:root{
      --bg0:#f6f7fb;
      --bg1:#eef2ff;
      --card:#ffffff;
      --ink:#101827;
      --muted:#4b5563;
      --muted2:#6b7280;
      --line:rgba(16,24,39,.12);
      --shadow: 0 12px 30px rgba(16,24,39,.08);
      --shadow2: 0 8px 18px rgba(16,24,39,.10);
      --brand1:#0b2a4a; /* 黛蓝深邃 */
      --brand2:#1d4f8a;
      --brand3:#2b74c7;
      --accent:#2f6eea;
      --good:#0f766e;
      --warn:#b45309;
      --radius:18px;
      --radius2:14px;
      --radius3:12px;
      --container: 1120px;
      --pad: 18px;
      --focus: 0 0 0 4px rgba(47,110,234,.18);
    }

    *{box-sizing:border-box}
    html,body{height:100%}
    body{
      margin:0;
      font-family: -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",Arial, sans-serif;
      color:var(--ink);
      background:
        radial-gradient(1200px 600px at 15% -10%, rgba(43,116,199,.14), transparent 60%),
        radial-gradient(900px 520px at 90% 0%, rgba(29,79,138,.16), transparent 58%),
        linear-gradient(180deg, var(--bg1), var(--bg0) 40%, #f7f8fc);
    }

    a{color:var(--brand2); text-decoration:none}
    a:hover{ text-decoration: underline; }

    .container{
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 var(--pad);
    }

    .skip{
      position:absolute;
      left:-9999px;
      top:auto;
      width:1px;
      height:1px;
      overflow:hidden;
    }
    .skip:focus{
      left:16px; top:16px;
      width:auto; height:auto;
      padding:10px 12px;
      background:#fff;
      border:1px solid var(--line);
      border-radius:12px;
      z-index:1000;
      box-shadow: var(--shadow2);
      outline:none;
    }

    header{
      position: sticky;
      top: 0;
      z-index: 50;
      backdrop-filter: blur(10px);
      background: rgba(246,247,251,.72);
      border-bottom: 1px solid rgba(16,24,39,.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: 180px;
    }
    .logo{
      width:34px;
      height:34px;
      border-radius: 12px;
      background: linear-gradient(135deg, var(--brand1), var(--brand2));
      color:#fff;
      display:grid;
      place-items:center;
      font-weight:800;
      letter-spacing:.02em;
      box-shadow: 0 10px 20px rgba(11,42,74,.20);
      user-select:none;
    }
    .brand-title{
      display:flex;
      flex-direction:column;
      line-height:1.1;
    }
    .brand-title strong{
      font-size:14px;
      letter-spacing:.02em;
    }
    .brand-title span{
      font-size:12px;
      color:var(--muted2);
      margin-top:4px;
    }

    .nav-right{
      display:flex;
      align-items:center;
      gap:10px;
      justify-content:flex-end;
    }

    .nav-links{
      display:none;
      align-items:center;
      gap:18px;
      flex-wrap:wrap;
      justify-content:flex-end;
    }
    .nav-links a{
      color: rgba(16,24,39,.86);
      font-size:13px;
      padding:8px 10px;
      border-radius: 12px;
      border:1px solid transparent;
      white-space:nowrap;
    }
    .nav-links a:hover{
      background: rgba(29,79,138,.06);
      border-color: rgba(29,79,138,.14);
      text-decoration:none;
    }

    .nav-cta{
      display:flex;
      align-items:center;
      gap:10px;
    }

    .btn{
      display:inline-flex;
      align-items:center;
      justify-content:center;
      gap:10px;
      padding: 10px 14px;
      border-radius: 14px;
      border: 1px solid rgba(16,24,39,.12);
      background: rgba(255,255,255,.78);
      color: var(--ink);
      font-weight: 650;
      font-size: 13px;
      cursor:pointer;
      box-shadow: 0 8px 18px rgba(16,24,39,.06);
      transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease, background .15s ease;
      user-select:none;
    }
    .btn:hover{
      transform: translateY(-1px);
      box-shadow: 0 12px 24px rgba(16,24,39,.10);
      border-color: rgba(29,79,138,.25);
      text-decoration:none;
    }
    .btn:active{ transform: translateY(0px); }
    .btn:focus{ outline:none; box-shadow: var(--focus), 0 12px 24px rgba(16,24,39,.10); }

