:root {
      --bg: #111214;
      --panel: #1c1c1f;
      --panel-soft: #222327;
      --line: #313238;
      --text: #f4f4f5;
      --muted: #b4b4bb;
      --accent: #ffcf67;
      --accent-soft: rgba(255, 207, 103, 0.12);
      --code: #15161a;
      --shadow: 0 24px 80px rgba(0, 0, 0, 0.28);
      --radius: 22px;
    }

    * {
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      margin: 0;
      font-family: "Poppins", "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
      background:
        radial-gradient(circle at top left, rgba(255, 207, 103, 0.08), transparent 28%),
        radial-gradient(circle at top right, rgba(84, 120, 255, 0.12), transparent 24%),
        var(--bg);
      color: var(--text);
      line-height: 1.8;
    }

    a {
      color: inherit;
      text-decoration: none;
    }

    .shell {
      width: min(1120px, calc(100% - 32px));
      margin: 32px auto 64px;
    }

    .topbar {
      position: sticky;
      top: 20px;
      z-index: 20;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      padding: 16px 18px;
      margin-bottom: 22px;
      background: rgba(28, 28, 31, 0.92);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: 20px;
      backdrop-filter: blur(16px);
      box-shadow: var(--shadow);
    }

    .topbar-left {
      display: flex;
      align-items: center;
      gap: 14px;
      min-width: 0;
    }

    .back-link {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 10px 14px;
      border: 1px solid var(--line);
      border-radius: 999px;
      color: var(--muted);
      transition: 0.2s ease;
      white-space: nowrap;
    }

    .back-link:hover {
      color: var(--text);
      border-color: rgba(255, 207, 103, 0.35);
      background: var(--accent-soft);
    }

    .topbar-meta {
      min-width: 0;
    }

    .eyebrow {
      margin: 0 0 4px;
      color: var(--accent);
      font-size: 12px;
      font-weight: 600;
      letter-spacing: 0.12em;
      text-transform: uppercase;
    }

    .page-title {
      margin: 0;
      font-size: clamp(20px, 3vw, 28px);
      line-height: 1.2;
    }

    .github-button {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 48px;
      height: 48px;
      flex: 0 0 auto;
      border: 1px solid rgba(255, 207, 103, 0.32);
      border-radius: 14px;
      background: rgba(255, 207, 103, 0.08);
      color: var(--accent);
      cursor: pointer;
      transition: 0.2s ease;
    }

    .github-button:hover {
      transform: translateY(-1px);
      background: rgba(255, 207, 103, 0.14);
      border-color: rgba(255, 207, 103, 0.5);
    }

    .hero {
      padding: 34px;
      background: linear-gradient(160deg, rgba(255, 207, 103, 0.06), rgba(84, 120, 255, 0.08)), var(--panel);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }

    .hero h1 {
      margin: 0 0 14px;
      font-size: clamp(34px, 6vw, 56px);
      line-height: 1.05;
      letter-spacing: -0.03em;
    }

    .hero p {
      margin: 0;
      max-width: 820px;
      color: var(--muted);
      font-size: 16px;
    }

    .chips {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 20px;
    }

    .chip {
      display: inline-flex;
      align-items: center;
      padding: 8px 12px;
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: 999px;
      background: rgba(255, 255, 255, 0.03);
      color: var(--muted);
      font-size: 13px;
    }

    .content-wrap {
      margin-top: 24px;
      padding: 30px;
      background: var(--panel);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }

    .loading,
    .error {
      padding: 22px;
      border-radius: 18px;
      background: var(--panel-soft);
      color: var(--muted);
    }

    .error {
      color: #ffd2d2;
      border: 1px solid rgba(255, 120, 120, 0.25);
    }

    .markdown-body > :first-child {
      margin-top: 0;
    }

    .markdown-body > :last-child {
      margin-bottom: 0;
    }

    .markdown-body h1,
    .markdown-body h2,
    .markdown-body h3,
    .markdown-body h4 {
      line-height: 1.3;
      letter-spacing: -0.02em;
      margin: 1.8em 0 0.7em;
    }

    .markdown-body h1 {
      font-size: 32px;
    }

    .markdown-body h2 {
      padding-top: 0.8em;
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      font-size: 24px;
    }

    .markdown-body h3 {
      font-size: 19px;
    }

    .markdown-body p,
    .markdown-body li,
    .markdown-body td,
    .markdown-body th,
    .markdown-body blockquote {
      color: var(--muted);
      font-size: 15px;
    }

    .markdown-body strong {
      color: var(--text);
    }

    .markdown-body ul,
    .markdown-body ol {
      padding-left: 1.4em;
    }

    .markdown-body li + li {
      margin-top: 0.38em;
    }

    .markdown-body code {
      font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
      font-size: 0.92em;
      color: #ffe39b;
      background: rgba(255, 255, 255, 0.04);
      border-radius: 8px;
      padding: 0.18em 0.45em;
    }

    .markdown-body pre {
      overflow: auto;
      padding: 18px;
      border: 1px solid rgba(255, 255, 255, 0.06);
      border-radius: 16px;
      background: var(--code);
    }

    .markdown-body pre code {
      padding: 0;
      background: transparent;
      color: #d8d8de;
    }

