:root {
      --ink: #06131f;
      --paper: #ffffff;
      --line: #dbe3ea;
      --muted: #4b5563;
      --signal: #0b63ce;
      --font-sans: HelveticaNeue, "Helvetica Neue", Helvetica, Arial,
        "游ゴシック体", YuGothic, "游ゴシック Medium", "Yu Gothic Medium",
        "游ゴシック", "Yu Gothic", "ヒラギノ角ゴ ProN W3", "Hiragino Kaku Gothic ProN",
        "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", "MS ゴシック", "MS Gothic",
        sans-serif;
      --font-mono: "SF Mono", "Fira Code", "Fira Mono", Menlo, Consolas, monospace;
      font-family: var(--font-sans);
      color: var(--ink);
      background: var(--paper);
    }

    * { box-sizing: border-box; }

    html { scroll-behavior: smooth; }

    body {
      margin: 0;
      font-size: 16px;
      line-height: 1.8;
      font-feature-settings: "palt";
      -webkit-font-smoothing: antialiased;
      word-wrap: break-word;
      background: #f8f7f2;
    }

    a { color: inherit; text-decoration: none; }
    img { display: block; max-width: 100%; height: auto; }

    .site-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 18px;
      min-height: 62px;
      padding: 14px clamp(20px, 4vw, 58px) 10px;
      background: #f8f7f2;
      box-shadow: inset 0 -1px 0 rgba(6, 19, 31, 0.08);
    }

    .brand {
      display: inline-flex;
      align-items: center;
      gap: 7px;
    }

    .brand-symbol { width: 40px; }
    .brand-wordmark { width: 96px; }

    main {
      max-width: 820px;
      margin: 0 auto;
      padding: clamp(40px, 7vw, 88px) clamp(20px, 4vw, 40px) clamp(60px, 9vw, 120px);
    }

    .breadcrumb {
      margin-bottom: 18px;
      color: var(--muted);
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 780;
      letter-spacing: 0.06em;
    }

    .breadcrumb a {
      text-decoration: underline;
      text-underline-offset: 3px;
    }

    .breadcrumb a:hover,
    .breadcrumb a:focus-visible {
      color: var(--signal);
      outline: none;
    }

    .section-label {
      margin: 0;
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 780;
      letter-spacing: 0.1em;
      text-transform: uppercase;
    }

    h1 {
      margin: 14px 0 18px;
      font-size: clamp(24px, 3.6vw, 36px);
      font-weight: 820;
      line-height: 1.28;
      letter-spacing: 0.02em;
    }

    .hub-video-feature {
      margin: 0 0 18px;
    }

    .hub-video-frame {
      position: relative;
      aspect-ratio: 16 / 9;
      overflow: hidden;
      border: 1px solid var(--line, #d9dee5);
      border-radius: 8px;
      background: #06131f;
    }

    .hub-video-frame iframe {
      position: absolute;
      inset: 0;
      width: 100%;
      height: 100%;
      border: 0;
    }

    .hub-video-feature figcaption {
      margin-top: 10px;
      font-size: 14px;
      line-height: 1.8;
    }

    .hub-summary {
      margin: 0 0 14px;
      padding: 0;
      list-style: none;
      font-size: 16.5px;
      line-height: 1.9;
    }

    .hub-summary li {
      position: relative;
      padding-left: 16px;
    }

    .hub-summary li::before {
      content: "";
      position: absolute;
      left: 0;
      top: 0.9em;
      width: 7px;
      height: 1px;
      background: var(--signal);
    }

    .hub-note {
      margin: 0 0 44px;
      color: var(--muted);
      font-size: 14px;
      line-height: 1.8;
    }

    h2 {
      margin: 0 0 6px;
      font-size: clamp(19px, 2.3vw, 23px);
      font-weight: 850;
      letter-spacing: 0.015em;
    }

    .section-note {
      margin: 0 0 18px;
      color: var(--muted);
      font-size: 14px;
    }

    section { margin-bottom: clamp(40px, 6vw, 64px); }

    .hub-cards {
      display: grid;
      gap: 12px;
    }

    .hub-card {
      display: grid;
      gap: 6px;
      padding: 22px clamp(18px, 2.4vw, 26px);
      border: 1px solid var(--line);
      background: var(--paper);
      transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
    }

