/* ===== FOCO 官网 · C 端深蓝+亮青 · 自绘视觉 ===== */
:root{
  --navy:#003459; --navy-deep:#081b4d; --navy-2:#102a6b;
  --cyan:#00a7e1; --cyan-soft:#eaf1ff;
  --ink:#1a1f24; --muted:#5f6b85; --muted-2:#8e98a8;
  --bg:#fff; --bg-soft:#f8faff; --bg-soft-2:#eef2f8; --line:#e4eaf5;
  --ok:#20a66a; --err:#ef4d61;
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:ui-sans-serif,system-ui,-apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",sans-serif;color:var(--ink);line-height:1.65;background:var(--bg);-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
strong{font-weight:700;color:var(--navy)}
.dim{color:var(--muted-2)}
.accent{color:var(--cyan)}
.wrap{max-width:1080px;margin:0 auto;padding:0 24px}
.narrow{max-width:680px;margin:0 auto}
.center{text-align:center}
.left{text-align:left}

/* buttons */
.btn{display:inline-block;font-weight:600;cursor:pointer;border-radius:8px;border:1px solid transparent;transition:all .15s ease;padding:10px 22px}
.btn-sm{padding:8px 16px;font-size:14px}
.btn-lg{padding:15px 30px;font-size:16px}
.btn-primary{background:var(--navy);color:#fff;border-color:var(--navy)}
.btn-primary:hover{background:var(--navy-deep);transform:translateY(-1px);box-shadow:0 10px 28px rgba(0,52,89,.25)}
.btn-ghost{background:transparent;color:var(--navy);border-color:var(--line)}
.btn-ghost:hover{border-color:var(--navy)}

/* nav */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.88);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:62px}
.brand{font-weight:800;font-size:16px;color:var(--navy);display:flex;align-items:center;gap:6px}
.brand-icon{height:24px;width:auto}
.brand-dot{margin:0 6px;color:var(--muted-2);font-weight:400}
.nav-links{display:flex;align-items:center;gap:30px}
.nav-links a{color:var(--muted);font-size:14px}
.nav-links a:hover{color:var(--navy)}
.nav-links .btn-primary{color:#fff}

/* hero */
.hero{position:relative;color:#fff;padding:128px 0 112px;overflow:hidden}
.hero::before{content:"";position:absolute;inset:0;background:linear-gradient(135deg,rgba(8,27,77,0.85) 0%,rgba(0,52,89,0.85) 55%,rgba(16,42,107,0.9) 100%),url('/hero-bg.png') center/cover no-repeat;z-index:-1;animation:hero-bg-zoom 20s ease-out forwards}
@keyframes hero-bg-zoom{0%{transform:scale(1)}100%{transform:scale(1.08)}}
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:center}
.eyebrow{font-size:13px;letter-spacing:.14em;text-transform:uppercase;color:var(--cyan);margin-bottom:22px}
.hero h1{font-size:clamp(38px,6vw,62px);line-height:1.1;font-weight:800;letter-spacing:-.02em}
.lead{margin:26px 0 36px;font-size:clamp(16px,1.8vw,18px);color:rgba(255,255,255,.85);max-width:560px}
.lead strong{color:#fff}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap}
.hero .btn-primary{background:#fff;color:var(--navy);border-color:#fff}
.hero .btn-primary:hover{background:var(--bg-soft)}
.hero .btn-ghost{color:#fff;border-color:rgba(255,255,255,.5)}
.hero .btn-ghost:hover{border-color:#fff;background:rgba(255,255,255,.12)}
.hero-visual{display:flex;justify-content:center}
.mastery-ring{width:100%;max-width:380px;filter:drop-shadow(0 20px 60px rgba(0,167,225,.25));animation:glow-pulse 4s ease-in-out infinite;transition:transform .5s cubic-bezier(0.34,1.56,0.64,1)}
.mastery-ring:hover{transform:scale(1.08)}
.mastery-ring .r-label{font-size:16px;font-weight:600;fill:#fff;transition:fill .3s ease}
.mastery-ring:hover .r-label{fill:var(--cyan)}
.ring-arc{transform-box:fill-box;transform-origin:center;animation:draw 2s ease forwards,spin-slow 24s linear 2s infinite;transition:stroke-width .4s ease}
.mastery-ring:hover .ring-arc{stroke-width:8;filter:drop-shadow(0 0 10px var(--cyan))}
@keyframes glow-pulse{0%,100%{filter:drop-shadow(0 20px 60px rgba(0,167,225,.22))}50%{filter:drop-shadow(0 20px 80px rgba(0,167,225,.4))}}
@keyframes spin-slow{to{transform:rotate(360deg)}}

