:root{--ocean:#0C6B8A;--ocean-deep:#08465A;--ocean-dark:#062E3C;--ice:#EAF5FA;
--ice-2:#F3FAFD;--card:#FFFFFF;--ink:#0E2A33;--ink-soft:#5A7480;--line:#D6E9F1;
--aurora:#12A79B;--sky:#7FC9E8;--sky-soft:#C4E5F3;--beluga:#FFFFFF;--gold:#F2B33C}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
color:var(--ink);background:var(--ice);line-height:1.75;font-size:16px}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{max-width:1140px;margin:0 auto;padding:0 24px}
.accent{color:var(--ocean)}
h1,h2,h3{line-height:1.25;font-weight:700}
h1{font-size:clamp(34px,5vw,54px)}
h2{font-size:clamp(24px,3.4vw,36px)}
h3{font-size:19px}

/* 顶部冰层 + 导航 */
.ice-shelf{background:linear-gradient(90deg,var(--ocean-dark),var(--ocean-deep));color:#DCF2FA;font-size:13px;padding:7px 0;text-align:center}
.ice-shelf-inner{opacity:.92}
.topnav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.86);backdrop-filter:blur(12px);
border-bottom:1px solid var(--line)}
.topnav-inner{display:flex;align-items:center;gap:26px;height:68px}
.brand{display:flex;align-items:center;gap:10px}
.brand-mark{flex:0 0 auto}
.brand-word{display:flex;flex-direction:column;line-height:1.1}
.brand-name{font-size:20px;font-weight:800;letter-spacing:.5px}
.brand-name em{font-style:normal;color:var(--ocean)}
.brand-sub{font-size:11px;color:var(--ink-soft);letter-spacing:1px}
.nav-links{display:flex;gap:24px;margin-left:auto;align-items:center}
.nav-item{position:relative}
.nav-link{font-size:15px;color:var(--ink);opacity:.85;padding:6px 0;border-bottom:2px solid transparent;
display:inline-flex;align-items:center;gap:4px}
.nav-link:hover,.nav-link.on{color:var(--ocean);opacity:1;border-color:var(--aurora)}
.caret{font-size:11px;opacity:.6;transition:.2s}
.nav-item:hover .caret{transform:rotate(180deg)}
.dropdown{position:absolute;top:100%;left:50%;transform:translateX(-50%);min-width:184px;background:var(--card);
border:1px solid var(--line);border-radius:10px;box-shadow:0 16px 40px rgba(6,46,60,.16);padding:8px;
opacity:0;visibility:hidden;transition:.2s;margin-top:10px;z-index:70}
.nav-item:hover .dropdown{opacity:1;visibility:visible;margin-top:4px}
.dropdown a{display:block;padding:9px 16px;border-radius:8px;font-size:14px;color:var(--ink);white-space:nowrap}
.dropdown a:hover{background:var(--ice-2);color:var(--ocean)}
.nav-cta{background:var(--ocean);color:#fff;padding:9px 20px;border-radius:8px;font-size:14px;font-weight:700;white-space:nowrap;
box-shadow:0 4px 14px rgba(12,107,138,.28)}
.nav-cta:hover{background:var(--ocean-deep)}

