/* roulang page: index */
:root{
      --ink:#172d42;--muted:#63778b;--blue:#1768a6;--blue-dark:#10517f;
      --cyan:#dff4f6;--surface:#fff;--bg:#f4f8fc;--line:#dce6ef;
      --mint:#dff2e9;--coral:#f6e6df;--gold:#f1e9d3;
      --radius:10px;--shadow:0 12px 32px rgba(27,57,82,.08);
      --container:1160px;
    }
    *{box-sizing:border-box}
    html{scroll-behavior:smooth;scroll-padding-top:84px}
    body{margin:0;background:var(--bg);color:var(--ink);font-family:Inter,"Noto Sans SC","Microsoft YaHei",sans-serif;font-size:15px;line-height:1.7}
    a{color:inherit;text-decoration:none}
    img{display:block;width:100%;height:100%;object-fit:cover}
    button{font:inherit}
    :focus-visible{outline:3px solid #68b7cc;outline-offset:3px}
    .container{width:min(var(--container),calc(100% - 40px));margin-inline:auto}
    .topline{height:4px;background:linear-gradient(90deg,#1768a6 0 42%,#47a9b4 42% 68%,#d8b878 68%)}
    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{min-height:72px;display:flex;align-items:center;gap:30px}
    .brand{display:flex;align-items:center;gap:11px;min-width:max-content;font-weight:800;font-size:16px;letter-spacing:0}
    .brand-mark{width:36px;height:36px;border-radius:9px;background:var(--blue);color:white;display:grid;place-items:center;font-size:18px}
    nav{display:flex;align-items:center;gap:25px;margin-left:auto}
    nav a{color:#52687b;font-size:14px;font-weight:650;transition:color .2s}
    nav a:hover,nav a.active{color:var(--blue)}
    .nav-cta{display:inline-flex;align-items:center;justify-content:center;padding:10px 16px;border-radius:7px;background:var(--blue);color:white;font-weight:700;transition:.2s}
    .nav-cta:hover{background:var(--blue-dark);transform:translateY(-1px)}
    .menu-toggle{display:none;border:1px solid var(--line);background:white;color:var(--ink);border-radius:7px;width:42px;height:42px;cursor:pointer}
    .hero{padding:42px 0 34px}
    .hero-shell{min-height:420px;display:grid;grid-template-columns:1.05fr .95fr;background:#e9f1f6;border-radius:12px;overflow:hidden;box-shadow:var(--shadow)}
    .hero-copy{padding:48px 48px 42px;display:flex;flex-direction:column;justify-content:center}
    .eyebrow{display:flex;align-items:center;gap:9px;color:var(--blue);font-size:12px;font-weight:800;letter-spacing:0}
    .eyebrow:before{content:"";width:22px;height:2px;background:#47a9b4}
    h1{font-size:38px;line-height:1.25;margin:15px 0 10px;letter-spacing:0;max-width:570px}
    .highlight{color:var(--blue)}
    .hero-sub{font-size:17px;font-weight:700;margin:0 0 12px;color:#35516b}
    .hero-copy>p{max-width:570px;color:#536b80;margin:0 0 21px}
    .hero-actions{display:flex;align-items:center;gap:11px;flex-wrap:wrap}
    .button{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:11px 17px;border:1px solid transparent;border-radius:7px;font-weight:750;transition:.2s;cursor:pointer}
    .button-primary{background:var(--blue);color:white}
    .button-primary:hover{background:var(--blue-dark);transform:translateY(-1px)}
    .button-quiet{border-color:#b9ccda;background:rgba(255,255,255,.65);color:#34546e}
    .button-quiet:hover{background:white;border-color:var(--blue)}
    .hero-visual{position:relative;min-height:360px;overflow:hidden}
    .hero-visual img{position:absolute;inset:0;object-position:center 36%}
    .hero-visual:after{content:"";position:absolute;inset:40% 0 0;background:linear-gradient(transparent,rgba(13,35,52,.72))}
    .cover-note{position:absolute;z-index:1;bottom:24px;left:26px;right:26px;color:white}
    .cover-note strong{display:block;font-size:21px}
    .cover-note span{font-size:13px;color:#e7eff3}
    .hero-stats{display:flex;gap:24px;margin-top:25px;padding-top:17px;border-top:1px solid #cedce5}
    .hero-stats b{display:block;font-size:17px;color:#234866}
    .hero-stats span{font-size:12px;color:var(--muted)}
