:root{--ink:#1B2733;--muted:#63707D;--blue:#0E4C8A;--deep:#0A3A6B;--accent:#D9542B;--warm:#F7F5F1;--line:#E5E8EC;--white:#fff}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;color:var(--ink);background:var(--white);line-height:1.75;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{max-width:1120px;margin:0 auto;padding:0 24px}
.sec{padding:88px 0}
.sec.alt{background:var(--warm)}
.eyebrow{color:var(--accent);font-size:13px;letter-spacing:2px;font-weight:600;margin:0 0 12px}
h1,h2,h3,h4{line-height:1.35;margin:0;font-weight:650}
h2{font-size:clamp(26px,3.4vw,38px);letter-spacing:-.5px}
h3{font-size:19px}
.lead{font-size:17px;color:var(--muted);line-height:1.9;margin:18px 0 0}
.sec-head{max-width:760px;margin-bottom:44px}
.mt{display:block;margin-top:10px}
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.96);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;gap:28px;height:72px}
img.nav-logo{height:40px;width:auto;flex-shrink:0}
.nav-links{display:flex;gap:26px;margin-left:auto;align-items:center;min-width:0;flex:0 1 auto;overflow-x:auto;scrollbar-width:none}
.nav-links::-webkit-scrollbar{display:none}
.nav-links a{flex-shrink:0}
.nav-links a{font-size:14px;color:#41505E;white-space:nowrap;transition:color .2s}
.nav-links a:hover,.nav-links a.on{color:var(--blue)}
.nav-links a.on{font-weight:650}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 24px;border-radius:999px;font-size:15px;font-weight:500;letter-spacing:.5px;white-space:nowrap;transition:transform .2s,background .2s,box-shadow .2s;border:1px solid transparent}
.btn:hover{transform:translateY(-2px)}
.btn-p{background:var(--blue);color:#fff;box-shadow:0 6px 18px rgba(14,76,138,.18)}
.btn-p:hover{background:var(--deep)}
.btn-o{border-color:var(--line);color:var(--ink);background:#fff}
.btn-o:hover{border-color:var(--blue);color:var(--blue)}
.btn-nav{padding:9px 20px;background:var(--accent);color:#fff}
.btn-nav:hover{background:#BE4522}
.btn-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:30px}
.hero{padding:76px 0 64px;background:linear-gradient(180deg,#fff 0%,#FBFAF8 100%)}
.hero-grid{display:grid;grid-template-columns:1.08fr .92fr;gap:64px;align-items:center}
.hero h1{font-size:clamp(32px,4.6vw,54px);letter-spacing:-1.5px;margin:0}
.hero h1 em{font-style:normal;color:var(--blue)}
.hero .lead{font-size:18px;max-width:520px}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-top:38px}
.stat b{display:block;font-size:22px;color:var(--blue);line-height:1.3;white-space:nowrap}
.stat span{font-size:12px;color:var(--muted);line-height:1.5;display:block;margin-top:4px}
.portrait{position:relative}
.portrait::before{content:"";position:absolute;left:-18px;top:26px;width:100%;height:100%;border-radius:22px;background:#E9EFF6;z-index:0}
.portrait img{position:relative;z-index:1;width:100%;border-radius:20px;box-shadow:0 20px 50px rgba(20,40,70,.12)}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.grid2{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
.grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:28px;transition:transform .2s,box-shadow .2s,border-color .2s}
.card:hover{transform:translateY(-3px);box-shadow:0 12px 30px rgba(20,40,70,.07);border-color:#D3DEEA}
.card p{color:var(--muted);font-size:14px;margin:10px 0 0}
.num{font-size:13px;font-weight:700;color:var(--accent);letter-spacing:1px}
.quote{border-left:3px solid var(--accent);padding:6px 0 6px 22px;margin:26px 0;font-size:clamp(18px,2.2vw,24px);line-height:1.8;color:var(--deep);font-weight:600}
.stage{background:#fff;border:1px solid var(--line);border-radius:18px;padding:32px;position:relative;overflow:hidden}
.stage::after{content:"";position:absolute;right:-30px;bottom:-40px;width:120px;height:120px;border-radius:50%;background:#F0F5FA}
.stage .tag{display:inline-block;font-size:12px;color:var(--blue);background:#EAF2FA;padding:4px 12px;border-radius:999px}
.stage h3{margin-top:16px;font-size:22px}
.stage p{color:var(--muted);font-size:14px;position:relative;z-index:1}
.layer{text-align:center;padding:26px 16px;border-radius:14px;background:var(--warm);position:relative}
