'';position:absolute;inset:0;background:linear-gradient(180deg,rgba(8,28,38,.08) 25%,rgba(8,28,38,.78) 100%);z-index:1}
.cat-tile .ic{position:absolute;top:14px;left:16px;width:34px;height:34px;color:#fff;opacity:.9}
.cat-tile .lbl{position:relative;padding:16px 18px;z-index:2}
.cat-tile .lbl span{display:block;font-size:12px;opacity:.8}
.cat-tile .lbl strong{font-size:18px}

/* spec table */
.spec{width:100%;border-collapse:collapse;margin-top:8px}
.spec td{padding:9px 10px;border-bottom:1px solid var(--line);font-size:14px;vertical-align:top}
.spec td:first-child{color:var(--muted);width:42%;font-weight:600}

/* detailed introduction */
.prose h3{font-size:16px;margin:22px 0 8px;color:var(--ink);border-left:3px solid var(--teal);padding-left:10px}
.prose h3:first-child{margin-top:4px}
.feat-list{margin:6px 0 0;padding-left:18px}
.feat-list li{margin:5px 0;font-size:14px;line-height:1.6}

/* breadcrumb */
.crumbs{font-size:13px;color:var(--muted);margin:18px 0}
.crumbs a{color:var(--teal-d)}

/* product detail */
.pd{display:grid;grid-template-columns:1fr 1fr;gap:30px;align-items:start}
.pd .gallery .main{border-radius:14px;overflow:hidden;border:1px solid var(--line);aspect-ratio:4/3}
.pd .gallery .main img{width:100%;height:100%;object-fit:cover}
.thumbs{display:flex;gap:8px;margin-top:10px;flex-wrap:wrap}
.thumbs img{width:70px;height:70px;object-fit:cover;border-radius:8px;border:1px solid var(--line);cursor:pointer}
.pd h1{font-size:clamp(22px,3vw,32px)}
.pd .sub{color:var(--muted);font-family:ui-monospace,monospace;margin-bottom:14px}

/* forms */
.field{margin-bottom:14px}
.field label{display:block;font-size:13px;font-weight:600;margin-bottom:5px;color:var(--bg2)}
.field input,.field textarea,.field select{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:8px;font-size:14px;font-family:inherit}
.field textarea{min-height:90px;resize:vertical}
.note{font-size:12px;color:var(--muted)}

/* footer */
.site-footer{background:var(--bg);color:#bcd3db;margin-top:50px;padding:42px 0 18px;font-size:14px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:26px}
.site-footer h4{color:#fff;margin-bottom:10px}
.site-footer a{color:#9fd6e0}
.footcats{list-style:none;padding:0;margin:0;columns:2;font-size:13px;line-height:1.9}
.copyright{border-top:1px solid #1c3340;margin-top:26px;padding-top:14px;color:#7fa0ad;font-size:12px;text-align:center}

/* admin */
.admin-wrap{max-width:1100px;margin:30px auto;padding:0 18px}
.admin-bar{background:var(--bg);color:#fff;padding:12px 18px;display:flex;gap:14px;align-items:center;flex-wrap:wrap;border-radius:10px}
.admin-bar a{color:#bdeaf0}
.admin-bar .sp{margin-left:auto}
.stat-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin:22px 0}
.stat{background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px;text-align:center}
.stat b{display:block;font-size:30px;color:var(--teal-d)}
table.adm{width:100%;border-collapse:collapse;background:#fff;border:1px solid var(--line);border-radius:10px;overflow:hidden}
table.adm th,table.adm td{padding:10px 12px;border-bottom:1px solid var(--line);font-size:13px;text-align:left}
table.adm th{background:var(--soft);color:var(--bg2)}
table.adm img{width:54px;height:42px;object-fit:cover;border-radius:6px}
.btn-sm{padding:5px 11px;font-size:12px;border-radius:6px;border:1px solid var(--line);background:#fff;cursor:pointer}
.btn-sm.danger{color:#c0392b;border-color:#e6b3ac}
.btn-sm.ok{color:#fff;background:var(--teal);border-color:var(--teal)}
.login-box{max-width:380px;margin:80px auto;background:#fff;border:1px solid var(--line);border-radius:14px;padding:30px;box-shadow:0 8px 24px rgba(20,40,50,.1)}
.login-box h2{text-align:center}