    main section{padding:54px 0}
    .section-white{background:#fff}
    .section-tint{background:#edf4f8}
    .section-head{display:flex;align-items:end;justify-content:space-between;gap:24px;margin-bottom:24px}
    .section-head h2{font-size:25px;line-height:1.3;margin:0;letter-spacing:0}
    .section-head p{max-width:680px;margin:8px 0 0;color:var(--muted)}
    .section-link{font-weight:750;color:var(--blue);white-space:nowrap}
    .section-link:hover{color:var(--blue-dark)}
    .metrics{display:grid;grid-template-columns:repeat(4,1fr);border:1px solid var(--line);background:white;border-radius:9px;overflow:hidden}
    .metric{padding:21px 24px;border-right:1px solid var(--line)}
    .metric:last-child{border:0}
    .metric strong{display:block;font-size:24px;color:var(--blue);line-height:1.2}
    .metric span{font-size:13px;color:var(--muted)}
    .feature-row{display:grid;grid-template-columns:1.05fr .95fr;gap:34px;align-items:center}
    .feature-image{height:310px;border-radius:9px;overflow:hidden;box-shadow:var(--shadow)}
    .feature-image img{object-position:center 30%}
    .feature-copy h2{font-size:26px;line-height:1.35;margin:0 0 12px}
    .feature-copy p{color:var(--muted);margin:0 0 18px}
    .tag-row{display:flex;flex-wrap:wrap;gap:8px}
    .tag{display:inline-flex;align-items:center;padding:5px 10px;border-radius:5px;background:#e8f1f7;color:#41617b;font-size:12px;font-weight:700}
    .tag.mint{background:var(--mint);color:#35634d}
    .tag.gold{background:var(--gold);color:#746034}
    .grid-4{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}
    .topic{padding:21px;background:white;border:1px solid var(--line);border-radius:8px;transition:transform .2s,box-shadow .2s,border-color .2s}
    .topic:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:#b8d3e3}
    .topic-index{font-size:12px;font-weight:800;color:#4c91ad}
    .topic h3{font-size:17px;margin:9px 0 7px}
    .topic p{font-size:13px;color:var(--muted);margin:0}
    .topic .tag{margin-top:15px}
    .editorial{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
    .editorial-item{display:grid;grid-template-columns:92px 1fr;min-height:130px;background:white;border:1px solid var(--line);border-radius:8px;overflow:hidden}
    .editorial-item img{min-height:130px}
    .editorial-copy{padding:16px}
    .editorial-copy small{color:var(--blue);font-weight:750}
    .editorial-copy h3{font-size:15px;line-height:1.45;margin:6px 0}
    .editorial-copy p{font-size:12px;color:var(--muted);margin:0}
    .ranking{display:grid;grid-template-columns:1fr 1fr;gap:0 35px}
    .rank-item{display:grid;grid-template-columns:38px 1fr auto;align-items:center;gap:12px;padding:14px 0;border-bottom:1px solid var(--line)}
    .rank-no{font-size:17px;font-weight:850;color:#8ba0b1}
    .rank-no.top{color:var(--blue)}
    .rank-title{font-weight:750}
    .rank-meta{font-size:12px;color:var(--muted)}
    .score{font-size:13px;font-weight:800;color:#477b62}
    .split-band{display:grid;grid-template-columns:.82fr 1.18fr;gap:30px;align-items:center;background:#173d5b;color:#fff;border-radius:10px;padding:30px}
    .split-band h2{font-size:23px;margin:0 0 8px}
    .split-band p{margin:0;color:#d1e0e9}
    .split-points{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
    .split-point{padding:16px;border-left:2px solid #63b1bd;background:rgba(255,255,255,.07)}
    .split-point strong{display:block;margin-bottom:5px}
    .split-point span{font-size:12px;color:#d1e0e9}
    .news-list{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
    .news{background:white;border:1px solid var(--line);border-radius:8px;overflow:hidden;transition:.2s}
    .news:hover{box-shadow:var(--shadow);transform:translateY(-2px)}
    .news-image{height:150px;overflow:hidden}
    .news-image img{transition:transform .35s}
    .news:hover img{transform:scale(1.035)}
