:root {
      --bg: #f2f6f9;
      --surface: #ffffff;
      --ink: #13212e;
      --muted: #516072;
      --line: #d8e0e7;
      --brand: #0d5f8b;
      --brand-soft: #e7f3fa;
      --ok: #0f7a4f;
      --warn: #8a6a02;
      --radius: 18px;
      --shadow: 0 10px 30px rgba(10, 40, 60, 0.08);
      --max: 1160px;
    }

    * { box-sizing: border-box; }
    html, body { margin: 0; padding: 0; }
    body {
      font-family: "Pretendard", "Noto Sans KR", "Apple SD Gothic Neo", sans-serif;
      color: var(--ink);
      background:
        radial-gradient(1200px 500px at 10% -10%, #dceff9 0%, transparent 70%),
        radial-gradient(900px 400px at 100% -5%, #e8f5ee 0%, transparent 70%),
        var(--bg);
      line-height: 1.72;
    }

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

    .hero {
      padding: 52px 0 18px;
    }

    .hero-card {
      background: linear-gradient(160deg, #ffffff 0%, #f7fbff 55%, #f3faf6 100%);
      border: 1px solid var(--line);
      border-radius: calc(var(--radius) + 4px);
      box-shadow: var(--shadow);
      padding: 34px;
    }

    h1, h2, h3 { line-height: 1.35; margin: 0 0 12px; }
    h1 { font-size: clamp(30px, 4vw, 42px); letter-spacing: -0.02em; }
    h2 { font-size: clamp(24px, 3.2vw, 31px); margin-top: 32px; }
    h3 { font-size: clamp(18px, 2.2vw, 23px); margin-top: 22px; }
    p { margin: 0 0 14px; color: var(--ink); }
    .lead { font-size: clamp(17px, 2.1vw, 20px); color: #233547; }
    .muted { color: var(--muted); }
    .hero-points {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      list-style: none;
      padding: 0;
      margin: 14px 0 14px;
    }
    .hero-points li {
      border: 1px solid #c7dce8;
      background: #f4fbff;
      color: #244055;
      border-radius: 999px;
      padding: 7px 11px;
      font-size: 13px;
      font-weight: 700;
    }
    .toc {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin: 10px 0 16px;
    }
    .toc a {
      display: inline-block;
      text-decoration: none;
      font-size: 13px;
      font-weight: 700;
      color: #0b4f73;
      background: #eaf5fc;
      border: 1px solid #c4dfef;
      border-radius: 999px;
      padding: 6px 10px;
    }
    .toc a:hover { background: #dff0fb; }

    .grid {
      display: grid;
      grid-template-columns: 1.15fr .85fr;
      gap: 18px;
      margin-top: 20px;
    }

    .card {
      background: var(--surface);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      padding: 20px;
    }
    .section-title {
      margin: 0 0 14px;
      font-size: 18px;
      color: #163549;
    }

    .tabs { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 16px; }
    .tab-btn {
      border: 1px solid var(--line);
      background: #fff;
      border-radius: 999px;
      padding: 10px 14px;
      font-size: 14px;
      font-weight: 700;
      color: #244055;
      cursor: pointer;
    }
    .tab-btn.active {
      background: var(--brand-soft);
      border-color: #9fc8df;
      color: #0b4f73;
    }

    .tab-pane { display: none; }
    .tab-pane.active { display: block; }

    .form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
    .field { margin-bottom: 10px; }
    label { display: block; font-size: 13px; font-weight: 700; margin-bottom: 6px; color: #2a4254; }
    input {
      width: 100%;
      border: 1px solid #c9d5e0;
      border-radius: 12px;
      padding: 12px;
      font-size: 15px;
      background: #fff;
    }
    input:focus { outline: 2px solid #b2daf0; border-color: #7bb7da; }

    .actions { display: flex; gap: 10px; margin-top: 8px; }
    button.calc {
      flex: 1;
      border: 0;
      background: var(--brand);
      color: #fff;
      border-radius: 12px;
      padding: 12px;
      font-weight: 800;
      cursor: pointer;
      font-size: 15px;
    }

    .result {
      margin-top: 12px;
      border: 1px solid #bdd7e8;
      background: #f5fbff;
      border-radius: 12px;
      padding: 14px;
    }
    .result strong { font-size: 20px; display: block; margin-bottom: 6px; color: #084f75; }
    .interpretation { font-size: 14px; color: #244055; }

    .info-list {
      margin: 0;
      padding-left: 18px;
      color: #334e63;
      font-size: 14px;
    }

    .content {
      margin: 18px 0 52px;
    }

    .content .card { padding: 28px; }
    .content ul { padding-left: 20px; margin: 0 0 14px; }

    .faq-item {
      border: 1px solid var(--line);
      border-radius: 12px;
      padding: 14px;
      margin-bottom: 10px;
      background: #fcfeff;
    }
    .faq-q { font-weight: 800; margin-bottom: 6px; }
    .related-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 12px;
      margin-top: 14px;
    }
    .related-card {
      display: block;
      text-decoration: none;
      border: 1px solid #c9d5e0;
      border-radius: 14px;
      background: linear-gradient(180deg, #ffffff 0%, #f8fcff 100%);
      padding: 16px;
      color: var(--ink);
      box-shadow: 0 8px 18px rgba(10, 40, 60, 0.05);
    }
    .related-card strong {
      display: block;
      margin-bottom: 6px;
      font-size: 16px;
      color: #0b4f73;
    }
    .related-card span {
      display: block;
      color: var(--muted);
      font-size: 14px;
      line-height: 1.55;
    }
    .related-card:hover {
      border-color: #9fc8df;
      transform: translateY(-1px);
    }

    .badge {
      display: inline-block;
      padding: 6px 10px;
      border-radius: 999px;
      background: #ecf8f0;
      color: var(--ok);
      border: 1px solid #bfe5ce;
      font-size: 12px;
      font-weight: 700;
      margin-right: 8px;
      margin-bottom: 8px;
    }

    footer {
      color: #4b6275;
      text-align: center;
      font-size: 13px;
      padding: 14px 0 30px;
    }

    @media (max-width: 940px) {
      .grid { grid-template-columns: 1fr; }
      .form-row { grid-template-columns: 1fr; }
      .hero-card, .content .card { padding: 18px; }
      .hero-points { gap: 8px; }
      .related-grid { grid-template-columns: 1fr; }
    }