    .hub-card:hover,
    .hub-card:focus-visible {
      border-color: var(--signal);
      transform: translateY(-2px);
      box-shadow: 0 12px 28px -20px rgba(6, 19, 31, 0.6);
      outline: none;
    }

    .hub-card-kicker {
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 800;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    .hub-card-title {
      font-size: 17px;
      font-weight: 830;
      line-height: 1.55;
    }

    .hub-card-note {
      color: var(--muted);
      font-size: 13.5px;
      line-height: 1.75;
    }

    .hub-card.primary {
      border-color: var(--ink);
      background: var(--ink);
      color: var(--paper);
    }

    .hub-card.primary .hub-card-kicker { color: rgba(255, 255, 255, 0.66); }
    .hub-card.primary .hub-card-note { color: rgba(255, 255, 255, 0.74); }

    .hub-card.primary:hover,
    .hub-card.primary:focus-visible { border-color: var(--signal); }

    .video-list {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 14px;
    }

    .video-card {
      display: grid;
      align-content: start;
      gap: 10px;
      border: 1px solid var(--line);
      background: var(--paper);
      transition: border-color 0.18s ease, transform 0.18s ease;
    }

    .video-card:hover,
    .video-card:focus-visible {
      border-color: var(--signal);
      transform: translateY(-2px);
      outline: none;
    }

    .video-card img {
      width: 100%;
      aspect-ratio: 16 / 9;
      object-fit: cover;
      background: #eef2f5;
    }

    .video-card-body {
      display: grid;
      gap: 6px;
      padding: 0 15px 17px;
    }

    .video-card-title {
      font-size: 14px;
      font-weight: 800;
      line-height: 1.6;
    }

    .video-card-meta {
      color: var(--muted);
      font-family: var(--font-mono);
      font-size: 11px;
      letter-spacing: 0.04em;
    }

    .term-list {
      display: flex;
      flex-wrap: wrap;
      gap: 9px;
      padding: 0;
      margin: 0;
      list-style: none;
    }

    .term-list a {
      display: inline-flex;
      padding: 9px 16px;
      border: 1px solid var(--line);
      background: var(--paper);
      font-size: 13.5px;
      font-weight: 760;
      transition: border-color 0.18s ease, color 0.18s ease;
    }

    .term-list a:hover,
    .term-list a:focus-visible {
      border-color: var(--signal);
      color: var(--signal);
      outline: none;
    }

    .faq-item {
      padding: 20px 0;
      border-top: 1px solid var(--line);
    }

    .faq-item:last-of-type { border-bottom: 1px solid var(--line); }

    .faq-item h3 {
      margin: 0 0 8px;
      font-size: 15.5px;
      font-weight: 830;
      line-height: 1.6;
    }

    .faq-item p {
      margin: 0;
      color: var(--muted);
      font-size: 14.5px;
      line-height: 1.85;
    }

    .faq-item p a {
      color: var(--signal);
      text-decoration: underline;
      text-underline-offset: 3px;
    }

    .connect-strip {
      margin-bottom: 0;
      padding: 26px clamp(18px, 2.6vw, 30px);
      border: 1px solid var(--line);
      background: linear-gradient(180deg, rgba(11, 99, 206, 0.05), rgba(11, 99, 206, 0.015));
    }

    .connect-strip h2 { margin-bottom: 16px; }

    .connect-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
    }

    .connect-button {
      display: inline-flex;
      align-items: center;
      padding: 10px 18px;
      border: 1px solid var(--line);
      background: var(--paper);
      font-size: 13.5px;
      font-weight: 780;
      transition: border-color 0.18s ease, color 0.18s ease, transform 0.18s ease;
    }

    .connect-button:hover,
    .connect-button:focus-visible {
      border-color: var(--signal);
      color: var(--signal);
      transform: translateY(-1px);
      outline: none;
    }

    .connect-button.primary {
      border-color: var(--signal);
      background: var(--signal);
      color: #fff;
    }

    .connect-button.primary:hover,
    .connect-button.primary:focus-visible {
      color: #fff;
      filter: brightness(1.08);
    }

