/* roulang page: index */
:root{
      --blue:#2161d1;
      --blue-dark:#17479d;
      --blue-soft:#eaf2ff;
      --teal:#168f87;
      --orange:#e98945;
      --ink:#17243a;
      --muted:#6c7890;
      --line:#e5eaf2;
      --bg:#f6f8fc;
      --white:#fff;
      --radius:14px;
      --shadow:0 12px 32px rgba(31,55,96,.09);
      --shadow-hover:0 18px 38px rgba(31,55,96,.15);
      --container:1180px;
    }
    *{box-sizing:border-box;margin:0;padding:0}
    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(--bg);line-height:1.7}
    a{color:inherit;text-decoration:none}
    img{display:block;width:100%;height:100%;object-fit:cover}
    button,input{font:inherit}
    button{cursor:pointer}
    :focus-visible{outline:3px solid rgba(33,97,209,.35);outline-offset:3px}
    .container{width:min(var(--container),calc(100% - 48px));margin:auto}
    .site-header{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.96);border-bottom:1px solid var(--line);backdrop-filter:blur(12px)}
    .nav-wrap{height:76px;display:flex;align-items:center;justify-content:space-between;gap:28px}
    .brand{display:flex;align-items:center;gap:11px;font-size:18px;font-weight:800;white-space:nowrap}
    .brand-mark{width:38px;height:38px;border-radius:10px;background:var(--blue);color:#fff;display:grid;place-items:center;font-weight:900;box-shadow:0 7px 15px rgba(33,97,209,.22)}
    .nav-links{display:flex;align-items:center;gap:27px;font-size:14px;color:var(--muted)}
    .nav-links a{transition:.2s}
    .nav-links a:hover,.nav-links a.active{color:var(--blue)}
    .nav-action,.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:1px solid transparent;border-radius:9px;padding:11px 18px;font-weight:700;transition:.2s}
    .nav-action,.btn-primary{background:var(--blue);color:#fff;box-shadow:0 8px 16px rgba(33,97,209,.2)}
    .nav-action:hover,.btn-primary:hover{background:var(--blue-dark);transform:translateY(-2px)}
    .menu-btn{display:none;border:1px solid var(--line);background:#fff;border-radius:8px;width:42px;height:42px;font-size:21px;color:var(--ink)}
    .hero{position:relative;min-height:550px;display:flex;align-items:center;overflow:hidden;background:#102d59;color:#fff}
    .hero::before{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(12,35,71,.92) 0%,rgba(12,35,71,.72) 44%,rgba(12,35,71,.3) 100%),url("https://images.unsplash.com/photo-1489599849927-2ee91cede3ba?auto=format&fit=crop&w=1800&q=85") center/cover}
    .hero-content{position:relative;z-index:1;padding:88px 0 105px;max-width:760px}
    .eyebrow{display:inline-flex;align-items:center;gap:8px;color:#b9d2ff;font-size:13px;font-weight:800;letter-spacing:0;margin-bottom:18px}
    .eyebrow::before{content:"";width:24px;height:2px;background:var(--orange)}
    h1{font-size:clamp(38px,5vw,66px);line-height:1.15;letter-spacing:0;margin-bottom:22px}
    .hero h1 em{font-style:normal;color:#ffd19a}
    .hero-lead{font-size:18px;line-height:1.9;color:#e6efff;max-width:720px;margin-bottom:30px}
    .hero-actions{display:flex;flex-wrap:wrap;gap:12px}
    .btn-light{background:#fff;color:var(--blue)}
    .btn-light:hover{background:#eef4ff;transform:translateY(-2px)}
    .btn-outline-light{border-color:rgba(255,255,255,.55);color:#fff}
    .btn-outline-light:hover{background:rgba(255,255,255,.12)}
    section{padding:88px 0}
    section:nth-of-type(even){background:#fff}
    .section-head{display:flex;justify-content:space-between;align-items:end;gap:25px;margin-bottom:34px}
    .section-kicker{color:var(--blue);font-weight:800;font-size:13px;margin-bottom:7px}
    h2{font-size:32px;line-height:1.28;letter-spacing:0}
    .section-intro{max-width:560px;color:var(--muted);font-size:15px}
    .pain-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
    .pain-item{background:#fff;border:1px solid var(--line);padding:24px;border-radius:var(--radius);box-shadow:var(--shadow)}
    .pain-icon{width:38px;height:38px;border-radius:10px;background:var(--blue-soft);color:var(--blue);display:grid;place-items:center;font-weight:900;margin-bottom:15px}
    .pain-item h3{font-size:17px;margin-bottom:8px}
    .pain-item p,.card p,.channel p,.quote p,.guide-list p{color:var(--muted);font-size:14px}
    .steps{display:grid;grid-template-columns:repeat(4,1fr);gap:0;border-top:1px solid var(--line)}
    .step{padding:30px 26px 8px 0;border-right:1px solid var(--line);margin-right:26px}
    .step:last-child{border:0;margin:0}
    .step-num{font-size:38px;font-weight:900;color:var(--blue);line-height:1;margin-bottom:18px}