    .btn-primary{
      border-color: rgba(29,79,138,.20);
      background: linear-gradient(135deg, rgba(11,42,74,.96), rgba(29,79,138,.96));
      color:#fff;
      box-shadow: 0 14px 30px rgba(11,42,74,.18);
    }
    .btn-primary:hover{
      box-shadow: 0 18px 36px rgba(11,42,74,.22);
      border-color: rgba(43,116,199,.35);
      text-decoration:none;
    }

    .burger{
      width:42px; height:42px;
      border-radius:14px;
      border: 1px solid rgba(16,24,39,.12);
      background: rgba(255,255,255,.78);
      display:grid;
      place-items:center;
      cursor:pointer;
      transition: transform .15s ease, border-color .15s ease, background .15s ease;
      box-shadow: 0 8px 18px rgba(16,24,39,.06);
    }
    .burger:hover{
      transform: translateY(-1px);
      border-color: rgba(29,79,138,.25);
      background: rgba(255,255,255,.92);
    }
    .burger:focus{ outline:none; box-shadow: var(--focus), 0 8px 18px rgba(16,24,39,.06); }
    .burger svg{ display:block }

    .mobile-panel{
      display:block;
      max-height:0;
      overflow:hidden;
      transition: max-height .28s ease;
      border-top: 1px solid rgba(16,24,39,.08);
    }
    .mobile-panel.open{ max-height: 420px; }
    .mobile-links{
      padding: 10px 0 14px;
      display:flex;
      flex-direction:column;
      gap: 6px;
    }
    .mobile-links a{
      padding: 12px 12px;
      border-radius: 14px;
      border: 1px solid rgba(16,24,39,.10);
      background: rgba(255,255,255,.70);
      font-weight: 650;
      font-size: 13px;
      color: rgba(16,24,39,.90);
      text-decoration:none;
    }
    .mobile-links a:active{ transform: translateY(1px); }

    main{ padding: 18px 0 26px; }

    .hero{
      padding: 22px 0 10px;
    }

    .hero-grid{
      display:grid;
      grid-template-columns: 1.25fr .85fr;
      gap: 16px;
      align-items: stretch;
    }

    .hero-card{
      border-radius: var(--radius);
      background:
        radial-gradient(900px 360px at 10% 0%, rgba(47,110,234,.22), transparent 55%),
        radial-gradient(700px 340px at 95% 15%, rgba(29,79,138,.18), transparent 55%),
        linear-gradient(180deg, rgba(255,255,255,.85), rgba(255,255,255,.70));
      border: 1px solid rgba(16,24,39,.10);
      box-shadow: var(--shadow);
      padding: 18px 18px 16px;
      position: relative;
      overflow:hidden;
    }

    .hero-card::after{
      content:"";
      position:absolute;
      right:-120px;
      top:-120px;
      width: 260px;
      height: 260px;
      border-radius: 50%;
      background: radial-gradient(circle at 30% 30%, rgba(47,110,234,.26), transparent 60%);
      filter: blur(0px);
      pointer-events:none;
    }

    .kicker{
      display:flex;
      align-items:center;
      gap:10px;
      color: rgba(11,42,74,.92);
      font-weight: 750;
      letter-spacing:.02em;
      font-size: 13px;
    }
    .kicker .dot{
      width:10px; height:10px;
      border-radius: 999px;
      background: linear-gradient(135deg, var(--brand2), var(--brand3));
      box-shadow: 0 10px 18px rgba(29,79,138,.22);
    }

    h1{
      margin: 10px 0 10px;
      font-size: 28px;
      line-height: 1.18;
      letter-spacing: -0.02em;
    }

    .lead{
      margin: 0;
      color: rgba(16,24,39,.82);
      font-size: 14.5px;
      line-height: 1.75;
      max-width: 64ch;
    }

    .hero-actions{
      margin-top: 14px;
      display:flex;
      gap: 10px;
      flex-wrap:wrap;
      align-items:center;
    }

    .meta-strip{
      display:flex;
      gap: 10px;
      flex-wrap:wrap;
      margin-top: 14px;
      padding-top: 12px;
      border-top: 1px dashed rgba(16,24,39,.14);
    }