/* misc */
.badge{display:inline-block;background:#e6f7fa;color:var(--teal-d);border-radius:20px;padding:3px 11px;font-size:12px;margin:2px 3px 2px 0}
.pagination{display:flex;gap:6px;justify-content:center;margin-top:26px;flex-wrap:wrap}
.pagination a,.pagination span{padding:7px 13px;border:1px solid var(--line);border-radius:7px;background:#fff;font-size:13px}
.pagination .cur{background:var(--teal);color:#fff;border-color:var(--teal)}
.searchbar{display:flex;gap:10px;margin-bottom:22px;flex-wrap:wrap}
.searchbar input{flex:1;min-width:200px;padding:11px 14px;border:1px solid var(--line);border-radius:9px}
.filterbar{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:18px}
.filterbar a{padding:7px 13px;border:1px solid var(--line);border-radius:20px;font-size:13px;background:#fff;color:var(--muted)}
.filterbar a.active{background:var(--teal);color:#fff;border-color:var(--teal)}

/* ===== 产品页：左侧三级分类树 + 右侧列表 ===== */
.prod-layout{display:grid;grid-template-columns:262px 1fr;gap:26px;align-items:start;margin-top:14px}
.prod-side{position:sticky;top:78px;background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px 12px;max-height:calc(100vh - 100px);overflow:auto}
.side-title{font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);font-weight:700;padding:4px 10px 10px}
.cat-tree{list-style:none;margin:0;padding:0}
.cat-tree ul{list-style:none;margin:0;padding:0}
.cat-item{margin:1px 0}
.cat-link{display:flex;align-items:center;gap:8px;padding:7px 10px;border-radius:8px;color:var(--ink);font-size:13.5px;text-decoration:none;line-height:1.25}
.cat-link:hover{background:var(--soft)}
.cat-link .cat-label{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.cat-link .cat-count{font-size:11px;color:var(--muted);background:var(--soft);border-radius:10px;padding:1px 7px;white-space:nowrap}
.cat-link .cat-ico{width:16px;height:16px;color:var(--teal-d);flex:none;display:inline-flex}
.cat-link .cat-ico svg{width:16px;height:16px}
.cat-tree.level-1 > .cat-item > .cat-link{font-weight:600;color:var(--teal-d)}
.cat-tree.level-2 > .cat-item > .cat-link{padding-left:14px;font-size:13px}
.cat-tree.level-3 > .cat-item > .cat-link{padding-left:26px;font-size:12.5px;color:var(--muted)}
.cat-item.on-path > .cat-link{background:var(--soft);color:var(--teal-d)}
.cat-item.is-active > .cat-link{background:var(--teal);color:#fff}
.cat-item.is-active > .cat-link .cat-count{background:rgba(255,255,255,.22);color:#fff}
.cat-item.is-active > .cat-link .cat-ico{color:#fff}
.all-link{font-weight:600;color:var(--teal-d);margin-bottom:6px;border-bottom:1px solid var(--line);border-radius:0;padding-bottom:10px}
.cta-band{background:linear-gradient(120deg,var(--teal-d),var(--teal));color:#fff;border-radius:16px;padding:34px;display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap;margin-top:20px}
.cta-band a{background:#fff;color:var(--teal-d)}
.case-img{aspect-ratio:16/9;border-radius:14px;overflow:hidden;background:var(--soft)}
.case-img img{width:100%;height:100%;object-fit:cover}

@media(max-width:900px){
  .grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}
  .pd{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .stat-cards{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:820px){
  .prod-layout{grid-template-columns:1fr;gap:16px}
  .prod-side{position:static;max-height:none}
}
@media(max-width:640px){
  .mainnav{display:none;position:absolute;top:62px;left:0;right:0;background:var(--bg);flex-direction:column;padding:12px 18px;gap:6px}
  .mainnav.open{display:flex}
  .menubtn{display:block;margin-left:auto}
  .dropmenu{position:static;display:block;box-shadow:none;background:transparent;padding:2px 0 2px 16px;min-width:0}
  .dropmenu a{color:#cfe3ea;font-size:13px;padding:7px 0}
  .dropmenu a:hover{background:transparent;color:#fff}
  .grid-3,.grid-4,.grid-2{grid-template-columns:1fr}
}