/* trust */
.trust{padding:32px 0;background:var(--bg-soft);border-bottom:1px solid var(--line)}
.trust-row{display:flex;justify-content:space-between;gap:24px;flex-wrap:wrap}
.trust-item{display:flex;flex-direction:column;gap:2px;min-width:120px}
.t-num{font-size:28px;font-weight:800;color:var(--navy)}
.t-label-strong{font-size:15px;font-weight:700;color:var(--navy)}
.t-label{font-size:13px;color:var(--muted)}

/* problem */
.problem{padding:120px 0;background:var(--bg-soft)}
.big-q{font-size:clamp(24px,3.4vw,34px);color:var(--muted);font-weight:500}
.big-a{font-size:clamp(32px,5.5vw,50px);font-weight:800;margin:18px 0 36px;letter-spacing:-.02em;color:var(--navy)}
.big-a .accent{color:var(--cyan)}
.muted-body{color:var(--muted);font-size:17px;margin-bottom:18px}
.inline-cta{margin-top:12px}
.inline-cta a{color:var(--cyan);font-weight:600}

/* method */
.method{padding:120px 0}
.sec-title{font-size:clamp(28px,4vw,38px);font-weight:800;letter-spacing:-.02em;line-height:1.2;color:var(--navy)}
.sec-title.light{color:#fff}
.sec-title.left{text-align:left}
.sec-sub{color:var(--muted);max-width:620px;margin:18px auto 56px;font-size:16px}
.sec-sub.light{color:rgba(255,255,255,.7)}
.steps{list-style:none;max-width:760px;margin:0 auto}
.step{display:flex;gap:26px;padding:30px 0;border-top:1px solid var(--line);align-items:flex-start}
.step.last{border-bottom:1px solid var(--line)}
.step-char{flex:0 0 auto;width:54px;height:54px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:22px;font-weight:700;color:#fff;background:var(--navy)}
.step h3{font-size:19px;margin-bottom:5px}
.step p{color:var(--muted);font-size:15px}
.map{color:var(--cyan);font-weight:600;font-size:13px}

/* flow (loop) */
.flow{padding:120px 0;background:linear-gradient(135deg,var(--navy) 0%,var(--navy-2) 100%);color:#fff}
.loop{display:flex;align-items:center;justify-content:center;gap:18px;flex-wrap:wrap;margin:48px 0 24px;position:relative}
.loop-node{background:rgba(255,255,255,.06);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border:1px solid rgba(255,255,255,.15);border-radius:16px;padding:22px 24px;min-width:140px;text-align:center;box-shadow:0 8px 32px rgba(0,0,0,0.12)}
.ln-icon{display:inline-block;font-size:13px;font-weight:700;color:var(--navy);background:var(--cyan);width:28px;height:28px;line-height:28px;border-radius:50%;margin-bottom:8px}
.loop-node h3{font-size:19px;color:#fff;margin-bottom:2px}
.loop-node p{font-size:13px;color:rgba(255,255,255,.65)}
.loop-arrow{color:var(--cyan);font-size:22px;font-weight:700}
.loop-back{display:block;width:100%;text-align:center;color:var(--cyan);font-size:14px;margin-top:10px}