    .meta-pill{
      display:flex;
      align-items:center;
      gap:10px;
      padding: 10px 12px;
      border-radius: 16px;
      border: 1px solid rgba(16,24,39,.10);
      background: rgba(255,255,255,.65);
      min-width: 190px;
    }
    .meta-icon{
      width:34px; height:34px;
      border-radius: 14px;
      background: rgba(29,79,138,.10);
      display:grid;
      place-items:center;
      border:1px solid rgba(29,79,138,.14);
      color: var(--brand2);
      flex: 0 0 auto;
    }
    .meta-pill strong{
      font-size: 13px;
      letter-spacing:.01em;
    }
    .meta-pill span{
      display:block;
      margin-top:4px;
      font-size: 12px;
      color: var(--muted2);
      line-height: 1.3;
    }

    .hero-side{
      border-radius: var(--radius);
      background: rgba(255,255,255,.78);
      border: 1px solid rgba(16,24,39,.10);
      box-shadow: var(--shadow2);
      padding: 16px;
      display:flex;
      flex-direction:column;
      gap: 12px;
      overflow:hidden;
      position: relative;
    }
    .hero-side::before{
      content:"";
      position:absolute;
      left:-80px;
      bottom:-120px;
      width: 240px;
      height: 240px;
      border-radius: 50%;
      background: radial-gradient(circle at 30% 30%, rgba(29,79,138,.20), transparent 62%);
      pointer-events:none;
    }

    .side-title{
      display:flex;
      align-items:center;
      justify-content:space-between;
      gap: 10px;
      position: relative;
    }
    .side-title h2{
      margin:0;
      font-size: 15px;
      letter-spacing:.01em;
    }
    .badge{
      font-size: 12px;
      font-weight: 750;
      color: rgba(11,42,74,.92);
      background: rgba(29,79,138,.10);
      border: 1px solid rgba(29,79,138,.18);
      padding: 7px 10px;
      border-radius: 999px;
      white-space:nowrap;
    }

    .steps{
      list-style:none;
      padding:0;
      margin:0;
      display:flex;
      flex-direction:column;
      gap:10px;
      position: relative;
    }
    .step{
      display:flex;
      gap: 12px;
      align-items:flex-start;
      padding: 12px;
      border-radius: 16px;
      border: 1px solid rgba(16,24,39,.10);
      background: rgba(255,255,255,.62);
      transition: transform .15s ease, border-color .15s ease, background .15s ease;
    }
    .step:hover{
      transform: translateY(-1px);
      border-color: rgba(29,79,138,.25);
      background: rgba(255,255,255,.78);
    }
    .num{
      width:30px; height:30px;
      border-radius: 12px;
      background: linear-gradient(135deg, rgba(11,42,74,.95), rgba(29,79,138,.95));
      color:#fff;
      display:grid;
      place-items:center;
      font-weight: 800;
      font-size: 12px;
      flex:0 0 auto;
      box-shadow: 0 10px 18px rgba(11,42,74,.18);
    }
    .step strong{
      display:block;
      font-size: 13px;
      margin-top:1px;
    }
    .step span{
      display:block;
      margin-top:4px;
      color: var(--muted2);
      font-size: 12.5px;
      line-height: 1.55;
    }

    .section{
      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: 18px;
      letter-spacing: -0.01em;
    }
    .section-header p{
      margin:0;
      color: var(--muted2);
      font-size: 13px;
      line-height: 1.6;
      max-width: 56ch;
    }

    .grid-2{
      display:grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
      align-items:stretch;
    }
    .grid-3{
      display:grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 12px;
    }

    .card{
      border-radius: var(--radius2);
      background: rgba(255,255,255,.82);
      border: 1px solid rgba(16,24,39,.10);
      box-shadow: 0 10px 24px rgba(16,24,39,.06);
      padding: 14px;
      overflow:hidden;
      position: relative;
    }

    .card h3{
      margin: 0 0 8px;
      font-size: 14.5px;
      letter-spacing: -0.01em;
    }
    .card p{
      margin: 0;
      color: rgba(16,24,39,.78);
      font-size: 13.5px;
      line-height: 1.75;
    }

