:root{
      --bg0:#f6f6f7;
      --bg1:#fbfaf8;
      --card:#ffffff;
      --text:#1f2328;
      --muted:#5c6672;
      --subtle:#7a8796;
      --line:rgba(20,25,30,.10);
      --shadow: 0 10px 30px rgba(20,25,30,.08);
      --shadow2: 0 6px 18px rgba(20,25,30,.08);
      --brand:#1f6feb;
      --brand2:#0ea5e9;
      --accent:#8a6cff;
      --ok:#16a34a;
      --warn:#b45309;
      --radius:16px;
    }
    *{box-sizing:border-box}
    html,body{height:100%}
    body{
      margin:0;
      font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "PingFang SC","Hiragino Sans GB","Microsoft YaHei", sans-serif;
      color:var(--text);
      background:
        radial-gradient(900px 400px at 12% -10%, rgba(31,111,235,.14), transparent 55%),
        radial-gradient(700px 360px at 88% 0%, rgba(138,108,255,.12), transparent 55%),
        linear-gradient(180deg, var(--bg1), var(--bg0));
    }
    a{color:inherit}
    .container{
      width:100%;
      max-width:1120px;
      margin:0 auto;
      padding:0 18px;
    }
    .skip{
      position:absolute;left:-999px;top:0;
      background:#fff; border:1px solid var(--line);
      padding:10px 12px;border-radius:12px;
      z-index:9999;
    }
    .skip:focus{left:12px;top:12px}
    header{
      position:sticky; top:0;
      z-index:50;
      background:rgba(251,250,248,.78);
      backdrop-filter: blur(10px);
      border-bottom:1px solid rgba(20,25,30,.08);
    }
    .nav-wrap{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:12px 0}
    .brand{
      display:flex;align-items:center;gap:10px;min-width:140px;
    }
    .logo{
      width:34px;height:34px;border-radius:12px;
      background:linear-gradient(135deg, rgba(31,111,235,.14), rgba(138,108,255,.14));
      border:1px solid rgba(31,111,235,.22);
      display:grid;place-items:center;
      box-shadow:0 6px 16px rgba(31,111,235,.10);
      font-weight:800;
      letter-spacing:.5px;
    }
    .brand-title{display:flex;flex-direction:column;line-height:1.1}
    .brand-title strong{font-size:14px}
    .brand-title span{font-size:12px;color:var(--muted)}
    nav{display:flex;align-items:center;gap:16px}
    .nav-links{
      display:flex;align-items:center;gap:14px;flex-wrap:wrap;
      justify-content:flex-end;
    }
    .nav-links a{
      text-decoration:none;
      font-size:14px;
      color:var(--muted);
      padding:8px 10px;
      border-radius:12px;
      border:1px solid transparent;
      transition: background .2s ease, border-color .2s ease, color .2s ease, transform .2s ease;
      white-space:nowrap;
    }
    .nav-links a:hover{
      background:rgba(31,111,235,.06);
      border-color:rgba(31,111,235,.18);
      color:#1c3f73;
      transform: translateY(-1px);
    }
    .nav-cta{
      display:flex;align-items:center;gap:10px;flex-wrap:nowrap;
    }
    .btn{
      appearance:none; border:1px solid transparent;
      display:inline-flex; align-items:center; justify-content:center;
      gap:10px;
      padding:10px 14px;
      border-radius:14px;
      text-decoration:none;
      cursor:pointer;
      font-weight:700;
      font-size:14px;
      transition: transform .2s ease, box-shadow .2s ease, background .2s ease, border-color .2s ease, color .2s ease;
      user-select:none;
      white-space:nowrap;
    }
    .btn-primary{
      background:linear-gradient(135deg, var(--brand), var(--brand2));
      color:#fff;
      box-shadow: 0 10px 22px rgba(31,111,235,.18);
    }
    .btn-primary:hover{transform: translateY(-1px); box-shadow: 0 14px 28px rgba(31,111,235,.22)}
    .btn-ghost{
      background:rgba(255,255,255,.7);
      border-color: rgba(20,25,30,.10);
      color:var(--text);
    }
    .btn-ghost:hover{transform: translateY(-1px); border-color: rgba(31,111,235,.25); box-shadow: 0 10px 22px rgba(20,25,30,.08)}
