/* ============================
   H&F Boiler - Stylesheet
   不使用 position:fixed 容器
   内容永远在正常文档流中
   ============================ */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;overflow-x:hidden;}
body{
    font-family:Arial,Helvetica,sans-serif;
    background:#f8fafc;
    color:#0f172a;
    line-height:1.6;
}
a{color:#0891b2;text-decoration:none;}

/* Header */
.site-header{
    position:fixed;top:0;left:0;right:0;height:72px;z-index:100;
    padding:0 40px;display:flex;align-items:center;justify-content:space-between;
    background:#0f172a;backdrop-filter:blur(12px);
    box-shadow:0 1px 0 rgba(0,0,0,0.1);
}
.logo{font-size:22px;font-weight:800;letter-spacing:-0.5px;color:#ffffff;display:inline-flex;align-items:center;gap:8px;}
.logo img{height:36px;width:auto;border-radius:4px;}
.logo span{color:#06b6d4;}
.nav{display:flex;gap:24px;list-style:none;align-items:center;margin:0;padding:0;}
.nav>li>a{color:#cbd5e1;font-size:14px;font-weight:500;transition:color 0.3s;padding:8px 0;position:relative;}
.nav>li>a::after{content:'';position:absolute;bottom:0;left:0;width:0;height:2px;background:#0891b2;transition:width 0.3s;}
.nav>li>a:hover{color:#ffffff;}
.nav>li>a:hover::after{width:100%;}
.nav-cta{background:#0891b2;color:#fff!important;padding:8px 20px!important;border-radius:6px;font-weight:600;}
.nav-cta::after{display:none!important;}

/* Dropdown */
.nd{position:relative;}
.nd>a{display:flex;align-items:center;gap:4px;cursor:pointer;}
.da{font-size:10px;transition:transform 0.3s;}
.nd:hover .da{transform:rotate(180deg);}
.dm{position:absolute;top:100%;left:50%;transform:translateX(-50%) translateY(4px);padding-top:12px;min-width:250px;opacity:0;pointer-events:none;transition:opacity 0.25s,transform 0.25s;}
.dm::before{content:'';position:absolute;top:0;left:-10px;right:-10px;height:12px;background:transparent;}
.nd:hover .dm,.dm:hover,.nd.show .dm{opacity:1;pointer-events:all;transform:translateX(-50%) translateY(0);}
.di{background:rgba(15,23,42,0.98);backdrop-filter:blur(16px);border:1px solid #334155;border-radius:12px;padding:6px;box-shadow:0 16px 48px rgba(0,0,0,0.3);}
.di a{display:flex;align-items:center;gap:12px;padding:10px 14px;border-radius:8px;color:#cbd5e1;text-decoration:none;font-size:13px;transition:background 0.2s;}
.di a:hover{background:rgba(6,182,212,0.15);color:#ffffff;}
.di-icon{font-size:16px;width:24px;text-align:center;}
.dl{font-weight:600;font-size:13px;color:#ffffff;}
.dd{font-size:11px;color:#64748b;}

/* Sections */
.sec{padding:120px 40px;max-width:1200px;margin:0 auto;position:relative;z-index:1;overflow-x:clip;}
.sl{font-size:12px;font-weight:600;letter-spacing:3px;text-transform:uppercase;color:#0891b2;margin-bottom:12px;}
.st{font-size:40px;font-weight:700;letter-spacing:-1px;line-height:1.15;margin-bottom:20px;}
.sd{font-size:17px;color:#475569;max-width:640px;line-height:1.7;}
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 32px;border-radius:8px;font-size:15px;font-weight:600;text-decoration:none;border:none;cursor:pointer;transition:transform 0.2s,box-shadow 0.2s;font-family:Arial,Helvetica,sans-serif;}
.btn:hover{transform:translateY(-2px);}
.bp{background:#0891b2;color:#ffffff;box-shadow:0 4px 24px rgba(8,145,178,0.25);}
.bs{background:transparent;color:#0f172a;border:1px solid #cbd5e1;}
.bs:hover{border-color:#0891b2;box-shadow:0 0 20px rgba(8,145,178,0.1);}