    .news-copy{padding:16px}
    .news-copy time{font-size:12px;color:var(--blue);font-weight:750}
    .news-copy h3{font-size:16px;margin:7px 0}
    .news-copy p{font-size:13px;color:var(--muted);margin:0}
    .assurance{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
    .assurance-item{display:flex;gap:13px;align-items:flex-start}
    .assurance-icon{flex:0 0 38px;height:38px;display:grid;place-items:center;background:#e0f0f2;color:#207184;border-radius:8px;font-weight:900}
    .assurance-item strong{display:block;margin-bottom:3px}
    .assurance-item p{font-size:13px;color:var(--muted);margin:0}
    .qa-list{display:grid;grid-template-columns:1fr 1fr;gap:14px}
    .qa{padding:19px 20px;background:white;border:1px solid var(--line);border-radius:8px}
    .qa h3{font-size:15px;margin:0 0 7px}
    .qa p{font-size:13px;color:var(--muted);margin:0}
    .age-note{padding:16px 18px;border-left:3px solid #d5b36c;background:#fbf8f0;color:#675b3d;font-size:13px}
    footer{background:#122e45;color:#e6eef4;padding:42px 0 18px}
    .footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:32px;padding-bottom:30px}
    .footer-brand{font-weight:800;font-size:17px}
    .footer-copy{font-size:13px;color:#b5c7d4;max-width:310px}
    .footer-col strong{display:block;margin-bottom:12px;font-size:14px}
    .footer-col a{display:block;margin:7px 0;color:#b5c7d4;font-size:13px}
    .footer-col a:hover{color:white}
    .copyright{padding-top:16px;border-top:1px solid rgba(255,255,255,.14);font-size:12px;color:#a8bbc9;display:flex;justify-content:space-between;gap:15px;flex-wrap:wrap}
    @media(max-width:1024px){
      .nav-wrap{gap:16px}.brand{font-size:14px}nav{gap:15px}
      .hero-copy{padding:35px}.grid-4{grid-template-columns:repeat(2,1fr)}
      .editorial{grid-template-columns:repeat(2,1fr)}
      .footer-grid{grid-template-columns:1.4fr 1fr 1fr}
      .footer-col:last-child{display:none}
    }
    @media(max-width:768px){
      .container{width:min(100% - 30px,var(--container))}
      .nav-wrap{min-height:64px;flex-wrap:wrap}
      .brand{margin-right:auto}
      .menu-toggle{display:block}
      nav{display:none;order:3;width:100%;margin:0;padding:8px 0 16px;gap:0;align-items:stretch;flex-direction:column}
      nav.open{display:flex}
      nav a{padding:10px 4px;border-top:1px solid var(--line)}
      .nav-cta{margin:8px 0 0}
      .hero{padding:22px 0}
      .hero-shell{grid-template-columns:1fr}
      .hero-copy{padding:32px 26px}
      .hero-visual{min-height:270px;grid-row:1}
      h1{font-size:32px}
      main section{padding:40px 0}
      .feature-row{grid-template-columns:1fr;gap:22px}
      .feature-image{height:260px}
      .metrics{grid-template-columns:repeat(2,1fr)}
      .metric:nth-child(2){border-right:0}
      .metric:nth-child(-n+2){border-bottom:1px solid var(--line)}
      .news-list{grid-template-columns:repeat(2,1fr)}
      .split-band{grid-template-columns:1fr}
      .assurance{grid-template-columns:1fr}
      .footer-grid{grid-template-columns:1fr 1fr}
      .footer-brand-col{grid-column:1/-1}
    }
    @media(max-width:520px){
      .container{width:calc(100% - 24px)}
      .brand{font-size:13px;gap:8px}
      .brand-mark{width:32px;height:32px}
      .hero-copy{padding:25px 20px}
      h1{font-size:28px}
      .hero-sub{font-size:15px}
      .hero-stats{gap:14px}
      .hero-stats b{font-size:15px}
      .section-head{align-items:flex-start;flex-direction:column;gap:8px}
      .section-head h2{font-size:22px}
      .grid-4,.editorial,.news-list,.ranking,.qa-list{grid-template-columns:1fr}
      .editorial-item{grid-template-columns:84px 1fr}
      .news-image{height:180px}
      .split-points{grid-template-columns:1fr}
      .split-point{padding:12px}
      .metric{padding:16px}
      .metric strong{font-size:21px}
      .footer-grid{gap:22px 14px}
    }