    .burger{
      display:none;
      width:44px;height:44px;
      border-radius:14px;
      border:1px solid rgba(20,25,30,.12);
      background:rgba(255,255,255,.65);
      align-items:center;justify-content:center;
      cursor:pointer;
    }
    .burger span{
      width:18px;height:2px;background:var(--text);
      display:block;position:relative;
    }
    .burger span::before,.burger span::after{
      content:"";position:absolute;left:0;width:18px;height:2px;background:var(--text);
      transition: transform .2s ease, top .2s ease, opacity .2s ease;
    }
    .burger span::before{top:-6px}
    .burger span::after{top:6px}
    .burger[aria-expanded="true"] span{background:transparent}
    .burger[aria-expanded="true"] span::before{top:0;transform: rotate(45deg)}
    .burger[aria-expanded="true"] span::after{top:0;transform: rotate(-45deg)}
    .mobile-panel{
      display:none;
      padding:10px 0 14px;
    }
    .mobile-panel .mobile-links{
      display:flex; flex-direction:column; gap:8px;
      background:rgba(255,255,255,.78);
      border:1px solid rgba(20,25,30,.08);
      border-radius:18px;
      padding:12px;
    }
    .mobile-panel a{
      text-decoration:none;
      padding:10px 12px;
      border-radius:14px;
      border:1px solid rgba(20,25,30,.06);
      background:rgba(251,250,248,.5);
      color:var(--text);
      font-weight:650;
    }
    .mobile-panel a span{display:block;font-weight:500;color:var(--muted);font-size:12px;margin-top:2px}
    main{padding:22px 0 0}
    .hero{
      margin-top:10px;
      position:relative;
      overflow:hidden;
      border-radius:26px;
      border:1px solid rgba(20,25,30,.08);
      background:
        radial-gradient(800px 300px at 15% 10%, rgba(31,111,235,.16), transparent 55%),
        radial-gradient(700px 320px at 85% 0%, rgba(138,108,255,.13), transparent 55%),
        linear-gradient(180deg, rgba(255,255,255,.75), rgba(255,255,255,.52));
      box-shadow: var(--shadow);
    }
    .hero-inner{
      display:grid;
      grid-template-columns: 1.2fr .9fr;
      gap:18px;
      padding:26px;
      align-items:start;
    }
    .kicker{
      display:inline-flex;align-items:center;gap:10px;
      padding:7px 10px;border-radius:999px;
      border:1px solid rgba(31,111,235,.20);
      background:rgba(31,111,235,.06);
      color:#163a70;
      font-weight:700;
      font-size:13px;
    }
    .dot{
      width:8px;height:8px;border-radius:50%;
      background:linear-gradient(135deg, var(--brand), var(--brand2));
      box-shadow:0 0 0 4px rgba(31,111,235,.14);
    }
    h1{
      margin:14px 0 10px;
      font-size:34px;
      letter-spacing:-.6px;
      line-height:1.2;
    }
    .lead{
      margin:0;
      color:var(--muted);
      font-size:15.5px;
      line-height:1.75;
      max-width:62ch;
    }
    .hero-actions{
      display:flex; gap:12px; flex-wrap:wrap;
      margin-top:18px;
      align-items:center;
    }
    .meta-row{
      display:flex; gap:10px; flex-wrap:wrap;
      margin-top:18px;
    }
    .pill{
      display:flex;align-items:center;gap:9px;
      padding:10px 12px;border-radius:16px;
      border:1px solid rgba(20,25,30,.08);
      background:rgba(255,255,255,.72);
      box-shadow: 0 8px 18px rgba(20,25,30,.06);
    }
    .pill svg{flex:0 0 auto}
    .pill strong{font-size:14px}
    .pill span{font-size:12.5px;color:var(--muted);display:block;margin-top:2px}
    .side-card{
      border-radius:22px;
      border:1px solid rgba(20,25,30,.08);
      background:rgba(255,255,255,.70);
      box-shadow: 0 10px 24px rgba(20,25,30,.06);
      padding:16px;
    }
    .side-title{
      display:flex;align-items:center;justify-content:space-between;gap:12px;
      margin-bottom:10px;