    .step h3{font-size:18px;margin-bottom:8px}
    .content-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
    .card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:.25s}
    .card:hover{transform:translateY(-5px);box-shadow:var(--shadow-hover)}
    .card-media{height:210px;position:relative;background:#dfe7f2}
    .card-media img{transition:.3s}
    .card:hover .card-media img{transform:scale(1.04)}
    .badge{position:absolute;left:12px;top:12px;background:var(--orange);color:#fff;border-radius:5px;padding:3px 8px;font-size:11px;font-weight:800}
    .card-body{padding:17px}
    .card h3{font-size:17px;line-height:1.4;margin-bottom:8px}
    .meta{display:flex;justify-content:space-between;gap:8px;color:var(--muted);font-size:12px}
    .rating{color:#d67827;font-weight:800}
    .content-grid.latest .card:nth-child(3n+1){grid-row:span 1}
    .content-grid.latest .card:nth-child(4n+2) .card-media{height:250px}
    .content-grid.latest .card:nth-child(5n+3){transform:translateY(18px)}
    .content-grid.latest .card:nth-child(5n+3):hover{transform:translateY(13px)}
    .popular-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
    .popular-card{display:flex;background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:.2s}
    .popular-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-hover)}
    .popular-card .card-media{width:43%;height:164px;flex:none}
    .popular-card .card-body{padding:18px}
    .channel-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:14px}
    .channel{padding:24px 20px;background:#f8fbff;border:1px solid #dce8f8;border-radius:12px;transition:.2s}
    .channel:hover{border-color:var(--blue);background:#fff;transform:translateY(-3px)}
    .channel h3{font-size:18px;margin-bottom:8px}
    .channel span{display:inline-block;color:var(--teal);font-size:12px;margin-top:15px;font-weight:700}
    .metric-band{background:#172f56!important;color:#fff}
    .metric-band .section-kicker{color:#9fc1ff}
    .metric-band .section-intro{color:#c9d7eb}
    .metrics{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:rgba(255,255,255,.16);margin-top:35px}
    .metric{padding:27px 24px;background:#172f56}
    .metric strong{display:block;font-size:38px;line-height:1.2;color:#fff}
    .metric span{color:#b7c8df;font-size:13px}
    .rank-wrap{display:grid;grid-template-columns:1fr 1fr;gap:18px}
    .rank-list{list-style:none}
    .rank-item{display:grid;grid-template-columns:38px 1fr auto auto;align-items:center;gap:12px;padding:16px 14px;border-bottom:1px solid var(--line);background:#fff}
    .rank-item:first-child{border-radius:10px 10px 0 0}
    .rank-no{font-size:20px;font-weight:900;color:#a4aec0}
    .rank-item:nth-child(-n+3) .rank-no{color:var(--orange)}
    .rank-title{font-weight:700}
    .rank-tag{font-size:11px;color:var(--teal);background:#e8f7f5;padding:3px 7px;border-radius:4px}
    .heat{font-size:12px;color:var(--muted)}
    .quotes{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
    .quote{padding:26px;background:#f8fbff;border-left:4px solid var(--blue);border-radius:0 12px 12px 0}
    .quote p{font-size:16px;color:var(--ink);line-height:1.8;margin-bottom:18px}
    .quote cite{font-style:normal;font-size:13px;color:var(--muted)}
    .scene-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
    .scene{min-height:170px;padding:24px;background:#fff;border:1px solid var(--line);border-radius:12px;display:flex;flex-direction:column;justify-content:space-between}
    .scene h3{font-size:18px}
    .scene small{color:var(--blue);font-weight:700}
    .topics{display:grid;grid-template-columns:1.2fr .8fr .8fr;gap:18px}
    .topic{min-height:220px;padding:25px;border-radius:12px;color:#fff;background-size:cover;background-position:center;position:relative;overflow:hidden;display:flex;align-items:end}
    .topic::before{content:"";position:absolute;inset:0;background:linear-gradient(0deg,rgba(13,31,60,.85),transparent 75%)}
    .topic div{position:relative}
    .topic h3{font-size:21px;margin-bottom:5px}
    .topic p{font-size:13px;color:#e5efff}
    .topic.large{grid-row:span 2;min-height:458px}
    .news-list{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
    .news{display:flex;gap:15px;padding:14px;background:#fff;border:1px solid var(--line);border-radius:10px}
    .news img{width:100px;height:78px;border-radius:7px;flex:none}
    .news h3{font-size:15px;line-height:1.45;margin-bottom:7px}
    .news time{color:var(--muted);font-size:12px}
    .guide{display:grid;grid-template-columns:.8fr 1.2fr;gap:50px;align-items:center}