/* features bento */
.features{padding:120px 0}
.bento{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:56px}
.bento-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px;transition:all .3s cubic-bezier(0.25, 0.8, 0.25, 1);box-shadow:0 4px 20px rgba(0,52,89,.03)}
.bento-card:hover{transform:translateY(-4px);border-color:var(--cyan);box-shadow:0 16px 40px rgba(0,52,89,.08), 0 0 0 1px var(--cyan)}
.bento-card.big{grid-column:span 2;grid-row:span 1}
.b-visual{height:110px;margin-bottom:14px;display:flex;align-items:center;justify-content:center;background:var(--bg-soft);border-radius:10px}
.b-visual svg{width:80%;height:auto;max-height:90px}
.bento-card h3{font-size:17px;margin-bottom:5px;color:var(--navy)}
.bento-card p{font-size:14px;color:var(--muted)}
.b-visual.dots{gap:8px}
.b-visual.dots span{width:14px;height:14px;border-radius:50%;background:var(--cyan);opacity:.4}
.b-visual.dots span:nth-child(odd){opacity:.8;background:var(--navy)}
.b-visual.list{flex-direction:column;gap:6px;width:70%}
.b-visual.list .row{width:100%;height:9px;border-radius:4px}
.b-visual.list .ok{background:var(--ok);opacity:.6}
.b-visual.list .err{background:var(--err);opacity:.5}
.b-visual.bubble{flex-direction:column;gap:6px;width:100%;padding:0 16px}
.bub{font-size:11px;padding:5px 10px;border-radius:10px;background:#fff;border:1px solid var(--line);color:var(--muted);align-self:flex-start;max-width:80%}
.bub.ai{background:var(--cyan-soft);color:var(--navy);border-color:var(--cyan-soft);align-self:flex-end}

/* ai */
.ai{padding:120px 0;background:var(--navy);color:#fff}
.ai .sec-title{color:#fff}
.ai-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.ai-points{list-style:none;margin-top:24px}
.ai-points li{padding:10px 0;color:rgba(255,255,255,.82);border-bottom:1px solid rgba(255,255,255,.1)}
.ai-chat{display:flex;flex-direction:column;gap:10px;background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.12);border-radius:16px;padding:24px}
.ai-chat .bub{max-width:85%;font-size:14px;padding:10px 14px}
.ai-chat .bub.user{background:rgba(255,255,255,.1);color:#fff;align-self:flex-start;border:none}
.ai-chat .bub.ai{background:var(--cyan);color:#081b4d;align-self:flex-end;border:none}

/* qbank */
.qbank{padding:120px 0;background:var(--bg-soft)}
.qbank-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.qbank-mock{display:flex;flex-direction:column;gap:10px}
.qcard{display:flex;align-items:center;gap:12px;background:#fff;border:1px solid var(--line);border-radius:10px;padding:14px 16px}
.qno{font-weight:700;color:var(--navy);font-size:14px;width:56px}
.qtag{font-size:13px;color:var(--muted);flex:1}
.qstatus{font-size:12px;font-weight:600;padding:3px 10px;border-radius:12px}
.qstatus.ok{background:rgba(32,166,106,.12);color:var(--ok)}
.qstatus.err{background:rgba(239,77,97,.12);color:var(--err)}
.qstatus.wait{background:var(--bg-soft-2);color:var(--muted)}

/* analytics */
.analytics{padding:120px 0}
.analytics-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.chart-card{background:var(--bg-soft);border:1px solid var(--line);border-radius:16px;padding:28px;display:flex;gap:24px;align-items:center;box-shadow:0 10px 30px rgba(0,52,89,.04)}
.donut{position:relative;width:120px;height:120px;flex-shrink:0}
.donut svg{width:100%;height:100%}
.donut span{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);font-size:22px;font-weight:800;color:var(--navy);text-align:center}
.donut span small{display:block;font-size:11px;font-weight:400;color:var(--muted)}
.bars{flex:1;display:flex;align-items:flex-end;gap:8px;height:120px}
.bars span{flex:1;background:linear-gradient(var(--cyan),var(--navy));border-radius:4px 4px 0 0;opacity:.85}