    .list{
      margin: 10px 0 0;
      padding: 0;
      list-style: none;
      display:flex;
      flex-direction:column;
      gap: 8px;
    }
    .list li{
      display:flex;
      gap: 10px;
      align-items:flex-start;
      color: rgba(16,24,39,.82);
      font-size: 13.2px;
      line-height: 1.55;
    }
    .check{
      width:18px; height:18px;
      border-radius: 7px;
      border: 1px solid rgba(29,79,138,.22);
      background: rgba(29,79,138,.10);
      color: var(--brand2);
      display:grid;
      place-items:center;
      flex:0 0 auto;
      margin-top: 1px;
    }

    .toc{
      display:flex;
      flex-wrap:wrap;
      gap: 10px;
      margin-top: 10px;
    }
    .toc a{
      display:inline-flex;
      align-items:center;
      gap: 10px;
      padding: 10px 12px;
      border-radius: 16px;
      border: 1px solid rgba(16,24,39,.10);
      background: rgba(255,255,255,.68);
      color: rgba(16,24,39,.86);
      font-weight: 650;
      font-size: 13px;
      transition: transform .15s ease, border-color .15s ease, background .15s ease;
      text-decoration:none;
      animation: riseIn .45s ease both;
    }
    .toc a:hover{
      transform: translateY(-1px);
      border-color: rgba(29,79,138,.26);
      background: rgba(255,255,255,.84);
      text-decoration:none;
    }
    .toc a:focus{ outline:none; box-shadow: var(--focus); }

    @keyframes riseIn{
      from{ opacity:0; transform: translateY(6px); }
      to{ opacity:1; transform: translateY(0); }
    }

    .article{
      background: rgba(255,255,255,.78);
      border: 1px solid rgba(16,24,39,.10);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      padding: 16px;
      overflow:hidden;
    }

    .anchors{
      scroll-margin-top: 90px;
    }

    .article-grid{
      display:grid;
      grid-template-columns: 1.05fr .95fr;
      gap: 14px;
      align-items:start;
    }

    .prose h2{
      margin: 12px 0 8px;
      font-size: 17px;
      letter-spacing:-0.01em;
    }
    .prose h3{
      margin: 12px 0 8px;
      font-size: 14.5px;
      letter-spacing:-0.01em;
    }
    .prose p{
      margin: 0 0 10px;
      color: rgba(16,24,39,.80);
      font-size: 13.8px;
      line-height: 1.85;
    }

    .callout{
      border-radius: 16px;
      padding: 14px;
      border: 1px solid rgba(29,79,138,.18);
      background:
        linear-gradient(180deg, rgba(29,79,138,.08), rgba(29,79,138,.03));
      position: sticky;
      top: 86px;
    }
    .callout .tag{
      display:inline-flex;
      align-items:center;
      gap:8px;
      font-size: 12px;
      font-weight: 800;
      color: rgba(11,42,74,.95);
      background: rgba(29,79,138,.10);
      border: 1px solid rgba(29,79,138,.18);
      padding: 7px 10px;
      border-radius: 999px;
      margin-bottom: 10px;
    }
    .callout ul{
      margin: 0;
      padding:0;
      list-style:none;
      display:flex;
      flex-direction:column;
      gap: 10px;
    }
    .callout li{
      display:flex;
      gap: 10px;
      align-items:flex-start;
      padding: 10px;
      border-radius: 14px;
      border: 1px solid rgba(16,24,39,.10);
      background: rgba(255,255,255,.62);
    }
    .callout li .ico{
      width:30px; height:30px;
      border-radius: 12px;
      display:grid;
      place-items:center;
      background: rgba(29,79,138,.10);
      border: 1px solid rgba(29,79,138,.16);
      color: var(--brand2);
      flex: 0 0 auto;
    }
    .callout li strong{
      display:block;
      font-size: 13px;
      margin-top: 1px;
    }
    .callout li span{
      display:block;
      margin-top: 4px;
      color: var(--muted2);
      font-size: 12.5px;
      line-height: 1.55;
    }