    .guide-image{height:330px;border-radius:14px;overflow:hidden;box-shadow:var(--shadow)}
    .guide-list{list-style:none}
    .guide-list li{display:grid;grid-template-columns:38px 1fr;gap:15px;padding:17px 0;border-bottom:1px solid var(--line)}
    .guide-list b{width:30px;height:30px;display:grid;place-items:center;border-radius:50%;background:var(--blue-soft);color:var(--blue)}
    .guide-list h3{font-size:17px;margin-bottom:3px}
    .faq-list{max-width:850px;margin:auto}
    details{background:#fff;border:1px solid var(--line);border-radius:10px;margin-bottom:12px;padding:19px 22px}
    summary{cursor:pointer;font-weight:800;list-style:none;display:flex;justify-content:space-between;gap:20px}
    summary::-webkit-details-marker{display:none}
    summary::after{content:"+";color:var(--blue);font-size:22px;line-height:1}
    details[open] summary::after{content:"−"}
    details p{color:var(--muted);font-size:14px;margin-top:14px;padding-right:35px}
    .cta{padding:72px 0;background:var(--blue)!important;color:#fff;text-align:center}
    .cta h2{font-size:36px;margin-bottom:12px}
    .cta p{color:#dce8ff;max-width:650px;margin:0 auto 25px}
    .site-footer{background:#10213d;color:#d2dced;padding:55px 0 22px}
    .footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:35px;padding-bottom:38px}
    .footer-brand{color:#fff;font-size:20px;font-weight:800;margin-bottom:14px}
    .footer-grid p{font-size:13px;color:#aebdd3;max-width:280px}
    .footer-col h3{font-size:14px;color:#fff;margin-bottom:14px}
    .footer-col a{display:block;color:#aebdd3;font-size:13px;margin:8px 0;transition:.2s}
    .footer-col a:hover{color:#fff}
    .copyright{border-top:1px solid rgba(255,255,255,.12);padding-top:19px;color:#91a2bb;font-size:12px}
    @media(max-width:1200px){
      .content-grid{grid-template-columns:repeat(3,1fr)}
      .channel-grid{grid-template-columns:repeat(3,1fr)}
    }
    @media(max-width:900px){
      .nav-links{gap:14px}
      .nav-action{padding:9px 12px}
      .pain-grid,.scene-grid{grid-template-columns:repeat(2,1fr)}
      .steps{grid-template-columns:repeat(2,1fr);gap:15px}
      .step{border-right:0;margin:0;border-bottom:1px solid var(--line)}
      .popular-grid,.news-list{grid-template-columns:1fr 1fr}
      .quotes{grid-template-columns:1fr}
      .topics{grid-template-columns:1fr 1fr}
      .topic.large{grid-row:auto;min-height:220px}
      .guide{grid-template-columns:1fr;gap:28px}
      .footer-grid{grid-template-columns:1.5fr 1fr 1fr}
    }
    @media(max-width:680px){
      .container{width:min(100% - 32px,var(--container))}
      .nav-wrap{height:68px}
      .menu-btn{display:block}
      .nav-links{position:absolute;display:none;left:16px;right:16px;top:76px;background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);padding:10px;border-radius:10px;flex-direction:column;align-items:stretch;gap:0}
      .nav-links.open{display:flex}
      .nav-links a{padding:12px 14px;border-bottom:1px solid var(--line)}
      .nav-links a:last-child{border-bottom:0}
      .nav-action{display:none}
      .hero{min-height:520px}
      .hero-content{padding:70px 0 90px}
      h1{font-size:42px}
      .hero-lead{font-size:16px}
      section{padding:65px 0}
      .section-head{display:block}
      .section-intro{margin-top:13px}
      h2{font-size:27px}
      .pain-grid,.content-grid,.popular-grid,.channel-grid,.scene-grid,.news-list,.topics{grid-template-columns:1fr}
      .content-grid.latest .card:nth-child(5n+3){transform:none}
      .content-grid.latest .card:nth-child(5n+3):hover{transform:translateY(-5px)}
      .card-media,.content-grid.latest .card:nth-child(4n+2) .card-media{height:220px}
      .popular-card .card-media{height:150px}
      .metrics{grid-template-columns:1fr 1fr}
      .metric strong{font-size:30px}
      .rank-wrap{grid-template-columns:1fr}
      .rank-item{grid-template-columns:31px 1fr auto}
      .rank-item .heat{display:none}
      .topic.large{min-height:250px}
      .topics .topic{min-height:185px}
      .guide-image{height:240px}
      .cta h2{font-size:29px}
      .footer-grid{grid-template-columns:1fr 1fr}
      .footer-grid > :first-child{grid-column:1/-1}
    }
    @media(max-width:480px){
      .hero-actions{flex-direction:column;align-items:stretch}
      .btn{width:100%}
      .steps{grid-template-columns:1fr}
      .metrics{grid-template-columns:1fr 1fr}
      .footer-grid{grid-template-columns:1fr}
      .footer-grid > :first-child{grid-column:auto}
    }