/* Hero */
.hero{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:flex-start;padding:120px 20px 40px;text-align:center;overflow-x:clip;overflow-y:visible;position:relative;z-index:1;}
.hc{padding-top:20px;}
@keyframes gm{0%{transform:translate(0,0);}100%{transform:translate(30px,30px);}}
/* 网格背景 - fixed 覆盖全页面 */
body::before{content:'';position:fixed;top:0;left:0;width:100%;height:100%;background-image:linear-gradient(rgba(8,145,178,0.08) 1px,transparent 1px),linear-gradient(90deg,rgba(8,145,178,0.08) 1px,transparent 1px);background-size:60px 60px;animation:gm 24s linear infinite;pointer-events:none;z-index:0;}
.hglow{position:absolute;width:600px;height:600px;border-radius:50%;background:radial-gradient(circle,rgba(8,145,178,0.06) 0%,transparent 70%);top:50%;left:50%;transform:translate(-50%,-50%);pointer-events:none;}
.hc{position:relative;z-index:1;width:100%;max-width:100%;padding:0 30px;}
.hero h1{font-size:60px;font-weight:800;letter-spacing:-2px;line-height:1.08;margin-bottom:24px;max-width:900px;margin-left:auto;margin-right:auto;}
.hero h1 .hl{background:linear-gradient(135deg,#0284c7,#0891b2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;}
.hero .hsub{font-size:20px;color:#475569;margin-bottom:36px;max-width:700px;margin-left:auto;margin-right:auto;line-height:1.7;}
.bw{display:flex;flex-wrap:wrap;gap:20px;justify-content:center;margin-bottom:44px;}
.bw span{display:flex;align-items:center;gap:8px;font-size:14px;color:#475569;}
.bw .ck{display:inline-flex;width:20px;height:20px;border-radius:50%;background:rgba(8,145,178,0.12);align-items:center;justify-content:center;font-size:10px;color:#0891b2;}
.ha{display:flex;gap:16px;justify-content:center;flex-wrap:wrap;}

/* Carousel */
.carousel-wrap{width:65%;max-width:2000px;margin:20px auto;position:relative;padding:0;}
.carousel-track{position:relative;overflow:hidden;border-radius:12px;aspect-ratio:21/9;}
.carousel-slide{position:absolute;top:0;left:0;width:100%;height:100%;opacity:0;transition:opacity 0.8s cubic-bezier(0.4,0,0.2,1);pointer-events:none;}
.carousel-slide.active{opacity:1;pointer-events:all;}
.carousel-slide .slide-bg{width:100%;height:100%;display:flex;align-items:center;justify-content:center;flex-direction:column;gap:12px;position:relative;}
.carousel-slide .slide-bg::before{content:'';position:absolute;inset:0;border-radius:16px;border:1px solid #e2e8f0;}
.carousel-icon{font-size:72px;position:relative;z-index:1;opacity:0.3;}
.carousel-label{font-size:16px;font-weight:600;color:#475569;position:relative;z-index:1;letter-spacing:0.5px;}
.carousel-spec{font-size:13px;color:#94a3b8;position:relative;z-index:1;}
.carousel-dots{display:flex;justify-content:center;gap:10px;margin-top:16px;}
.carousel-dots .dot{width:8px;height:8px;border-radius:50%;background:#0f172a;border:none;cursor:pointer;transition:all 0.3s;padding:0;}
.carousel-dots .dot.active{background:#0891b2;width:24px;border-radius:4px;}
.carousel-dots .dot:hover{background:#94a3b8;}

/* About */
.ag{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;}
.ai{aspect-ratio:4/3;border-radius:16px;border:1px solid #e2e8f0;display:flex;align-items:center;justify-content:center;background:rgba(0,0,0,0.03);font-size:48px;color:rgba(0,0,0,0.05);overflow:hidden;}
.apc .ai{font-size:28px;margin-bottom:10px;}
.sg{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:32px;}
.sc{padding:20px;background:#ffffff;border:1px solid #e2e8f0;border-radius:12px;}
.sc .n{font-size:30px;font-weight:800;color:#0891b2;line-height:1;}
.sc .l{font-size:13px;color:#94a3b8;margin-top:4px;}
.pn{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin-bottom:64px;}
.pn a{padding:10px 20px;border-radius:8px;border:1px solid #e2e8f0;color:#475569;text-decoration:none;font-size:14px;font-weight:500;transition:all 0.3s;}
.pn a:hover{border-color:#0891b2;color:#0f172a;background:rgba(8,145,178,0.08);}