/* sonar hero —— 冰海分屏 + 白鲸 + 声呐 */
.sonar-hero{position:relative;overflow:hidden;padding:0}
.hero-bg{position:absolute;inset:0;background-size:cover;background-position:62% 45%;filter:blur(9px) saturate(1.06);transform:scale(1.08)}
.hero-veil{position:absolute;inset:0;background:linear-gradient(100deg,rgba(234,245,250,.97) 0%,rgba(234,245,250,.84) 42%,rgba(234,245,250,.26) 72%,rgba(6,46,60,.14) 100%)}
.hero-inner{position:relative;display:grid;grid-template-columns:1.05fr .95fr;gap:20px;align-items:center;min-height:600px;padding:72px 24px 96px}
.hero-copy{position:relative;z-index:2}
.eyebrow{display:inline-block;font-size:13px;letter-spacing:3px;color:var(--aurora);font-weight:600;text-transform:uppercase;margin-bottom:14px}
.hero-copy h1{font-family:Georgia,"Songti SC","SimSun",serif;color:var(--ink);margin-bottom:8px}
.hero-copy h1 .accent{color:var(--ocean)}
.hero-tag{font-size:21px;font-weight:700;letter-spacing:4px;color:var(--ocean);margin-bottom:16px}
.hero-sub{font-size:17px;color:var(--ink-soft);max-width:520px}
.hero-actions{display:flex;flex-wrap:wrap;gap:14px;align-items:center;margin:26px 0 22px}
.btn{display:inline-block;padding:13px 28px;border-radius:8px;font-size:15px;font-weight:700;
letter-spacing:.5px;transition:.2s;border:1px solid transparent;cursor:pointer}
.btn-primary{background:var(--ocean);color:#fff;box-shadow:0 6px 20px rgba(12,107,138,.32)}
.btn-primary:hover{background:var(--ocean-deep);transform:translateY(-1px);box-shadow:0 10px 26px rgba(12,107,138,.4)}
.btn-ghost{background:transparent;color:var(--ocean);border:1px solid var(--ocean)}
.btn-ghost:hover{background:rgba(12,107,138,.08)}
.btn-big{padding:16px 44px;font-size:17px}
.hero-points{display:flex;gap:10px;flex-wrap:wrap}
.point{background:rgba(255,255,255,.72);border:1px solid var(--sky-soft);color:var(--ink);
padding:6px 16px;border-radius:8px;font-size:13px}
.hero-media{position:relative;display:flex;align-items:center;justify-content:center;min-height:380px}
.sonar-rings{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;opacity:.85}
.sonar-rings .sonar{width:380px;height:380px;animation:sonar-pulse 4s ease-in-out infinite}
@keyframes sonar-pulse{0%,100%{transform:scale(1);opacity:.85}50%{transform:scale(1.06);opacity:1}}
.sweep-line{position:absolute;left:0;right:0;bottom:0;height:2px;
background:linear-gradient(90deg,transparent,var(--aurora),var(--sky),transparent);opacity:.55}
@media(max-width:900px){
.hero-inner{grid-template-columns:1fr;min-height:0;padding:48px 18px 72px}
.hero-media{min-height:260px}
.sonar-rings .sonar{width:260px;height:260px}
}

/* section */
.section{padding:72px 0}
.section.alt{background:var(--ice-2)}
.section-head{text-align:center;max-width:640px;margin:0 auto 44px}
.section-head .eyebrow{color:var(--aurora)}
.section-head p{color:var(--ink-soft);margin-top:12px}
.section-foot{text-align:center;margin-top:36px}

/* 声呐回响数据带 */
.echo-strip{background:var(--ice-2);border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:38px 0}
.echo-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.echo-cell{text-align:center;padding:12px 8px;position:relative}
.echo-cell::before{content:"";position:absolute;top:-14px;left:50%;transform:translateX(-50%);width:40px;height:40px;
border:1px solid var(--sky);border-radius:50%}
.echo-cell:nth-child(2)::before{border-color:var(--aurora)}
.echo-cell:nth-child(3)::before{border-color:var(--sky-soft)}
.echo-cell:nth-child(4)::before{border-color:var(--gold)}
.echo-cell em{display:block;font-style:normal;font-size:13px;font-weight:700;letter-spacing:2px;color:var(--ocean);margin-bottom:8px}
.echo-cell strong{display:block;font-size:20px;color:var(--ink);margin-bottom:6px}
.echo-cell p{font-size:13px;color:var(--ink-soft)}

/* 深度分层 */
.depth-zones{padding:72px 0}
.depth-list{max-width:760px;margin:0 auto;display:flex;flex-direction:column;gap:0}
.dz-card{display:flex;gap:26px;align-items:flex-start;padding:26px 0;border-bottom:1px solid var(--line);position:relative}
.dz-card:last-child{border-bottom:none}
.dz-meter{flex:0 0 96px;height:96px;border-radius:50%;background:linear-gradient(135deg,var(--sky-soft),var(--ice));
border:2px solid var(--sky);display:flex;align-items:center;justify-content:center;color:var(--ocean);font-weight:800;font-size:18px;letter-spacing:1px}
.dz-card:nth-child(2) .dz-meter{border-color:var(--aurora);background:linear-gradient(135deg,#DFF7F3,var(--ice))}
.dz-card:nth-child(3) .dz-meter{border-color:var(--ocean);background:linear-gradient(135deg,#D3E9F4,var(--ice))}
.dz-body h3{margin-bottom:6px;color:var(--ink)}
.dz-body p{color:var(--ink-soft);font-size:15px}
@media(max-width:640px){.dz-card{flex-direction:column}.dz-meter{flex:0 0 72px;height:72px;width:72px}}

