:root{
      --bg:#f4f9ff;
      --white:#ffffff;
      --primary:#0f3b68;
      --secondary:#1f6fb2;
      --accent:#69b7ff;
      --text:#17324d;
      --muted:#5f7791;
      --border:#dce9f5;
      --soft:#eaf4fd;
      --soft2:#f7fbff;
      --shadow:0 14px 38px rgba(20,60,110,.08);
      --radius-lg:24px;
      --radius-md:18px;
      --radius-sm:12px;
      --max:1180px;
    }

    *{
      box-sizing:border-box;
    }

    html{
      scroll-behavior:smooth;
    }

    body{
      margin:0;
      font-family:Arial, Helvetica, sans-serif;
      background:linear-gradient(180deg,#f6fbff 0%,#eef6fd 100%);
      color:var(--text);
      line-height:1.72;
    }

    a{
      color:var(--secondary);
      text-decoration:none;
    }

    a:hover{
      text-decoration:underline;
    }

    img{
      display:block;
      max-width:100%;
      width:100%;
      height:auto;
      border:0;
    }

    .container{
      width:min(var(--max), calc(100% - 32px));
      margin:0 auto;
    }

    .hero{
      position:relative;
      overflow:hidden;
      padding:68px 0 34px;
      background:
        radial-gradient(circle at top right, rgba(105,183,255,.20), transparent 30%),
        radial-gradient(circle at left center, rgba(31,111,178,.12), transparent 28%),
        linear-gradient(180deg,#f8fcff 0%,#edf6fe 100%);
      border-bottom:1px solid #e2edf8;
    }

    .hero-grid{
      display:grid;
      grid-template-columns:1.12fr .88fr;
      gap:34px;
      align-items:center;
    }

    .eyebrow{
      display:inline-block;
      padding:8px 14px;
      border-radius:999px;
      background:var(--soft);
      border:1px solid #d4e6f7;
      color:var(--secondary);
      font-size:13px;
      font-weight:700;
      letter-spacing:.3px;
      text-transform:uppercase;
      margin-bottom:18px;
    }

    h1,h2,h3{
      color:var(--primary);
      line-height:1.2;
      margin:0 0 16px;
    }

    h1{
      font-size:clamp(2rem,4vw,3.35rem);
      letter-spacing:-.02em;
    }

    h2{
      font-size:clamp(1.5rem,2.5vw,2.15rem);
    }

    h3{
      font-size:1.2rem;
    }

    .hero p{
      font-size:1.05rem;
      color:var(--muted);
      max-width:760px;
      margin:0 0 22px;
    }

    .meta{
      display:flex;
      flex-wrap:wrap;
      gap:12px;
      margin:18px 0 26px;
      color:var(--muted);
      font-size:14px;
    }

    .meta span{
      background:rgba(255,255,255,.7);
      border:1px solid #dfeaf6;
      padding:8px 12px;
      border-radius:999px;
    }

    .cta-row{
      display:flex;
      flex-wrap:wrap;
      gap:14px;
      margin-top:10px;
    }

    .btn{
      display:inline-flex;
      align-items:center;
      justify-content:center;
      min-height:48px;
      padding:0 20px;
      border-radius:999px;
      font-weight:700;
      transition:.2s ease;
      border:1px solid transparent;
    }

    .btn-primary{
      background:linear-gradient(135deg,var(--secondary),#4b9ce6);
      color:#fff;
      box-shadow:0 10px 24px rgba(31,111,178,.20);
    }

    .btn-primary:hover{
      transform:translateY(-1px);
      text-decoration:none;
    }

    .btn-secondary{
      background:#fff;
      color:var(--secondary);
      border-color:#cfe2f3;
    }

    .btn-secondary:hover{
      background:#f7fbff;
      text-decoration:none;
    }

    .hero-card,
    .card{
      background:var(--white);
      border:1px solid var(--border);
      border-radius:var(--radius-lg);
      box-shadow:var(--shadow);
    }

    .hero-card{
      padding:18px;
    }

    .hero-media{
      overflow:hidden;
      border-radius:20px;
      border:1px solid #d8e8f6;
      background:#edf6ff;
    }

    /* 修正重点：不再强制固定比例，不再 cover 裁切 */
    .hero-media img{
      width:100%;
      height:auto;
      object-fit:contain;
      aspect-ratio:auto;
    }