/* Product Detail */
.pd{padding:100px 0;border-top:1px solid #e2e8f0;max-width:1100px;margin:0 auto;}
.pd:first-of-type{border-top:none;padding-top:0;}
.pdh{display:grid;grid-template-columns:1fr 1fr;gap:50px;align-items:center;margin-bottom:50px;}
.pdh h2{font-size:38px;font-weight:800;letter-spacing:-1px;line-height:1.1;margin-bottom:12px;}
.pdh h2 sp{background:linear-gradient(135deg,#0891b2,#06b6d4);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;}
.pdh .pds{font-size:15px;color:#475569;line-height:1.7;margin-bottom:20px;max-width:100%;}
.pbw{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:16px;}
.pb{padding:4px 12px;background:rgba(8,145,178,0.1);border-radius:16px;font-size:12px;color:#0891b2;font-weight:500;}
.pim{aspect-ratio:4/3;border-radius:14px;border:1px solid #e2e8f0;display:flex;align-items:center;justify-content:center;background:rgba(0,0,0,0.03);font-size:64px;color:rgba(0,0,0,0.1);}
.prg{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:12px;margin-bottom:50px;}
.prc{padding:20px;background:#ffffff;border:1px solid #e2e8f0;border-radius:12px;text-align:center;}
.prc .v{font-size:22px;font-weight:800;color:#0891b2;line-height:1;}
.prc .l{font-size:12px;color:#94a3b8;margin-top:6px;}
.pfg{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-bottom:50px;}
.pfi{display:flex;gap:14px;padding:18px;background:#ffffff;border:1px solid #e2e8f0;border-radius:12px;}
.pfi .fi{font-size:20px;flex-shrink:0;width:36px;height:36px;display:flex;align-items:center;justify-content:center;background:rgba(8,145,178,0.1);border-radius:8px;}
.pfi .ft h4{font-size:14px;font-weight:600;margin-bottom:2px;}
.pfi .ft p{font-size:13px;color:#475569;line-height:1.5;}
.pt{margin-bottom:50px;}
.pt h3,.pa h3{font-size:16px;font-weight:600;margin-bottom:16px;}
.pt table{width:100%;border-collapse:collapse;}
.pt tr{border-bottom:1px solid #f1f5f9;}
.pt td{padding:12px 14px;font-size:13px;}
.pt td:first-child{color:#475569;width:42%;}
.pa .appg{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;}
.pa .apc{padding:24px 16px;background:#ffffff;border:1px solid #e2e8f0;border-radius:12px;text-align:center;}
.pa .apc .ai{font-size:28px;margin-bottom:10px;}
.pa .apc h4{font-size:14px;font-weight:600;margin-bottom:4px;}
.pa .apc p{font-size:12px;color:#475569;}

/* Services */
.sv{text-align:center;}
.sg3{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;text-align:left;}
.svc{padding:36px 28px;background:#ffffff;border:1px solid #e2e8f0;border-radius:16px;text-align:center;transition:transform 0.4s,border-color 0.4s;}
.svc:hover{transform:translateY(-6px);border-color:#0891b2;}
.svc .si{width:52px;height:52px;border-radius:14px;background:rgba(8,145,178,0.1);display:flex;align-items:center;justify-content:center;font-size:26px;margin:0 auto 18px;}
.svc h3{font-size:17px;font-weight:600;margin-bottom:10px;}
.svc p{font-size:14px;color:#475569;line-height:1.6;}

/* Features */
.fe{text-align:center;}
.fg{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px;text-align:left;}
.fc{padding:32px 24px;background:#ffffff;border:1px solid #e2e8f0;border-radius:14px;transition:transform 0.4s,border-color 0.4s;}
.fc:hover{transform:translateY(-4px);border-color:#f59e0b;}
.fc .fic{width:44px;height:44px;border-radius:10px;background:rgba(8,145,178,0.1);display:flex;align-items:center;justify-content:center;font-size:20px;margin-bottom:16px;}
.fc h3{font-size:17px;font-weight:600;margin-bottom:8px;}
.fc p{font-size:14px;color:#475569;line-height:1.6;}

/* FAQ */
.fq{max-width:800px;}
.fl{margin-top:40px;display:flex;flex-direction:column;gap:6px;}
.fi{border:1px solid #e2e8f0;border-radius:10px;overflow:hidden;background:#ffffff;transition:border-color 0.3s;}
.fi[open]{border-color:#0891b2;}
.fi summary{padding:18px 22px;font-size:15px;font-weight:500;cursor:pointer;display:flex;justify-content:space-between;align-items:center;list-style:none;}
.fi summary::-webkit-details-marker{display:none;}
.fi summary::after{content:'+';font-size:18px;color:#0891b2;transition:transform 0.3s;flex-shrink:0;margin-left:16px;}
.fi[open] summary::after{transform:rotate(45deg);}
.fi .fa{padding:0 22px 18px;font-size:14px;color:#475569;line-height:1.6;}