    }
    .side-title h2{
      margin:0;
      font-size:16px;
      letter-spacing:-.2px;
    }
    .badge{
      padding:8px 10px;border-radius:999px;
      border:1px solid rgba(138,108,255,.22);
      background:rgba(138,108,255,.08);
      color:#4b2bb7;
      font-weight:800;
      font-size:12.5px;
      white-space:nowrap;
    }
    .quick-list{
      display:grid;
      gap:10px;
      margin:0;
      padding:0;
      list-style:none;
    }
    .quick-item{
      display:flex; gap:12px;
      align-items:flex-start;
      padding:10px 12px;
      border-radius:16px;
      background:rgba(251,250,248,.55);
      border:1px solid rgba(20,25,30,.06);
      transition: transform .2s ease, border-color .2s ease, background .2s ease;
    }
    .quick-item:hover{
      transform: translateY(-2px);
      border-color: rgba(31,111,235,.20);
      background:rgba(255,255,255,.75);
    }
    .qi-icon{
      width:34px;height:34px;border-radius:14px;
      display:grid;place-items:center;
      background:rgba(31,111,235,.10);
      border:1px solid rgba(31,111,235,.18);
      flex:0 0 auto;
    }
    .quick-item strong{font-size:14px}
    .quick-item span{display:block;color:var(--muted);font-size:12.5px;line-height:1.5;margin-top:3px}
    .section{
      margin-top:18px;
      padding:16px 0;
    }
    .section-header{
      display:flex;align-items:flex-end;justify-content:space-between;gap:12px;
      margin-bottom:12px;
    }
    .section-header h2{
      margin:0;
      font-size:20px;
      letter-spacing:-.3px;
    }
    .section-header p{
      margin:0;
      color:var(--muted);
      font-size:13.5px;
      line-height:1.6;
      max-width:50ch;
    }
    .card{
      background:var(--card);
      border:1px solid rgba(20,25,30,.08);
      border-radius:22px;
      box-shadow: 0 10px 26px rgba(20,25,30,.06);
    }
    .toc{
      padding:16px;
      overflow:hidden;
      position:relative;
      background:
        radial-gradient(700px 240px at 10% 10%, rgba(31,111,235,.10), transparent 50%),
        linear-gradient(180deg, rgba(255,255,255,.92), rgba(255,255,255,.76));
    }
    .toc-grid{
      display:grid;
      grid-template-columns: 1fr 1fr;
      gap:12px 14px;
      align-items:start;
    }
    .toc-item{
      display:flex; gap:10px; align-items:flex-start;
      padding:11px 12px;
      border-radius:18px;
      border:1px solid rgba(20,25,30,.06);
      background:rgba(251,250,248,.55);
      transition: transform .2s ease, border-color .2s ease, background .2s ease;
    }
    .toc-item:hover{
      transform: translateY(-2px);
      border-color: rgba(31,111,235,.18);
      background:#fff;
    }
    .toc-num{
      width:26px;height:26px;border-radius:10px;
      display:grid;place-items:center;
      background:rgba(31,111,235,.10);
      border:1px solid rgba(31,111,235,.18);
      color:#0b3a84;
      font-weight:900;
      font-size:13px;
      flex:0 0 auto;
    }
    .toc-item a{
      text-decoration:none;
      color:var(--text);
      font-weight:750;
      font-size:14px;
      line-height:1.3;
    }
    .toc-item small{display:block;color:var(--muted);font-weight:600;margin-top:4px;font-size:12px;line-height:1.3}
    .grid-2{
      display:grid;
      grid-template-columns: 1fr 1fr;
      gap:14px;
    }
    .content-card{padding:16px}
    .content-card h3{margin:0 0 8px;font-size:16px;letter-spacing:-.2px}
    .content-card p{margin:0;color:var(--muted);line-height:1.75;font-size:14.5px}
    .steps{
      padding:16px;
    }
    .steps-wrap{display:grid;grid-template-columns: 1fr; gap:12px}
    .step{
      display:grid;grid-template-columns: 56px 1fr;
      gap:12px;
      padding:12px 12px;
      border-radius:20px;
      border:1px solid rgba(20,25,30,.07);