/* 白鲸群节点 */
.whale-pod{position:relative;padding:96px 0;overflow:hidden}
.pod-bg{position:absolute;inset:0;background-size:cover;background-position:center;opacity:.34}
.pod-overlay{position:absolute;inset:0;background:linear-gradient(180deg,var(--ice),rgba(6,46,60,.45),var(--ice))}
.pod-inner{position:relative}
.section-head.light h2{color:#fff}
.section-head.light p{color:rgba(255,255,255,.8)}
.section-head.light .eyebrow{color:var(--sky)}
.podmap{display:block;width:100%;height:auto;max-width:820px;margin:0 auto;filter:drop-shadow(0 0 16px rgba(127,201,232,.35))}
.pod-chips{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-top:28px}
.chip{background:rgba(255,255,255,.14);border:1px solid rgba(127,201,232,.5);color:#fff;
padding:7px 18px;border-radius:8px;font-size:14px;font-weight:600;backdrop-filter:blur(4px)}

/* 洋流对比 */
.current-lanes{max-width:640px;margin:0 auto}
.lane{display:grid;grid-template-columns:180px 1fr 64px;gap:16px;align-items:center;margin-bottom:22px}
.lane-name{font-size:14px;color:var(--ink);font-weight:600}
.lane-track{height:18px;border-radius:9px;background:var(--ice-2);border:1px solid var(--line);overflow:hidden;position:relative}
.lane-flow{height:100%;border-radius:8px;position:relative}
.lane-flow::after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,transparent 30%,rgba(255,255,255,.5),transparent 70%);
animation:flow 2.2s linear infinite}
.lane-flow.slow{background:linear-gradient(90deg,#9BB4BF,#B7C9D1)}
.lane-flow.fast{background:linear-gradient(90deg,var(--ocean),var(--aurora))}
@keyframes flow{0%{transform:translateX(-100%)}100%{transform:translateX(100%)}}
.lane-val{font-size:14px;font-weight:700;text-align:right}
.lane:first-child .lane-val{color:var(--ink-soft)}
.lane:last-child .lane-val{color:var(--ocean)}

/* 场景墙 */
.scene-wall{padding:72px 0;background:var(--ice-2)}
.scene-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.scene-tile{position:relative;border-radius:14px;overflow:hidden;border:1px solid var(--line);background:var(--card);transition:.25s}
.scene-tile:hover{transform:translateY(-5px);border-color:var(--sky);box-shadow:0 16px 34px rgba(6,46,60,.18)}
.scene-tile img{width:100%;height:200px;object-fit:cover;display:block;filter:saturate(1.02)}
.scene-tile figcaption{padding:18px 18px 20px;background:linear-gradient(180deg,var(--card),var(--ice-2))}
.scene-tag{display:inline-block;font-size:12px;letter-spacing:2px;color:var(--ocean);
border:1px solid var(--sky);padding:2px 10px;border-radius:8px;margin-bottom:8px}
.scene-tile strong{display:block;font-size:17px;color:var(--ink);margin-bottom:4px}
.scene-tile p{font-size:13px;color:var(--ink-soft)}

/* 声呐 FAQ */
.sonar-faq{max-width:760px;margin:0 auto}
.sq-item{background:var(--card);border:1px solid var(--line);border-left:3px solid var(--aurora);border-radius:10px;
margin-bottom:12px;overflow:hidden}
.sq-item summary{padding:18px 22px;font-weight:600;cursor:pointer;list-style:none;position:relative;color:var(--ink)}
.sq-item summary::after{content:"+";position:absolute;right:22px;top:14px;font-size:22px;color:var(--aurora);transition:.2s}
.sq-item[open] summary::after{transform:rotate(45deg)}
.sq-item p{padding:0 22px 20px;color:var(--ink-soft);font-size:14px}

/* bento */
.bento{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.people-row{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
@media(max-width:820px){.people-row{grid-template-columns:repeat(2,1fr)}}
.bento-card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:28px 24px;transition:.2s}
.bento-card:hover{transform:translateY(-4px);box-shadow:0 12px 28px rgba(6,46,60,.1);border-color:var(--sky)}
.bento-ico{font-size:30px;margin-bottom:12px}
.bento-card h3{margin-bottom:8px}
.bento-card p{font-size:14px;color:var(--ink-soft)}

/* split */
.split{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.split.rev .split-media{order:-1}
.split-copy .eyebrow{color:var(--aurora)}
.split-copy h2{margin-bottom:16px}
.split-copy h3{margin:18px 0 6px}
.split-copy p{color:var(--ink-soft);margin-bottom:12px}
.checklist{list-style:none;margin:18px 0 22px}
.checklist li{padding:6px 0 6px 28px;position:relative;color:var(--ink)}
.checklist li::before{content:"✓";position:absolute;left:0;color:var(--aurora);font-weight:700}
.media-frame{border-radius:16px;overflow:hidden;box-shadow:0 16px 40px rgba(6,46,60,.16)}
.media-frame img{width:100%;height:320px;object-fit:cover}