/* Contact */
.cg{display:grid;grid-template-columns:1fr 1fr;gap:60px;}
.cf{display:flex;flex-direction:column;gap:14px;}
.cf input,.cf textarea{padding:14px 16px;background:#ffffff;border:1px solid #e2e8f0;border-radius:8px;color:#0f172a;font-family:Arial,Helvetica,sans-serif;font-size:14px;transition:border-color 0.3s;}
.cf input:focus,.cf textarea:focus{outline:none;border-color:#0891b2;box-shadow:0 0 0 3px rgba(8,145,178,0.1);}
.cf textarea{min-height:110px;resize:vertical;}
.ci{display:flex;flex-direction:column;gap:18px;justify-content:center;}
.cii{display:flex;gap:14px;align-items:flex-start;}
.cii .ci-icon{width:38px;height:38px;border-radius:10px;background:rgba(8,145,178,0.1);display:flex;align-items:center;justify-content:center;flex-shrink:0;font-size:16px;}
.cii .cil{font-size:12px;color:#94a3b8;text-transform:uppercase;letter-spacing:1px;}
.cii .civ{font-size:15px;}

/* Footer */
.lang-switcher .di a{font-size:13px;justify-content:flex-start;}
.lang-drop{min-width:160px;}
/* RTL 支持 */
html[dir="rtl"] .nav>li>a::after{left:auto;right:0;}
html[dir="rtl"] .da{margin-left:0;margin-right:2px;}
html[dir="rtl"] .pdh{direction:rtl;}
html[dir="rtl"] .ha{direction:rtl;}
html[dir="rtl"] .ag{direction:rtl;}
html[dir="rtl"] .cg{direction:rtl;}

footer{border-top:1px solid #e2e8f0;padding:36px 40px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:16px;max-width:1200px;margin:0 auto;}
footer p{font-size:13px;color:#94a3b8;}
.flk{display:flex;gap:20px;}
.flk a{font-size:13px;color:#475569;transition:color 0.3s;}
.flk a:hover{color:#0891b2;}

/* Chatbot */
#ai{position:fixed;bottom:28px;right:28px;z-index:1000;display:flex;flex-direction:column;align-items:flex-end;gap:12px;}
#ctb{width:56px;height:56px;border-radius:50%;border:none;background:#0891b2;color:#000;font-size:22px;cursor:pointer;box-shadow:0 0 20px rgba(8,145,178,0.25),0 4px 16px rgba(0,0,0,0.08);transition:transform 0.25s;position:relative;font-family:Arial,Helvetica,sans-serif;}
#ctb:hover{transform:scale(1.08);box-shadow:0 0 36px rgba(8,145,178,0.25),0 6px 24px rgba(0,0,0,0.4);}
#ctb::before{content:'';position:absolute;inset:-3px;border-radius:50%;border:2px solid #0891b2;animation:pr 2s cubic-bezier(0.4,0,0.6,1) infinite;pointer-events:none;}
@keyframes pr{0%{transform:scale(1);opacity:1;}100%{transform:scale(1.35);opacity:0;}}
#cp{width:350px;max-height:500px;background:#ffffff;border:1px solid #e2e8f0;border-radius:14px;overflow:hidden;display:flex;flex-direction:column;box-shadow:0 20px 60px rgba(0,0,0,0.08);position:absolute;bottom:68px;right:0;transform-origin:bottom right;transform:translateX(80px) scale(0.92);opacity:0;pointer-events:none;transition:transform 0.35s cubic-bezier(0.22,1,0.36,1),opacity 0.3s ease;}
#cp.op{transform:translateX(0) scale(1);opacity:1;pointer-events:all;}
.chs{display:flex;justify-content:space-between;align-items:center;padding:14px 18px;border-bottom:1px solid #e2e8f0;}
.chs h3{font-size:14px;font-weight:600;display:flex;align-items:center;gap:8px;}
.chs h3 .dot{width:7px;height:7px;border-radius:50%;background:#22c55e;animation:pd 2s infinite;}
@keyframes pd{0%,100%{opacity:1;}50%{opacity:0.4;}}
#ccl{width:28px;height:28px;border-radius:6px;border:none;background:transparent;color:#94a3b8;font-size:18px;cursor:pointer;transition:background 0.2s;}
.cm{flex:1;padding:16px;overflow-y:auto;display:flex;flex-direction:column;gap:10px;min-height:180px;max-height:300px;}
.cmsg{max-width:85%;padding:10px 14px;border-radius:10px;font-size:13px;line-height:1.5;}
.cmsg.bot{background:#f1f5f9;align-self:flex-start;color:#475569;border-bottom-left-radius:3px;}
.cmsg.user{background:#0891b2;color:#000;align-self:flex-end;border-bottom-right-radius:3px;}
.cia{display:flex;gap:8px;padding:10px 14px;border-top:1px solid #e2e8f0;}
.cia input{flex:1;padding:9px 12px;background:#f1f5f9;border:1px solid #e2e8f0;border-radius:8px;color:#0f172a;font-family:Arial,Helvetica,sans-serif;font-size:13px;}
.cia input:focus{outline:none;border-color:#0891b2;}
#csd{padding:9px 16px;background:#0891b2;color:#000;border:none;border-radius:8px;font-weight:600;font-size:13px;cursor:pointer;font-family:Arial,Helvetica,sans-serif;transition:background 0.2s;}
#csd:hover{background:#06b6d4;}

