/* ============================================================
   北京宇泰数科 · 企业品牌站样式（全站深色统一版）
   设计语言：深空蓝底贯穿整页 + 电光蓝（贴合 YT 六边形 logo）+ 双语切换
   ============================================================ */
:root{
  --navy:#0b1220; --navy2:#101c33; --navy3:#0e1a30;
  --blue:#2f7cf6; --cyan:#38bdf8;
  --card:#111e38; --card-border:rgba(56,189,248,.16);
  --t-strong:#f1f6fd; --t-body:#c3d2e8; --t-muted:#8fa3bd;
  --grad:linear-gradient(135deg,#2f7cf6,#38bdf8);
}
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{font-family:"PingFang SC","Microsoft YaHei","Segoe UI",sans-serif;background:var(--navy);color:var(--t-body);line-height:1.75;}
a{text-decoration:none;color:inherit;}
img{max-width:100%;vertical-align:middle;}
.container{width:100%;max-width:1680px;margin:0 auto;padding:0 clamp(20px,4vw,72px);}

/* ===== 双语切换机制 ===== */
body.en .zh{display:none !important;}
body:not(.en) .en{display:none !important;}

/* ===== 导航 ===== */
.nav{position:sticky;top:0;z-index:100;background:rgba(11,18,32,.92);backdrop-filter:blur(10px);border-bottom:1px solid rgba(56,189,248,.15);}
.nav-inner{width:100%;max-width:1680px;margin:0 auto;padding:0 clamp(20px,4vw,72px);height:64px;display:flex;align-items:center;justify-content:space-between;gap:12px;}
.brand{display:flex;align-items:center;gap:10px;color:#fff;font-weight:700;font-size:16px;}
.logo-chip{background:#000;border-radius:10px;padding:2px;line-height:0;box-shadow:0 0 14px rgba(47,124,246,.55);}
.logo-chip img{width:38px;height:auto;border-radius:8px;}
.brand .b-name small{display:block;font-size:10.5px;font-weight:400;color:#7dd3fc;letter-spacing:1px;}
.nav-links{display:flex;gap:22px;font-size:13.5px;align-items:center;}
.nav-links a{color:#cbd5e1;transition:color .2s;}
.nav-links a:hover{color:#7dd3fc;}
.lang-btn{background:transparent;border:1px solid rgba(56,189,248,.5);color:#7dd3fc;border-radius:999px;padding:4px 14px;font-size:12.5px;cursor:pointer;transition:.2s;}
.lang-btn:hover{background:rgba(56,189,248,.15);}
@media(max-width:760px){.nav-links a{display:none;}}

/* ===== Hero ===== */
.hero{background:radial-gradient(72% 130% at 78% -20%,rgba(47,124,246,.38),transparent 62%),linear-gradient(160deg,#0b1220 0%,#0d1f3d 55%,#123059 100%);color:#fff;padding:clamp(64px,8vw,110px) 0 clamp(56px,7vw,96px);position:relative;overflow:hidden;}
.hero::before{content:"";position:absolute;inset:0;background-image:linear-gradient(rgba(56,189,248,.05) 1px,transparent 1px),linear-gradient(90deg,rgba(56,189,248,.05) 1px,transparent 1px);background-size:44px 44px;pointer-events:none;}
.hero-grid{display:flex;align-items:center;gap:48px;position:relative;}
.hero-text{flex:1;min-width:280px;}
.hero-logo{flex-shrink:0;text-align:center;}
.hero-logo img{width:clamp(140px,10vw,190px);border-radius:26px;box-shadow:0 0 70px rgba(47,124,246,.65);}
.hero .kicker{font-size:12.5px;letter-spacing:4px;color:#7dd3fc;text-transform:uppercase;margin-bottom:16px;}
.hero h1{font-size:clamp(30px,3.2vw,46px);line-height:1.3;margin-bottom:14px;}
.hero h1 .grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;}
.hero p.sub{font-size:16px;color:#b6c4d8;max-width:620px;margin-bottom:26px;}
.hero .chips{display:flex;flex-wrap:wrap;gap:10px;}
.chip{border:1px solid rgba(125,211,252,.35);color:#bae6fd;border-radius:999px;padding:5px 16px;font-size:13px;background:rgba(56,189,248,.08);}
@media(max-width:820px){.hero-grid{flex-direction:column;text-align:center;}.hero .chips{justify-content:center;}.hero p.sub{margin:0 auto 26px;}}

/* ===== 数据带 ===== */
.stats{background:var(--navy3);border-top:1px solid rgba(56,189,248,.12);border-bottom:1px solid rgba(56,189,248,.12);padding:34px 0;}
.stats .grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;}
.stat{text-align:center;}
.stat .num{font-size:30px;font-weight:800;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;}
.stat .num small{font-size:15px;}
.stat .lab{font-size:12.5px;color:#8fa3bd;margin-top:2px;}
@media(max-width:760px){.stats .grid{grid-template-columns:repeat(2,1fr);}}

/* ===== 区块（全站统一深色底） ===== */
.section{padding:72px 0;background:var(--navy);color:var(--t-body);}
.sec-head{margin-bottom:40px;text-align:center;}
.sec-head .tag-line{font-size:12.5px;color:#5ea0f8;font-weight:700;letter-spacing:3px;margin-bottom:8px;}
.sec-head h2{font-size:clamp(22px,2.1vw,30px);color:#fff;}
.sec-head p{color:var(--t-muted);font-size:14.5px;margin-top:8px;max-width:680px;margin-left:auto;margin-right:auto;}
.section.dark{background:linear-gradient(180deg,#0d1f3d 0%,#0b1220 100%);}
.section.dark .sec-head h2{color:#fff;}
.section.dark .sec-head p{color:#8fa3bd;}