    .site-footer {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      gap: 10px 16px;
      padding: 18px clamp(20px, 4vw, 58px);
      background: linear-gradient(180deg, #eef2f5 0%, #f8f7f2 62%);
      box-shadow: inset 0 1px 0 rgba(6, 19, 31, 0.08);
      color: var(--muted);
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 850;
      letter-spacing: 0.04em;
      text-transform: uppercase;
    }

    .site-footer a:hover,
    .site-footer a:focus-visible {
      color: var(--signal);
      outline: none;
    }

    @media (max-width: 760px) {
      .video-list { grid-template-columns: minmax(0, 1fr); }
    }

    @media (max-width: 420px) {
      .connect-actions { flex-direction: column; align-items: stretch; }
      .connect-button { justify-content: center; }
    }

    /* ---- 記事と同じ装飾（色帯の章見出し・番号札・マーカー・囲み） ---- */
    main { max-width: 860px; }

    .hub-hero {
      margin: 0 0 22px;
    }

    .hub-hero img {
      width: 100%;
      aspect-ratio: 16 / 8;
      object-fit: cover;
      border-radius: 8px;
      border: 1px solid var(--line);
    }

    .hub-hero figcaption,
    .hub-figure-source {
      margin-top: 8px;
      color: var(--muted);
      font-size: 12.5px;
      line-height: 1.7;
    }

    .hub-box {
      margin: 0 0 18px;
      padding: 20px clamp(18px, 2.6vw, 28px) 16px;
      border: 2px solid var(--ink);
      border-radius: 8px;
      background: var(--paper);
    }

    .hub-box-title {
      margin: 0 0 10px;
      font-size: 15px;
      font-weight: 850;
      letter-spacing: 0.02em;
    }

    .hub-box .hub-summary { margin-bottom: 0; }

    main p strong,
    main li strong {
      font-weight: 800;
      background: linear-gradient(transparent 62%, rgba(255, 214, 10, 0.55) 62%);
    }

    section > h2 {
      display: flex;
      align-items: center;
      gap: 12px;
      margin: 0 0 10px;
      padding: 12px 16px;
      border-left: 6px solid var(--signal);
      background: rgba(11, 99, 206, 0.07);
      border-radius: 0 6px 6px 0;
    }

    section > h2[data-no]::before {
      content: attr(data-no);
      flex: none;
      display: inline-grid;
      place-items: center;
      width: 34px;
      height: 34px;
      border-radius: 50%;
      background: var(--signal);
      color: #fff;
      font-family: var(--font-mono);
      font-size: 14px;
      font-weight: 800;
    }

    .connect-strip > h2 { background: none; border-left: 0; padding: 0; }

    /* 年表 */
    .plan-timeline {
      position: relative;
      margin: 18px 0 8px;
      padding: 0;
      list-style: none;
      display: grid;
      grid-template-columns: repeat(4, minmax(0, 1fr));
      gap: 12px;
    }

    .plan-timeline::before {
      content: "";
      position: absolute;
      left: 6%;
      right: 6%;
      top: 22px;
      height: 3px;
      background: linear-gradient(90deg, #d93025, var(--signal));
      border-radius: 2px;
    }

    .plan-step {
      position: relative;
      display: grid;
      gap: 6px;
      justify-items: center;
      text-align: center;
    }

    .plan-year {
      position: relative;
      z-index: 1;
      display: inline-grid;
      place-items: center;
      min-width: 88px;
      height: 44px;
      padding: 0 12px;
      border-radius: 22px;
      background: var(--ink);
      color: #fff;
      font-family: var(--font-mono);
      font-size: 15px;
      font-weight: 800;
    }

    .plan-step:last-child .plan-year { background: var(--signal); color: #fff; }
    .plan-year { color: #fff !important; }

    .plan-step strong {
      font-size: 14.5px;
      line-height: 1.55;
      background: none !important;
    }

    .plan-step span {
      color: var(--muted);
      font-size: 12.8px;
      line-height: 1.7;
    }

