:root {
    --primary: #c9601a;
    --primary-dark: #a54c10;
    --primary-light: #fdf1e7;
    --accent: #f2a65a;
    --text: #3a2c22;
    --muted: #7a6a5d;
    --border: #ecd9c8;
    --bg: #fffaf5;
    --white: #ffffff;
  }

  * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }

  html {
    scroll-behavior: smooth;
  }

  body {
    font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.85;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
  }

  .site-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: var(--white);
    text-align: center;
    padding: 56px 20px 64px;
    position: relative;
    overflow: hidden;
  }

  .site-header::before,
  .site-header::after {
    content: "";
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
  }

  .site-header::before {
    width: 280px;
    height: 280px;
    top: -120px;
    left: -80px;
  }

  .site-header::after {
    width: 220px;
    height: 220px;
    bottom: -110px;
    right: -60px;
  }

  .site-header .inner {
    position: relative;
    z-index: 1;
    max-width: 960px;
    margin: 0 auto;
  }

  h1 {
    font-size: 2rem;
    font-weight: 700;
    line-height: 1.4;
    letter-spacing: 0.04em;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  }

  main {
    max-width: 960px;
    margin: -32px auto 0;
    padding: 0 20px 56px;
    position: relative;
    z-index: 2;
  }

  article {
    background: var(--white);
    border-radius: 14px;
    padding: 44px 48px;
    box-shadow: 0 10px 30px rgba(201, 96, 26, 0.12);
    border-top: 5px solid var(--primary);
    overflow-wrap: break-word;
    word-wrap: break-word;
  }

  article h2 {
    font-size: 1.5rem;
    color: var(--primary);
    margin: 2em 0 0.8em;
    padding: 0.2em 0 0.4em 0.8em;
    border-left: 6px solid var(--primary);
    border-bottom: 1px solid var(--border);
    line-height: 1.5;
  }

  article h3 {
    font-size: 1.25rem;
    color: var(--primary-dark);
    margin: 1.8em 0 0.7em;
    padding-bottom: 0.3em;
    border-bottom: 2px dotted var(--accent);
  }

  article h4,
  article h5,
  article h6 {
    font-size: 1.05rem;
    color: var(--primary-dark);
    margin: 1.5em 0 0.5em;
  }

  article > :first-child {
    margin-top: 0;
  }

  article p {
    margin-bottom: 1.2em;
  }

  article ul,
  article ol {
    margin: 0 0 1.2em 1.6em;
  }

  article li {
    margin-bottom: 0.4em;
  }

  article a {
    color: var(--primary);
    text-decoration: underline;
  }

  article a:hover {
    color: var(--primary-dark);
  }

  article img {
    max-width: 100%;
    height: auto;
  }

  article table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1.4em;
    display: block;
    overflow-x: auto;
  }

  article th,
  article td {
    border: 1px solid var(--border);
    padding: 10px 14px;
    text-align: left;
  }

  article th {
    background: var(--primary-light);
    color: var(--primary-dark);
  }

  .transition {
    margin-top: 32px;
    background: var(--primary-light);
    border: 1px solid var(--border);
    border-left: 6px solid var(--primary);
    border-radius: 12px;
    padding: 28px 32px;
    overflow-wrap: break-word;
    word-wrap: break-word;
  }

  .transition p {
    margin-bottom: 1em;
  }

  .transition p:last-child {
    margin-bottom: 0;
  }

  .links-section {
    margin-top: 32px;
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 36px 40px;
    box-shadow: 0 6px 20px rgba(201, 96, 26, 0.08);
    overflow: hidden;
  }

  .links-section h3 {
    font-size: 1.25rem;
    color: var(--primary);
    margin: 1.6em 0 0.8em;
    padding-left: 0.7em;
    border-left: 5px solid var(--primary);
    line-height: 1.5;
  }

  .links-section h3:first-child {
    margin-top: 0;
  }

  .links-section ul {
    list-style: none;
    margin: 0 0 1em;
    padding: 0;
    column-count: 2;
    column-gap: 40px;
  }

  .links-section li {
    break-inside: avoid;
    -webkit-column-break-inside: avoid;
    page-break-inside: avoid;
    padding: 9px 0 9px 1.3em;
    border-bottom: 1px dashed var(--border);
    position: relative;
    overflow-wrap: break-word;
    word-wrap: break-word;
  }

  .links-section li::before {
    content: "▶";
    position: absolute;
    left: 0;
    top: 12px;
    font-size: 0.65em;
    color: var(--accent);
  }

  .links-section a {
    color: var(--text);
    text-decoration: none;
  }

  .links-section a:hover {
    color: var(--primary);
    text-decoration: underline;
  }

  .site-footer {
    background: var(--primary-dark);
    color: var(--white);
    text-align: center;
    padding: 28px 20px;
    font-size: 0.9rem;
  }

  @media (max-width: 768px) {
    body {
      font-size: 15px;
    }

    .site-header {
      padding: 40px 16px 52px;
    }

    h1 {
      font-size: 1.5rem;
    }

    main {
      padding: 0 14px 40px;
      margin-top: -26px;
    }

    article {
      padding: 28px 20px;
    }

    article h2 {
      font-size: 1.25rem;
    }

    article h3 {
      font-size: 1.1rem;
    }

    .transition {
      padding: 22px 18px;
    }

    .links-section {
      padding: 26px 18px;
    }

    .links-section ul {
      column-gap: 24px;
    }
  }

  @media (max-width: 480px) {
    h1 {
      font-size: 1.3rem;
    }

    .links-section ul {
      column-gap: 16px;
    }

    .links-section li {
      font-size: 0.92rem;
    }
  }