:root {
      --navy: #123b59;
      --blue: #176b9e;
      --cyan: #1ca6c9;
      --ice: #edf8fb;
      --pale: #f6fbfd;
      --ink: #203744;
      --muted: #607783;
      --line: #d8e8ee;
      --white: #ffffff;
      --shadow: 0 16px 42px rgba(18, 59, 89, 0.09);
    }

    * {
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      margin: 0;
      background: var(--pale);
      color: var(--ink);
      font-family: Inter, "Segoe UI", Roboto, Arial, sans-serif;
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }

    a {
      color: var(--blue);
      text-decoration-thickness: 1px;
      text-underline-offset: 3px;
    }

    a:hover {
      color: var(--navy);
    }

    .page-shell {
      overflow: hidden;
    }

    .hero {
      position: relative;
      background:
        radial-gradient(circle at 87% 18%, rgba(65, 201, 226, 0.28), transparent 26%),
        linear-gradient(135deg, #0c334e 0%, #176b9e 58%, #22a5c7 100%);
      color: var(--white);
    }

    .hero::after {
      content: "";
      position: absolute;
      inset: auto -8% -85px -8%;
      height: 150px;
      background: var(--pale);
      border-radius: 50% 50% 0 0 / 45% 45% 0 0;
    }

    .hero-inner {
      position: relative;
      z-index: 1;
      max-width: 1180px;
      margin: 0 auto;
      padding: 78px 24px 122px;
    }

    .eyebrow {
      display: inline-flex;
      margin-bottom: 20px;
      padding: 7px 13px;
      border: 1px solid rgba(255, 255, 255, 0.34);
      border-radius: 999px;
      color: #e9fbff;
      font-size: 0.76rem;
      font-weight: 700;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    h1,
    h2,
    h3 {
      color: var(--navy);
      line-height: 1.25;
      margin-top: 0;
    }

    h1 {
      max-width: 920px;
      margin-bottom: 22px;
      color: var(--white);
      font-size: clamp(2.15rem, 5vw, 4.4rem);
      letter-spacing: -0.035em;
    }

    .hero-lead {
      max-width: 790px;
      margin: 0;
      color: #e7f8fc;
      font-size: clamp(1.05rem, 2vw, 1.28rem);
    }

    .hero-meta {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 28px;
    }

    .hero-meta span {
      padding: 8px 13px;
      border-radius: 8px;
      background: rgba(255, 255, 255, 0.13);
      color: #f4fdff;
      font-size: 0.88rem;
    }

    .breadcrumbs {
      max-width: 1180px;
      margin: -58px auto 0;
      padding: 0 24px 34px;
      position: relative;
      z-index: 2;
      color: var(--muted);
      font-size: 0.9rem;
    }

    .breadcrumbs a {
      color: var(--muted);
      text-decoration: none;
    }

    .breadcrumbs span {
      margin: 0 8px;
      color: #98adb7;
    }

    main {
      max-width: 1180px;
      margin: 0 auto;
      padding: 0 24px 70px;
    }

    .answer-box {
      margin-bottom: 34px;
      padding: 28px 30px;
      border: 1px solid #bce5ed;
      border-left: 5px solid var(--cyan);
      border-radius: 16px;
      background: linear-gradient(135deg, #ffffff 0%, #f0fbfd 100%);
      box-shadow: var(--shadow);
    }

    .answer-box h2 {
      margin-bottom: 10px;
      font-size: 1.35rem;
    }

    .answer-box p {
      margin: 0;
    }

    .content-grid {
      display: grid;
      grid-template-columns: minmax(0, 1fr) 310px;
      gap: 34px;
      align-items: start;
    }

    .article-body {
      min-width: 0;
      padding: 38px 42px;
      border: 1px solid var(--line);
      border-radius: 18px;
      background: var(--white);
      box-shadow: var(--shadow);
    }

    .article-body h2 {
      margin: 42px 0 16px;
      padding-top: 10px;
      border-top: 1px solid var(--line);
      font-size: clamp(1.55rem, 3vw, 2.1rem);
    }

    .article-body h2:first-child {
      margin-top: 0;
      padding-top: 0;
      border-top: 0;
    }

    .article-body h3 {
      margin: 25px 0 10px;
      font-size: 1.18rem;
    }

    .article-body p {
      margin: 0 0 17px;
    }

    .article-body ul,
    .article-body ol {
      margin: 12px 0 22px;
      padding-left: 24px;
    }