    .pull-quote {
      margin: 26px 0 8px;
      padding: 18px 4px;
      border-top: 2px solid var(--ink);
      border-bottom: 2px solid var(--ink);
      font-size: clamp(18px, 2.4vw, 22px);
      font-weight: 820;
      line-height: 1.6;
      text-align: center;
    }

    .pull-quote cite {
      display: block;
      margin-top: 6px;
      color: var(--muted);
      font-size: 12.5px;
      font-style: normal;
      font-weight: 600;
    }

    /* 3本の柱 */
    .pillar-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 12px;
      margin: 14px 0 0;
      padding: 0;
      list-style: none;
    }

    .pillar {
      padding: 18px 16px 16px;
      border: 1px solid var(--line);
      border-top: 4px solid var(--signal);
      border-radius: 6px;
      background: var(--paper);
    }

    .pillar-no {
      display: block;
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 800;
      letter-spacing: 0.08em;
    }

    .pillar h3 {
      margin: 4px 0 6px;
      font-size: 16px;
      font-weight: 850;
    }

    .pillar p {
      margin: 0;
      color: var(--muted);
      font-size: 13.5px;
      line-height: 1.8;
    }

    /* よくある質問：1問1答を囲む */
    .faq-item {
      position: relative;
      margin: 0 0 12px;
      padding: 18px 20px 18px 64px;
      border: 1px solid var(--line);
      border-radius: 8px;
      background: var(--paper);
    }

    .faq-item:last-of-type { border-bottom: 1px solid var(--line); }

    .faq-item::before,
    .faq-item::after {
      position: absolute;
      left: 18px;
      display: grid;
      place-items: center;
      width: 32px;
      height: 32px;
      border-radius: 50%;
      font-family: var(--font-mono);
      font-size: 14px;
      font-weight: 800;
    }

    .faq-item::before {
      content: "Q";
      top: 16px;
      background: var(--ink);
      color: #fff;
    }

    .faq-item::after {
      content: "A";
      top: 58px;
      border: 2px solid var(--signal);
      color: var(--signal);
    }

    .faq-item h3 { margin-bottom: 12px; }

    /* 読むカード・関連論考カードに画像 */
    .hub-cards { grid-template-columns: repeat(3, minmax(0, 1fr)); }

    .hub-card { padding: 0; overflow: hidden; border-radius: 8px; }

    .hub-card-thumb {
      width: 100%;
      aspect-ratio: 16 / 8.4;
      object-fit: cover;
      background: #eef2f5;
    }

    .hub-card-text {
      display: grid;
      gap: 6px;
      padding: 16px clamp(16px, 2.2vw, 22px) 20px;
    }

    .related-cards {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 12px;
      margin: 0 0 14px;
      padding: 0;
      list-style: none;
    }

    .related-cards a {
      display: grid;
      height: 100%;
      overflow: hidden;
      border: 1px solid var(--line);
      border-radius: 8px;
      background: var(--paper);
      transition: border-color 0.18s ease, transform 0.18s ease;
    }

    .related-cards a:hover,
    .related-cards a:focus-visible {
      border-color: var(--signal);
      transform: translateY(-2px);
      outline: none;
    }

    .related-cards img {
      width: 100%;
      aspect-ratio: 16 / 8.4;
      object-fit: cover;
      background: #eef2f5;
    }

    .related-cards span {
      padding: 12px 14px 14px;
      font-size: 14px;
      font-weight: 800;
      line-height: 1.6;
    }

    .video-card, .hub-video-frame { border-radius: 8px; overflow: hidden; }

    .term-list a { border-radius: 999px; }

    @media (max-width: 760px) {
      .plan-timeline { grid-template-columns: minmax(0, 1fr); gap: 14px; }
      .plan-timeline::before { left: 43px; right: auto; top: 10px; bottom: 10px; width: 3px; height: auto; background: linear-gradient(180deg, #d93025, var(--signal)); }
      .plan-step { grid-template-columns: 88px minmax(0, 1fr); justify-items: start; text-align: left; column-gap: 14px; }
      .plan-year { grid-row: span 2; min-width: 88px; }
      .pillar-grid, .hub-cards, .related-cards { grid-template-columns: minmax(0, 1fr); }
      .faq-item { padding-left: 58px; }
      .faq-item::before, .faq-item::after { left: 14px; }
    }