.layer b{display:block;font-size:17px;margin-bottom:6px}
.layer span{font-size:12px;color:var(--muted)}
.layer i{display:block;font-style:normal;font-size:11px;color:var(--blue);margin-top:8px}
.course-row{display:grid;grid-template-columns:56px 1fr 92px 1.5fr;gap:16px;align-items:center;padding:16px 18px;border-bottom:1px solid var(--line);font-size:14px}
.course-row:last-child{border-bottom:0}
.course-row .cn{font-size:20px;font-weight:700;color:#C8D4E0}
.course-row .ct{font-weight:600}
.course-row .cb{font-size:12px;color:var(--blue);background:#EAF2FA;padding:3px 10px;border-radius:999px;text-align:center;justify-self:start}
.course-row .cd{color:var(--muted);font-size:13px}
.course-list{background:#fff;border:1px solid var(--line);border-radius:18px;overflow:hidden}
.concept{padding:20px 22px;background:var(--warm);border-radius:12px}
.concept b{color:var(--deep);font-size:15px}
.concept p{margin:6px 0 0;font-size:13px;color:var(--muted);line-height:1.75}
.about-grid{display:grid;grid-template-columns:340px 1fr;gap:56px;align-items:start}
.about-grid img{border-radius:18px;width:100%}
.timeline{list-style:none;margin:0;padding:0}
.timeline li{display:grid;grid-template-columns:130px 1fr;gap:20px;padding:14px 0;border-bottom:1px dashed var(--line);font-size:15px}
.timeline b{color:var(--blue);font-weight:600}
.placeholder{border:1.5px dashed #C9D4DF;background:#FBFCFD;border-radius:16px;padding:30px;text-align:center}
.placeholder .ph-tag{display:inline-block;font-size:11px;letter-spacing:1px;color:#7A8794;border:1px solid #D5DEE7;border-radius:999px;padding:3px 12px;margin-bottom:14px}
.placeholder h3{font-size:16px;color:#55636F}
.placeholder p{font-size:13px;color:#8A97A3;margin:8px 0 0;line-height:1.8}
.ph-video{aspect-ratio:16/9;display:flex;align-items:center;justify-content:center;background:#EDF1F5;border-radius:12px;color:#8A97A3;font-size:13px;margin-bottom:12px}
details{background:#fff;border:1px solid var(--line);border-radius:12px;margin-bottom:12px;overflow:hidden}
summary{cursor:pointer;padding:18px 22px;font-weight:600;font-size:15px;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:16px}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";color:var(--blue);font-size:20px;font-weight:400;flex-shrink:0}
details[open] summary::after{content:"−"}
details .ans{padding:0 22px 18px;color:var(--muted);font-size:14px;line-height:1.9}
.faq-cat{margin:0 0 18px;font-size:13px;color:var(--accent);letter-spacing:1px;font-weight:600}
.cta-band{background:var(--deep);color:#fff;border-radius:22px;padding:54px;text-align:center}
.cta-band h2{color:#fff}
.cta-band p{color:#C6D7E8;max-width:620px;margin:16px auto 0;font-size:15px}
.cta-band .btn-row{justify-content:center}
.cta-band .btn-o{background:transparent;border-color:rgba(255,255,255,.4);color:#fff}
footer{background:#152331;color:#9FB0C0;padding:56px 0 34px;font-size:13px;margin-top:20px}
.f-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:40px;padding-bottom:36px}
.f-grid h4{color:#fff;font-size:14px;margin-bottom:14px}
.f-grid a{display:block;padding:4px 0;color:#9FB0C0}
.f-grid a:hover{color:#fff}
.f-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:22px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:12px}
.f-bottom a{color:#9FB0C0}
.notice{background:#FFF8F3;border:1px solid #F3D9C8;border-radius:12px;padding:16px 20px;font-size:13px;color:#8A5A3C;line-height:1.8}
@media(max-width:900px){
 .hero-grid,.about-grid{grid-template-columns:1fr;gap:36px}
 .grid3,.grid4,.f-grid{grid-template-columns:1fr 1fr}
 .nav-links{gap:16px;overflow-x:auto;-webkit-overflow-scrolling:touch}
 .nav-inner{gap:14px}
 .course-row{grid-template-columns:40px 1fr;gap:10px}
 .course-row .cb,.course-row .cd{grid-column:2}
 .sec{padding:60px 0}
 .cta-band{padding:36px 22px}
}
@media(max-width:600px){
 .grid3,.grid4,.grid2,.f-grid{grid-template-columns:1fr}
 img.nav-logo{height:32px}
 .btn-nav{padding:7px 14px;font-size:12px}
 .stats{grid-template-columns:repeat(2,1fr);gap:18px}
 .stat b{font-size:22px}
 .timeline li{grid-template-columns:1fr;gap:2px}
 .sec{padding:48px 0}
}