/* steps */
.steps{max-width:640px;margin:0 auto;display:flex;flex-direction:column;gap:0}
.step{display:flex;gap:20px;position:relative;padding-bottom:32px}
.step:not(:last-child)::before{content:"";position:absolute;left:21px;top:48px;bottom:0;width:2px;background:var(--line)}
.step-num{flex:0 0 44px;height:44px;border-radius:50%;background:var(--ocean);color:#fff;
display:flex;align-items:center;justify-content:center;font-weight:800;font-size:18px}
.step-body h3{margin-bottom:4px}
.step-body p{color:var(--ink-soft);font-size:14px}

/* platform */
.platform-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.platform-float{background:var(--card);border:1px solid var(--line);border-radius:14px;overflow:hidden;display:block;transition:.2s}
.platform-float:hover{transform:translateY(-4px);box-shadow:0 12px 28px rgba(6,46,60,.12)}
.pf-top{height:6px}
.pf-body{padding:22px 20px}
.pf-ico{font-size:26px}
.pf-body h3{margin:10px 0 4px}
.pf-body p{font-size:13px;color:var(--ink-soft);margin-bottom:12px}
.pf-link{color:var(--ocean);font-size:13px;font-weight:600}

/* table */
.table-wrap{overflow-x:auto;background:var(--card);border:1px solid var(--line);border-radius:14px}
table{width:100%;border-collapse:collapse;font-size:14px;min-width:520px}
th,td{padding:13px 18px;text-align:left;border-bottom:1px solid var(--line)}
thead th{background:var(--ocean);color:#fff;font-weight:600}
tbody tr:last-child td{border-bottom:none}
tbody tr:hover{background:var(--ice-2)}

/* tip/callout */
.tip{background:var(--ice-2);border-left:4px solid var(--aurora);padding:16px 20px;border-radius:8px;
font-size:14px;color:var(--ink);margin-top:20px}

/* page-hero (inner pages) */
.page-hero{background:radial-gradient(ellipse at 50% 0%,rgba(127,201,232,.28),transparent 60%),var(--ice);color:var(--ink);padding:56px 0 60px;text-align:center}
.page-hero .eyebrow{color:var(--aurora)}
.page-hero h1{font-family:Georgia,"Songti SC","SimSun",serif;margin:6px 0 14px}
.page-hero .accent{color:var(--ocean)}
.page-sub{font-size:16px;color:var(--ink-soft);max-width:640px;margin:0 auto}
.page-hero .hero-actions{margin:24px 0 0;justify-content:center}
.page-hero .btn-ghost{color:var(--ocean);border-color:var(--ocean)}
.page-hero .btn-ghost:hover{background:rgba(12,107,138,.08)}

/* breadcrumb */
.breadcrumb{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;font-size:13px;margin-bottom:20px;opacity:.85}
.crumb a{color:var(--ink-soft);border-bottom:1px dotted var(--line)}
.crumb a:hover{color:var(--ocean)}
.crumb+.crumb::before{content:"/";margin-right:8px;opacity:.5}

/* article */
.article-hero{background:radial-gradient(ellipse at 50% 0%,rgba(127,201,232,.28),transparent 60%),var(--ice);background-size:cover;background-position:center;color:var(--ink);padding:56px 0 48px}
.article-hero h1{font-family:Georgia,"Songti SC","SimSun",serif;font-size:clamp(26px,3.6vw,40px);margin:10px 0 14px;max-width:820px}
.article-hero .accent{color:var(--ocean)}
.article-meta{font-size:13px;color:var(--ink-soft)}
.article-layout{display:grid;grid-template-columns:240px 1fr;gap:44px;padding:48px 0 64px;align-items:start}
.toc{position:sticky;top:88px;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:20px}
.toc h4{font-size:13px;color:var(--ink-soft);letter-spacing:1px;margin-bottom:12px}
.toc a{display:block;font-size:13px;color:var(--ink);padding:6px 0;border-left:2px solid transparent;padding-left:12px}
.toc a:hover{color:var(--ocean);border-color:var(--aurora)}
.article-body{max-width:720px}
.article-body h2{font-size:24px;margin:34px 0 14px;padding-left:14px;border-left:4px solid var(--aurora)}
.article-body h3{font-size:18px;margin:26px 0 10px}
.article-body p{margin-bottom:16px;color:var(--ink)}
.article-body ul,.article-body ol{margin:0 0 18px 24px}
.article-body li{margin-bottom:8px}
.article-body img{border-radius:12px;margin:20px 0}
.article-body .lead{font-size:18px;color:var(--ocean);font-weight:500}
.related{border-top:1px solid var(--line);margin-top:40px;padding-top:30px}
.related h3{margin-bottom:16px}
.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.related-card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px;font-size:14px}
.related-card:hover{border-color:var(--sky)}
.related-card span{color:var(--ocean);font-weight:600}