    .faq{
      display:flex;
      flex-direction:column;
      gap: 10px;
    }
    .faq details{
      border-radius: 16px;
      border: 1px solid rgba(16,24,39,.10);
      background: rgba(255,255,255,.74);
      padding: 12px 12px;
      transition: border-color .15s ease, background .15s ease, transform .15s ease;
    }
    .faq details[open]{
      border-color: rgba(29,79,138,.25);
      background: rgba(255,255,255,.86);
    }
    .faq summary{
      cursor:pointer;
      list-style:none;
      display:flex;
      align-items:flex-start;
      justify-content:space-between;
      gap: 10px;
      font-weight: 800;
      font-size: 13.8px;
      color: rgba(16,24,39,.92);
    }
    .faq summary::-webkit-details-marker{ display:none; }
    .faq .chev{
      flex:0 0 auto;
      width:30px; height:30px;
      border-radius: 12px;
      display:grid;
      place-items:center;
      border: 1px solid rgba(16,24,39,.10);
      background: rgba(255,255,255,.60);
      color: rgba(16,24,39,.82);
      transition: transform .18s ease;
      margin-top: -3px;
    }
    details[open] .chev{ transform: rotate(180deg); }
    .faq .answer{
      margin-top: 10px;
      color: rgba(16,24,39,.80);
      font-size: 13.5px;
      line-height: 1.85;
    }
    .fineprint{
      color: var(--muted2);
      font-size: 12.6px;
      line-height: 1.7;
      margin-top: 10px;
    }

    .footer{
      margin-top: 8px;
      background: linear-gradient(180deg, rgba(11,42,74,.96), rgba(8,30,56,.98));
      color:#e5eaf3;
      border-top: 1px solid rgba(255,255,255,.10);
      padding: 22px 0;
    }
    .footer-grid{
      display:grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
      align-items:start;
    }
    .foot-card{
      border-radius: 18px;
      border: 1px solid rgba(255,255,255,.14);
      background: rgba(255,255,255,.06);
      padding: 14px;
    }
    .foot-card h2{
      margin:0 0 10px;
      font-size: 15px;
      letter-spacing:-0.01em;
      color:#fff;
    }
    .foot-card p{
      margin:0;
      color: rgba(229,234,243,.88);
      font-size: 13.4px;
      line-height: 1.8;
    }
    .foot-links{
      display:flex;
      flex-wrap:wrap;
      gap: 10px;
      margin-top: 10px;
    }
    .foot-links a{
      color: #d7e3ff;
      border: 1px solid rgba(255,255,255,.16);
      background: rgba(255,255,255,.06);
      padding: 9px 10px;
      border-radius: 14px;
      font-weight: 700;
      font-size: 12.8px;
      text-decoration:none;
      transition: transform .15s ease, border-color .15s ease, background .15s ease;
    }
    .foot-links a:hover{
      transform: translateY(-1px);
      border-color: rgba(131,176,255,.32);
      background: rgba(255,255,255,.10);
      text-decoration:none;
    }

    .copyright{
      margin-top: 14px;
      color: rgba(229,234,243,.75);
      font-size: 12.3px;
      line-height: 1.6;
    }

    .gallery{
      margin-top: 12px;
      display:grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 10px;
    }
    .img-frame{
      border-radius: 16px;
      border: 1px solid rgba(16,24,39,.10);
      background: rgba(255,255,255,.60);
      overflow:hidden;
      padding: 10px;
    }
    .img-frame img{
      width:100%;
      height:auto;
      display:block;
      border-radius: 12px;
      object-fit: contain;
      filter: saturate(1.02) contrast(1.02);
      transform: translateZ(0);
      transition: transform .18s ease;
    }
    .img-frame:hover img{ transform: scale(1.02); }

    .sr-only{
      position:absolute;
      width:1px; height:1px;
      padding:0; margin:-1px;
      overflow:hidden;
      clip:rect(0,0,0,0);
      white-space:nowrap;
      border:0;
    }

    @media (max-width: 980px){
      .hero-grid{ grid-template-columns: 1fr; }
      .callout{ position: static; }
      .article-grid{ grid-template-columns: 1fr; }
      .grid-2{ grid-template-columns: 1fr; }
      .grid-3{ grid-template-columns: 1fr; }
      .gallery{ grid-template-columns: repeat(2, 1fr); }
      .footer-grid{ grid-template-columns: 1fr; }
      h1{ font-size: 24px; }
      .nav-links{ display:none; }
    }
    @media (min-width: 981px){
      .nav-links{ display:flex; }
      .burger{ display:none; }
      .mobile-panel{ display:none; }
    }