/* Reveal Animations - 使用 IntersectionObserver */
.rv{opacity:0;transform:translateY(50px);transition:opacity 0.7s cubic-bezier(0.19,1,0.22,1),transform 0.7s cubic-bezier(0.19,1,0.22,1);}
.rl{transform:translateX(-80px);}
.rr{transform:translateX(80px);}
.rv.in{opacity:1;transform:translateX(0) translateY(0);}
.d1{transition-delay:0.04s;}.d2{transition-delay:0.08s;}.d3{transition-delay:0.12s;}
.d4{transition-delay:0.16s;}.d5{transition-delay:0.2s;}.d6{transition-delay:0.24s;}

/* Hamburger */
.hm{display:none;background:none;border:none;color:#fff;font-size:26px;cursor:pointer;padding:0;line-height:1;font-family:Arial;}
.mob-btns{display:none;align-items:center;gap:0;}
.md,.mlg{display:flex;position:fixed;top:76px;right:16px;background:#0f172a;z-index:100;flex-direction:column;padding:8px;border-radius:12px;min-width:200px;box-shadow:0 16px 48px rgba(0,0,0,0.3);border:1px solid #334155;transform:translateX(120%) scale(0.95);opacity:0;pointer-events:none;transition:transform 0.4s cubic-bezier(0.22,1,0.36,1),opacity 0.3s ease;}
.md.op,.mlg.op{transform:translateX(0) scale(1);opacity:1;pointer-events:all;}
.md a,.mlg a{color:#cbd5e1;font-size:14px;padding:10px 16px;border-radius:6px;text-decoration:none;white-space:nowrap;}
.md a:hover,.mlg a:hover{background:rgba(255,255,255,0.08);color:#fff;}

@media(max-width:768px){
.sec{padding:50px 16px;}
.site-header{padding:0 16px;}
.nav{display:none;}
.hm{display:inline-flex;}
.mob-btns{display:flex;}
.ml{display:flex;}
.ag,.cg{grid-template-columns:1fr;gap:30px;}
.pdh{grid-template-columns:1fr;gap:20px;}
.pfg,.pa .appg,.sg3{grid-template-columns:1fr;}
.prg{grid-template-columns:repeat(auto-fit,minmax(140px,1fr));}
.pd{padding:40px 0;}
.sg{grid-template-columns:1fr 1fr;}
#cp{width:calc(100vw - 32px);max-height:45vh;}
#ai{bottom:72px;right:10px;}
#cp{width:calc(100vw - 32px);max-height:40vh;bottom:60px;}
.cm{max-height:20vh;min-height:80px;}
.hero h1{font-size:28px;letter-spacing:-1px;}
.hero{padding:100px 16px 20px;min-height:auto;}
.st{font-size:24px;}
.sd{font-size:15px;}
.pdh h2{font-size:22px;}
.pdh .pds{font-size:13px;}
.pt td{padding:8px 10px;font-size:12px;}
.pfi{padding:14px;}
.pfi .ft p{font-size:12px;}
.apc{padding:16px 12px;}
.carousel-wrap{margin:10px auto;}
.carousel-label{font-size:13px;}
.carousel-spec{font-size:11px;}
.carousel-icon{font-size:48px;}
.svc{padding:24px 16px;}
.svc p{font-size:13px;}
.fc{padding:24px 16px;}
.fc p{font-size:13px;}
.fi summary{font-size:14px;padding:14px 16px;}
.fi .fa{font-size:13px;}
.cf input,.cf textarea{padding:12px 14px;font-size:13px;}
footer{padding:24px 16px;flex-direction:column;text-align:center;}
}
@media(max-width:480px){
.prg{grid-template-columns:1fr;}
.sg{grid-template-columns:1fr;}
.pdh h2{font-size:20px;}
.pb{padding:3px 10px;font-size:11px;}
.pbw{gap:6px;}
}