    .img-caption{
      padding:12px 14px;
      font-size:13px;
      color:var(--muted);
      background:#f8fbff;
      border-top:1px solid #dfeaf6;
      word-break:break-word;
    }

    .content-wrap{
      padding:42px 0 70px;
    }

    .content-grid{
      display:grid;
      grid-template-columns:minmax(0, 1fr) 320px;
      gap:28px;
      align-items:start;
    }

    .article{
      min-width:0;
    }

    .card{
      padding:30px;
      margin-bottom:24px;
    }

    .article p{
      margin:0 0 18px;
      color:#26405a;
    }

    .article ul,
    .article ol{
      margin:0 0 18px 20px;
      padding:0;
      color:#26405a;
    }

    .article li{
      margin-bottom:10px;
    }

    .highlight{
      background:linear-gradient(180deg,#fafdff 0%,#eef7ff 100%);
      border:1px solid #d9eaf7;
      border-radius:18px;
      padding:22px;
      margin:24px 0;
    }

    .two-col{
      display:grid;
      grid-template-columns:repeat(2,minmax(0,1fr));
      gap:18px;
      margin-top:18px;
    }

    .mini-box{
      background:var(--soft2);
      border:1px solid #dfeef9;
      border-radius:16px;
      padding:18px;
    }

    .mini-box h3{
      margin-bottom:10px;
      font-size:1.02rem;
    }

    .article-image{
      margin:24px 0;
      overflow:hidden;
      border-radius:20px;
      border:1px solid #dceaf6;
      background:#f6fbff;
    }

    /* 修正重点：正文图片不再 16:9 强行裁切 */
    .article-image img{
      width:100%;
      height:auto;
      object-fit:contain;
      aspect-ratio:auto;
      background:#fff;
    }

    .article-image .img-caption{
      padding:14px 16px;
    }

    .table-wrap{
      overflow-x:auto;
      margin:20px 0;
      border-radius:18px;
      border:1px solid #d9e8f5;
    }

    table{
      width:100%;
      border-collapse:collapse;
      min-width:720px;
      background:#fff;
    }

    th,td{
      padding:16px 14px;
      border-bottom:1px solid #e6f0f7;
      text-align:left;
      vertical-align:top;
      font-size:15px;
    }

    th{
      background:#eff7ff;
      color:var(--primary);
      font-size:14px;
      text-transform:uppercase;
      letter-spacing:.04em;
    }

    .note{
      font-size:14px;
      color:var(--muted);
      margin-top:12px;
    }

    .sidebar{
      position:sticky;
      top:20px;
    }

    .toc ul{
      list-style:none;
      margin:0;
      padding:0;
    }

    .toc li{
      margin-bottom:10px;
    }

    .toc a{
      display:block;
      padding:10px 12px;
      border-radius:12px;
      color:var(--text);
      background:#f7fbff;
      border:1px solid #e0edf8;
      font-size:14px;
    }

    .toc a:hover{
      background:#eef7ff;
      text-decoration:none;
    }

    .sidebar .cta-box{
      background:linear-gradient(180deg,#f8fcff 0%,#edf6ff 100%);
    }

    .faq-item{
      border-top:1px solid #e5eef7;
      padding:18px 0;
    }

    .faq-item:first-child{
      border-top:none;
      padding-top:0;
    }

    .faq-item h3{
      font-size:1.05rem;
      margin-bottom:8px;
    }

    .conclusion{
      background:linear-gradient(180deg,#f7fbff 0%,#edf6ff 100%);
    }

    .author-box{
      display:flex;
      gap:16px;
      align-items:flex-start;
      background:#f8fbff;
      border:1px solid #dfebf6;
      border-radius:18px;
      padding:18px;
      margin-top:20px;
    }

    .author-icon{
      width:56px;
      height:56px;
      border-radius:50%;
      background:linear-gradient(135deg,#9fd0ff,#dff1ff);
      display:flex;
      align-items:center;
      justify-content:center;
      font-weight:700;
      color:var(--primary);
      flex:0 0 56px;
    }

    @media (max-width: 980px){
      .hero-grid,
      .content-grid{
        grid-template-columns:1fr;
      }

      .sidebar{
        position:static;
      }
    }

    @media (max-width: 720px){
      .card{
        padding:22px;
      }

      .two-col{
        grid-template-columns:1fr;
      }

      .meta{
        gap:10px;
      }

      .hero{
        padding-top:50px;
      }
    }