    .article-body li {
      margin: 8px 0;
    }

    .check-list {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 12px;
      margin: 20px 0 24px;
      padding: 0;
      list-style: none;
    }

    .check-list li {
      position: relative;
      margin: 0;
      padding: 15px 16px 15px 43px;
      border: 1px solid var(--line);
      border-radius: 12px;
      background: var(--pale);
    }

    .check-list li::before {
      content: "✓";
      position: absolute;
      left: 16px;
      top: 13px;
      color: var(--cyan);
      font-size: 1.2rem;
      font-weight: 800;
    }

    .info-table {
      width: 100%;
      border-collapse: collapse;
      margin: 20px 0 25px;
      overflow: hidden;
      border: 1px solid var(--line);
      border-radius: 12px;
      font-size: 0.95rem;
    }

    .info-table th,
    .info-table td {
      padding: 14px 15px;
      border-bottom: 1px solid var(--line);
      text-align: left;
      vertical-align: top;
    }

    .info-table th {
      background: var(--ice);
      color: var(--navy);
      font-weight: 700;
    }

    .info-table tr:last-child td {
      border-bottom: 0;
    }

    .callout {
      margin: 25px 0;
      padding: 22px 24px;
      border-radius: 14px;
      background: #f3f9fb;
      box-shadow: inset 4px 0 0 var(--blue);
    }

    .callout strong {
      color: var(--navy);
    }

    .cta {
      margin-top: 40px;
      padding: 28px;
      border-radius: 16px;
      background: linear-gradient(135deg, #123b59, #176b9e);
      color: var(--white);
    }

    .cta h2 {
      margin-bottom: 10px;
      color: var(--white);
      font-size: 1.6rem;
    }

    .cta p {
      color: #e6f7fb;
    }

    .cta-button {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      margin-top: 7px;
      padding: 12px 18px;
      border-radius: 9px;
      background: var(--white);
      color: var(--navy);
      font-weight: 800;
      text-decoration: none;
    }

    .cta-button:hover {
      background: #e6f8fb;
      color: var(--navy);
    }

    .sidebar {
      position: sticky;
      top: 22px;
      display: grid;
      gap: 18px;
    }

    .side-card {
      padding: 23px;
      border: 1px solid var(--line);
      border-radius: 16px;
      background: var(--white);
      box-shadow: 0 10px 30px rgba(18, 59, 89, 0.06);
    }

    .side-card h2 {
      margin-bottom: 13px;
      font-size: 1.12rem;
    }

    .toc {
      margin: 0;
      padding-left: 19px;
    }

    .toc li {
      margin: 8px 0;
      line-height: 1.45;
    }

    .toc a {
      text-decoration: none;
      font-size: 0.92rem;
    }

    .keyword-list {
      display: flex;
      flex-wrap: wrap;
      gap: 7px;
      margin: 0;
      padding: 0;
      list-style: none;
    }

    .keyword-list li {
      padding: 6px 9px;
      border-radius: 7px;
      background: var(--ice);
      color: var(--blue);
      font-size: 0.78rem;
    }

    .faq-list {
      display: grid;
      gap: 12px;
      margin-top: 20px;
    }

    .faq-list details {
      border: 1px solid var(--line);
      border-radius: 12px;
      background: var(--pale);
    }

    .faq-list summary {
      cursor: pointer;
      padding: 16px 18px;
      color: var(--navy);
      font-weight: 700;
    }

    .faq-list details p {
      margin: 0;
      padding: 0 18px 17px;
    }

    .note {
      color: var(--muted);
      font-size: 0.9rem;
    }

    footer {
      padding: 28px 24px 40px;
      border-top: 1px solid var(--line);
      color: var(--muted);
      text-align: center;
      font-size: 0.88rem;
    }

    @media (max-width: 900px) {
      .content-grid {
        grid-template-columns: 1fr;
      }

      .sidebar {
        position: static;
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }
    }

    @media (max-width: 620px) {
      .hero-inner {
        padding: 52px 18px 110px;
      }

      .breadcrumbs,
      main {
        padding-left: 18px;
        padding-right: 18px;
      }

      .article-body {
        padding: 27px 21px;
      }

      .answer-box {
        padding: 22px 20px;
      }

      .check-list,
      .sidebar {
        grid-template-columns: 1fr;
      }

      .info-table {
        display: block;
        overflow-x: auto;
        white-space: normal;
      }
    }