/* ===== 产品卡片（深蓝玻璃质感） ===== */
.p-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px;}
@media(max-width:860px){.p-grid{grid-template-columns:1fr;}}
.p-card{background:linear-gradient(165deg,#132341 0%,#101c33 60%,#0e1930 100%);border:1px solid var(--card-border);border-radius:16px;padding:30px 32px;transition:.25s;position:relative;overflow:hidden;}
.p-card::before{content:"";position:absolute;top:0;left:0;right:0;height:3px;background:var(--grad);}
.p-card::after{content:"";position:absolute;top:-60px;right:-60px;width:180px;height:180px;background:radial-gradient(circle,rgba(56,189,248,.12),transparent 70%);pointer-events:none;}
.p-card:hover{box-shadow:0 14px 40px rgba(2,10,30,.6);border-color:rgba(56,189,248,.4);transform:translateY(-3px);}
.p-card .p-head{display:flex;align-items:center;gap:14px;margin-bottom:14px;}
.p-abbr{width:54px;height:54px;border-radius:14px;background:linear-gradient(135deg,#123059,#2f7cf6);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:14px;flex-shrink:0;box-shadow:0 6px 16px rgba(47,124,246,.35);}
.p-card h3{font-size:18px;color:#fff;}
.p-card .p-en{font-size:11.5px;color:var(--t-muted);letter-spacing:.5px;}
.p-card p.desc{font-size:14px;color:var(--t-body);margin-bottom:14px;}
.p-feats{display:grid;grid-template-columns:1fr 1fr;gap:6px 14px;margin-bottom:0;}
.p-feats li{list-style:none;font-size:12.8px;color:#a9bad3;padding-left:20px;position:relative;}
.p-feats li::before{content:"";position:absolute;left:2px;top:9px;width:8px;height:8px;border-radius:2px;background:var(--grad);transform:rotate(45deg);}
.p-tag{position:absolute;top:16px;right:-34px;background:var(--grad);color:#fff;font-size:11px;font-weight:700;padding:4px 40px;transform:rotate(38deg);letter-spacing:1px;}

/* ===== 小工具矩阵 ===== */
.tool-cats{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-bottom:26px;}
@media(max-width:860px){.tool-cats{grid-template-columns:repeat(2,1fr);}}
.tool-cat{background:#101c33;border:1px solid rgba(56,189,248,.18);border-radius:14px;padding:20px;text-align:center;transition:.2s;}
.tool-cat:hover{border-color:rgba(56,189,248,.5);transform:translateY(-2px);}
.tool-cat .t-ico{font-size:24px;color:#38bdf8;font-weight:800;margin-bottom:6px;}
.tool-cat h4{font-size:14.5px;color:#e6edf7;margin-bottom:4px;}
.tool-cat p{font-size:12px;color:#8fa3bd;}
.tool-tags{display:flex;flex-wrap:wrap;gap:9px;justify-content:center;}
.tool-tags span{border:1px solid rgba(125,211,252,.3);color:#9fc9f5;font-size:12px;border-radius:999px;padding:4px 14px;background:rgba(56,189,248,.06);}

/* ===== 优势（深色卡） ===== */
.adv-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;}
@media(max-width:860px){.adv-grid{grid-template-columns:repeat(2,1fr);}}
.adv{background:linear-gradient(165deg,#132341 0%,#101c33 100%);border:1px solid var(--card-border);border-radius:14px;padding:24px 22px;transition:.2s;}
.adv:hover{border-color:rgba(56,189,248,.4);transform:translateY(-2px);}
.adv .a-ico{width:44px;height:44px;border-radius:12px;background:rgba(47,124,246,.16);color:#5ec2fb;display:flex;align-items:center;justify-content:center;font-size:19px;font-weight:800;margin-bottom:12px;border:1px solid rgba(56,189,248,.25);}
.adv h4{font-size:15px;margin-bottom:6px;color:#fff;}
.adv p{font-size:12.8px;color:var(--t-muted);}

/* ===== 集成生态 ===== */
.eco{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;}
.eco span{background:#101c33;border:1px solid var(--card-border);border-radius:10px;padding:8px 20px;font-size:13px;font-weight:600;color:#9fc9f5;}

/* ===== 关于/联系 ===== */
.about-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:26px;align-items:stretch;}
@media(max-width:860px){.about-grid{grid-template-columns:1fr;}}
.about-box{background:linear-gradient(165deg,#132341 0%,#101c33 100%);border:1px solid var(--card-border);border-radius:16px;padding:30px 32px;}
.about-box h3{font-size:16.5px;margin-bottom:10px;color:#fff;}
.about-box p{font-size:13.8px;color:var(--t-body);margin-bottom:10px;}
.c-row{display:flex;gap:12px;align-items:center;padding:11px 0;border-bottom:1px dashed rgba(56,189,248,.18);font-size:14px;}
.c-row:last-child{border-bottom:none;}
.c-row .c-k{color:var(--t-muted);min-width:80px;}
.c-row .c-v{color:#7dd3fc;font-weight:600;word-break:break-all;}

/* ===== 页脚 ===== */
.footer{background:var(--navy);border-top:1px solid rgba(56,189,248,.12);color:#8fa3bd;padding:30px 0;font-size:12.5px;}
.footer .container{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px;}
.footer .f-brand{display:flex;align-items:center;gap:10px;color:#cbd5e1;}
.footer .logo-chip img{width:30px;}
.footer a{color:#7dd3fc;}

/* ===== 入场动画 ===== */
.reveal{opacity:0;transform:translateY(22px);transition:opacity .6s ease,transform .6s ease;}
.reveal.on{opacity:1;transform:none;}