/* search */
.search-box{max-width:520px;margin:26px auto 0;display:flex;gap:10px}
.search-input{flex:1;padding:13px 18px;border-radius:8px;border:1px solid var(--line);background:var(--card);color:var(--ink);font-size:15px;outline:none}
.search-input:focus{border-color:var(--ocean)}
.search-btn{background:var(--ocean);color:#fff;border:none;padding:0 26px;border-radius:8px;font-size:15px;font-weight:700;cursor:pointer}
.search-results{max-width:640px;margin:30px auto 0;text-align:left}
.search-results .hit{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:14px 18px;margin-bottom:10px}
.search-results .hit a{color:var(--ocean);font-weight:600}

/* sitemap page */
.sitegroup{margin-bottom:34px}
.sitegroup h2{font-size:20px;margin-bottom:14px;color:var(--ocean)}
.sitegroup ul{list-style:none;display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.sitegroup li a{color:var(--ink);font-size:14px;border-bottom:1px dotted var(--line);display:inline-block;padding-bottom:2px}
.sitegroup li a:hover{color:var(--ocean)}

/* share */
.share{display:flex;gap:14px;align-items:center;font-size:13px;margin:24px 0 0;color:var(--ink-soft)}
.share a{color:var(--ocean);border-bottom:1px dotted var(--ocean)}

/* deep cta */
.deep-cta{position:relative;overflow:hidden;color:#fff;padding:100px 0}
.cta-bg{position:absolute;inset:0;background-size:cover;background-position:center;filter:blur(6px);transform:scale(1.08)}
.cta-overlay{position:absolute;inset:0;background:linear-gradient(135deg,rgba(6,46,60,.9),rgba(8,70,90,.62))}
.cta-inner{position:relative;display:flex;justify-content:center}
.cta-card{max-width:560px;padding:48px 52px;text-align:center;background:rgba(255,255,255,.1);backdrop-filter:blur(12px);
border:1px solid rgba(127,201,232,.4);border-radius:14px;box-shadow:0 0 40px rgba(18,167,155,.18)}
.cta-fluke{width:64px;margin:0 auto 14px}
.cta-fluke .fluke{width:64px;height:auto}
.cta-card h2{font-family:Georgia,"Songti SC","SimSun",serif;margin-bottom:10px}
.cta-card .accent{color:var(--sky)}
.cta-card p{color:rgba(255,255,255,.85);margin-bottom:26px}
.cta-card .btn-primary{background:var(--ocean);color:#fff}

/* footer */
.sitefoot{background:var(--ocean-dark);color:#A9C6D1;padding:56px 0 30px;font-size:14px;border-top:1px solid var(--line)}
.foot-top{display:flex;align-items:flex-start;justify-content:space-between;gap:30px;flex-wrap:wrap;margin-bottom:30px}
.foot-brand{display:flex;align-items:center;gap:10px;color:#fff}
.foot-brand .brand-name em{color:var(--sky)}
.foot-info{color:#A9C6D1;max-width:260px}
.foot-links{display:flex;gap:20px;flex-wrap:wrap}
.foot-links a{color:#A9C6D1}
.foot-links a:hover{color:var(--sky)}
.foot-copy{border-top:1px solid rgba(255,255,255,.12);padding-top:22px;color:#6E8B96;font-size:13px;text-align:center}

/* backtop */
.backtop{position:fixed;right:22px;bottom:26px;width:44px;height:44px;border-radius:50%;border:none;
background:var(--ocean);color:#fff;font-size:20px;cursor:pointer;display:none;z-index:60;box-shadow:0 6px 18px rgba(0,0,0,.2)}
.backtop:hover{background:var(--ocean-deep)}

@media(max-width:900px){
.nav-links{display:none}
.echo-grid{grid-template-columns:repeat(2,1fr)}
.bento{grid-template-columns:repeat(2,1fr)}
.platform-grid{grid-template-columns:repeat(2,1fr)}
.scene-grid{grid-template-columns:repeat(2,1fr)}
.split,.split.rev{grid-template-columns:1fr;gap:30px}
.split.rev .split-media{order:0}
.article-layout{grid-template-columns:1fr}
.toc{position:static}
.related-grid{grid-template-columns:1fr}
.sitegroup ul{grid-template-columns:1fr}
.lane{grid-template-columns:120px 1fr 56px}
.cta-card{padding:40px 28px}
}