      background:rgba(251,250,248,.55);
      transition: transform .2s ease, border-color .2s ease, background .2s ease;
    }
    .step:hover{
      transform: translateY(-2px);
      border-color: rgba(31,111,235,.18);
      background:#fff;
    }
    .step .n{
      width:56px;height:56px;border-radius:20px;
      display:grid;place-items:center;
      background:linear-gradient(135deg, rgba(31,111,235,.14), rgba(138,108,255,.12));
      border:1px solid rgba(31,111,235,.20);
      font-weight:950;
      color:#0e2f66;
      box-shadow: 0 10px 18px rgba(31,111,235,.10);
    }
    .step strong{font-size:15px;letter-spacing:-.2px}
    .step ul{margin:8px 0 0;padding-left:18px;color:var(--muted);font-size:14px;line-height:1.7}
    .step li{margin:4px 0}
    .case-card{
      padding:16px;
    }
    .case-top{
      display:flex; align-items:flex-start; justify-content:space-between; gap:12px; flex-wrap:wrap;
      margin-bottom:10px;
    }
    .case-top h3{margin:0;font-size:16px}
    .tag{
      display:inline-flex;align-items:center;gap:8px;
      padding:8px 10px;border-radius:999px;
      background:rgba(22,163,74,.08);
      border:1px solid rgba(22,163,74,.18);
      color:#0f5a2b;
      font-weight:900;
      font-size:12.5px;
    }
    .tag .t-dot{width:8px;height:8px;border-radius:50%;background:var(--ok);box-shadow:0 0 0 4px rgba(22,163,74,.12)}
    .kv{
      display:grid; grid-template-columns: 1fr 1fr;
      gap:12px;
      margin-top:10px;
    }
    .kv .box{
      padding:12px;border-radius:18px;
      border:1px solid rgba(20,25,30,.07);
      background:rgba(251,250,248,.55);
    }
    .kv .box strong{display:block;font-size:13.5px}
    .kv .box span{display:block;color:var(--muted);font-size:13.5px;line-height:1.6;margin-top:6px}
    .faq{
      padding:10px 16px 16px;
    }
    details{
      border-top:1px solid rgba(20,25,30,.08);
      padding:12px 0;
    }
    details:first-of-type{border-top:none}
    summary{
      cursor:pointer;
      list-style:none;
      display:flex; align-items:center; justify-content:space-between; gap:12px;
      font-weight:850;
      font-size:15px;
      color:var(--text);
    }
    summary::-webkit-details-marker{display:none}
    .chev{
      width:34px;height:34px;border-radius:14px;
      border:1px solid rgba(20,25,30,.10);
      background:rgba(255,255,255,.75);
      display:grid;place-items:center;
      flex:0 0 auto;
      transition: transform .2s ease, background .2s ease, border-color .2s ease;
    }
    details[open] .chev{
      transform: rotate(180deg);
      background:rgba(31,111,235,.06);
      border-color: rgba(31,111,235,.22);
    }
    .faq p{
      margin:10px 0 0;
      color:var(--muted);
      font-size:14.5px;
      line-height:1.75;
    }
    .tips{
      padding:16px;
      display:grid;
      grid-template-columns: 1fr 1fr;
      gap:12px;
      align-items:start;
    }
    .tip{
      border-radius:20px;
      border:1px solid rgba(20,25,30,.07);
      background:rgba(251,250,248,.55);
      padding:12px 12px;
    }
    .tip h3{margin:0;font-size:15px}
    .tip ul{margin:10px 0 0;padding-left:18px;color:var(--muted);font-size:14px;line-height:1.7}
    .tip li{margin:4px 0}
    .cta-band{
      padding:16px;
      background:
        radial-gradient(900px 240px at 10% 0%, rgba(31,111,235,.14), transparent 55%),
        radial-gradient(800px 240px at 90% 20%, rgba(138,108,255,.12), transparent 55%),
        linear-gradient(180deg, rgba(255,255,255,.85), rgba(255,255,255,.60));
    }
    .cta-inner{
      display:flex; align-items:center; justify-content:space-between; gap:14px; flex-wrap:wrap;
    }
    .cta-inner h2{
      margin:0;
      font-size:20px;
      letter-spacing:-.3px;
    }