/* dashboard */
.dashboard{padding:120px 0;background:var(--bg-soft)}
.browser-mock{max-width:860px;margin:48px auto 0;background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 30px 80px rgba(0,52,89,.12), 0 10px 20px rgba(0,52,89,.04);overflow:hidden;text-align:left}
.bm-bar{display:flex;align-items:center;gap:7px;padding:12px 16px;background:var(--bg-soft-2);border-bottom:1px solid var(--line)}
.bm-bar .dot{width:11px;height:11px;border-radius:50%;background:#cbd5e5}
.bm-bar .dot.r{background:#ef4d61}.bm-bar .dot.y{background:#f5c518}.bm-bar .dot.g{background:#20a66a}
.bm-url{margin-left:14px;font-size:12px;color:var(--muted)}
.bm-body{padding:20px 24px}
.bm-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}
.bm-head b{font-size:16px;color:var(--navy)}
.bm-badge{background:var(--cyan-soft);color:var(--navy);font-size:12px;font-weight:600;padding:4px 12px;border-radius:12px}
.bm-topics{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-bottom:16px}
.bm-topic{display:flex;align-items:center;gap:8px;padding:8px 12px;background:var(--bg-soft);border-radius:8px;font-size:13px;color:var(--ink)}
.bm-topic .dot{width:8px;height:8px;border-radius:50%;background:var(--line);flex-shrink:0}
.bm-topic .dot.ok{background:var(--ok)}
.bm-topic .dot.warn{background:#f5c518}
.bm-topic .pct{margin-left:auto;font-weight:600;color:var(--navy);font-size:12px}
.bm-graph{background:var(--bg-soft);border-radius:8px;padding:8px}
.bm-graph svg{width:100%;height:40px}

/* testimonials */
.testi{padding:120px 0}
.testi-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:48px}
.testi-card{background:var(--bg-soft);border:1px solid var(--line);border-radius:14px;padding:28px;font-size:16px;color:var(--ink);line-height:1.7;box-shadow:0 8px 24px rgba(0,52,89,.03)}
.testi-card cite{display:block;margin-top:14px;font-size:13px;color:var(--muted);font-style:normal}
.testi-note{margin-top:24px;font-size:13px}

/* faq */
.faq{padding:120px 0;background:var(--bg-soft)}
.accordion{margin-top:40px}
.acc{background:#fff;border:1px solid var(--line);border-radius:10px;margin-bottom:10px;overflow:hidden}
.acc summary{padding:18px 22px;font-weight:600;cursor:pointer;list-style:none;color:var(--navy)}
.acc summary::-webkit-details-marker{display:none}
.acc[open] summary{border-bottom:1px solid var(--line)}
.acc p{padding:16px 22px;color:var(--muted);font-size:15px}

/* cta final */
.cta-final{padding:130px 0;background:linear-gradient(135deg,var(--navy-deep),var(--navy));color:#fff}
.cta-final h2{font-size:clamp(28px,4vw,38px);font-weight:800;letter-spacing:-.02em;margin-bottom:14px}
.cta-final p{color:rgba(255,255,255,.8);margin-bottom:32px}
.cta-final .btn-primary{background:#fff;color:var(--navy);border-color:#fff}

/* footer */
.footer{background:var(--navy-deep);color:rgba(255,255,255,.7);padding:28px 0;font-size:13px}
.footer-inner{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
.footer .dim{color:rgba(255,255,255,.4)}

/* reveal animation */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
.reveal.in{opacity:1;transform:none}

/* responsive */
@media(max-width:900px){
  .hero-grid,.ai-grid,.qbank-grid,.analytics-grid{grid-template-columns:1fr;gap:36px}
  .hero-visual{order:-1}
  .bento{grid-template-columns:repeat(2,1fr)}
  .bento-card.big{grid-column:span 2}
  .testi-grid{grid-template-columns:1fr}
}
@media(max-width:640px){
  .nav-links{gap:16px}
  .nav-links a:not(.btn){display:none}
  .bento{grid-template-columns:1fr}
  .bento-card.big{grid-column:auto}
  .step{gap:16px;padding:24px 0}
  .step-char{width:46px;height:46px;font-size:19px}
  .hero{padding:88px 0 72px}
  .loop{gap:10px}
  .loop-node{min-width:120px;padding:16px}
  .trust-row{justify-content:center;text-align:center}
}
@media(prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none}
  .ring-arc{animation:none}
  *{scroll-behavior:auto!important}
}
@keyframes draw{from{stroke-dashoffset:820}to{stroke-dashoffset:0}}