    .cta-inner p{margin:6px 0 0;color:var(--muted);line-height:1.65;font-size:14.5px;max-width:62ch}
    footer{
      margin-top:12px;
      border-top:1px solid rgba(20,25,30,.08);
      background: #f8f7f3;
      color:var(--text);
      padding:18px 0 22px;
    }
    .footer-inner{
      display:grid;
      grid-template-columns: 1.1fr .9fr;
      gap:14px;
      align-items:start;
    }
    .f-card{
      background:#fff;
      border:1px solid rgba(20,25,30,.08);
      border-radius:22px;
      padding:14px;
      box-shadow: 0 10px 22px rgba(20,25,30,.05);
    }
    .f-title{margin:0 0 8px;font-size:15.5px;letter-spacing:-.2px}
    .f-row{
      display:flex; gap:10px; flex-wrap:wrap; align-items:center;
      margin-top:10px;
    }
    .f-links{
      display:flex;flex-direction:column;gap:8px;
      margin-top:10px;
    }
    .f-links a{
      text-decoration:none;
      padding:10px 12px;
      border-radius:16px;
      border:1px solid rgba(20,25,30,.08);
      background:rgba(251,250,248,.65);
      color:var(--text);
      font-weight:700;
    }
    .f-links a span{
      display:block;color:var(--muted);font-weight:600;font-size:12.5px;margin-top:3px;line-height:1.35
    }
    .copyright{
      margin-top:12px;
      color:var(--muted);
      font-size:12.8px;
      line-height:1.6;
      display:flex;
      justify-content:space-between;
      gap:10px;
      flex-wrap:wrap;
    }
    .img-strip{
      display:grid;
      grid-template-columns: repeat(3, 1fr);
      gap:10px;
      margin-top:12px;
    }
    .img-item{
      border-radius:18px;
      border:1px solid rgba(20,25,30,.08);
      background:rgba(255,255,255,.7);
      overflow:hidden;
      box-shadow: 0 10px 18px rgba(20,25,30,.05);
    }
    .img-item img{
      width:100%;
      height:auto;
      display:block;
      object-fit:contain;
      aspect-ratio: 1 / 1;
      background:#fff;
    }
    .img-item .alt{
      padding:10px 10px 12px;
      color:var(--muted);
      font-size:12.5px;
      line-height:1.4;
    }
    .brand-inline{
      display:flex; align-items:center; gap:10px;
      color:var(--muted);
      font-size:13.5px;
      line-height:1.6;
    }
    .toast{
      position:fixed;
      left:50%; bottom:18px;
      transform:translateX(-50%);
      background:rgba(255,255,255,.92);
      border:1px solid rgba(20,25,30,.10);
      border-radius:18px;
      padding:12px 14px;
      box-shadow: 0 18px 50px rgba(20,25,30,.15);
      z-index:200;
      display:none;
      max-width:92vw;
    }
    .toast.show{display:flex;gap:12px;align-items:flex-start}
    .toast .ico{
      width:38px;height:38px;border-radius:16px;
      background:rgba(31,111,235,.10);
      border:1px solid rgba(31,111,235,.18);
      display:grid;place-items:center;
      flex:0 0 auto;
    }
    .toast strong{display:block;font-size:14.5px}
    .toast span{display:block;color:var(--muted);font-size:12.8px;margin-top:3px;line-height:1.4}
    .fade-up{
      opacity:0; transform: translateY(10px);
      transition: opacity .45s ease, transform .45s ease;
    }
    .fade-up.in{opacity:1;transform: translateY(0)}
    @media (max-width: 980px){
      .hero-inner{grid-template-columns: 1fr; padding:18px}
      h1{font-size:28px}
      .toc-grid{grid-template-columns: 1fr}
      .grid-2{grid-template-columns: 1fr}
      .tips{grid-template-columns: 1fr}
      .kv{grid-template-columns: 1fr}
      .img-strip{grid-template-columns: 1fr}
      .footer-inner{grid-template-columns: 1fr}
    }
    @media (max-width: 840px){
      nav{display:none}
      .burger{display:flex}
      .mobile-panel{display:block}
    }
    @media (prefers-reduced-motion: reduce){
      .fade-up{transition:none}
      .btn,.nav-links a,.quick-item,.toc-item,.step{transition:none}
    }