    .markdown-body table {
      width: 100%;
      border-collapse: collapse;
      margin: 1.2em 0;
      overflow: hidden;
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: 16px;
    }

    .markdown-body th,
    .markdown-body td {
      padding: 12px 14px;
      border-bottom: 1px solid rgba(255, 255, 255, 0.06);
      border-right: 1px solid rgba(255, 255, 255, 0.04);
      vertical-align: top;
      text-align: left;
    }

    .markdown-body th {
      color: var(--text);
      background: rgba(255, 255, 255, 0.04);
      font-weight: 600;
    }

    .markdown-body tr:last-child td {
      border-bottom: 0;
    }

    .markdown-body blockquote {
      margin: 1.2em 0;
      padding: 14px 18px;
      border-left: 4px solid rgba(255, 207, 103, 0.6);
      background: rgba(255, 207, 103, 0.06);
      border-radius: 0 14px 14px 0;
    }

    .mermaid {
      position: relative;
      margin: 22px 0;
      overflow: hidden;
      padding: 56px 18px 18px;
      border: 1px solid rgba(255, 255, 255, 0.06);
      border-radius: 16px;
      background: #141519;
    }

    .mermaid svg {
      display: block;
      width: 100% !important;
      max-width: 100% !important;
      height: auto !important;
      margin: 0 auto;
    }

    .diagram-expand {
      position: absolute;
      top: 14px;
      right: 14px;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 8px 12px;
      border: 1px solid rgba(255, 207, 103, 0.28);
      border-radius: 999px;
      background: rgba(255, 207, 103, 0.08);
      color: var(--accent);
      font-size: 12px;
      line-height: 1;
      white-space: nowrap;
      cursor: pointer;
      z-index: 2;
    }

    .diagram-expand:hover {
      background: rgba(255, 207, 103, 0.14);
      border-color: rgba(255, 207, 103, 0.45);
    }

    .diagram-hint {
      margin: -8px 0 14px;
      color: rgba(255, 255, 255, 0.54);
      font-size: 12px;
      text-align: right;
    }

    .overlay {
      position: fixed;
      inset: 0;
      display: none;
      align-items: center;
      justify-content: center;
      padding: 20px;
      background: rgba(0, 0, 0, 0.62);
      z-index: 60;
    }

    .overlay.active {
      display: flex;
    }

    .modal {
      width: min(460px, 100%);
      padding: 26px;
      background: var(--panel);
      border: 1px solid rgba(255, 255, 255, 0.06);
      border-radius: 22px;
      box-shadow: var(--shadow);
    }

    .modal h2 {
      margin: 0 0 12px;
      font-size: 24px;
    }

    .modal p {
      margin: 0;
      color: var(--muted);
    }

    .modal-actions {
      display: flex;
      justify-content: flex-end;
      margin-top: 20px;
    }

    .modal-close {
      padding: 10px 14px;
      border: 1px solid rgba(255, 207, 103, 0.32);
      border-radius: 12px;
      background: rgba(255, 207, 103, 0.08);
      color: var(--accent);
      cursor: pointer;
    }

    .diagram-modal {
      width: min(96vw, 1700px);
      max-height: 92vh;
      padding: 18px;
      background: var(--panel);
      border: 1px solid rgba(255, 255, 255, 0.06);
      border-radius: 24px;
      box-shadow: var(--shadow);
    }

    .diagram-modal-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      margin-bottom: 14px;
    }

    .diagram-modal-title {
      margin: 0;
      font-size: 20px;
    }

    .diagram-modal-body {
      overflow: auto;
      max-height: calc(92vh - 84px);
      padding: 14px;
      border-radius: 18px;
      background: #141519;
      border: 1px solid rgba(255, 255, 255, 0.06);
    }

    .diagram-modal-body svg {
      display: block;
      max-width: none !important;
      height: auto !important;
    }

    .interview-overview {
      display: grid;
      gap: 24px;
      margin-top: 24px;
    }

    .interview-grid {
      display: grid;
      grid-template-columns: repeat(12, minmax(0, 1fr));
      gap: 18px;
    }

    .interview-card,
    .interview-section {
      padding: 26px;
      background: var(--panel);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }

    .interview-card {
      grid-column: span 4;
    }

    .interview-card--wide {
      grid-column: span 12;
    }

    .card-eyebrow {
      margin: 0 0 10px;
      color: var(--accent);
      font-size: 12px;
      font-weight: 600;
      letter-spacing: 0.1em;
      text-transform: uppercase;
    }

    .interview-card h2,
    .section-title {
      margin: 0 0 12px;
      font-size: clamp(24px, 3vw, 34px);
      line-height: 1.18;
      letter-spacing: -0.03em;
    }

    .interview-card p,
    .section-lead,
    .step-card p,
    .principle-card p {
      margin: 0;
      color: var(--muted);
      font-size: 15px;
      line-height: 1.75;
    }

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

    .simple-list li {
      position: relative;
      padding-left: 16px;
      color: var(--muted);
      font-size: 15px;
      line-height: 1.75;
    }

    .simple-list li + li {
      margin-top: 10px;
    }

    .simple-list li::before {
      content: "";
      position: absolute;
      left: 0;
      top: 11px;
      width: 6px;
      height: 6px;
      border-radius: 50%;
      background: var(--accent);
    }

    .step-grid,
    .principle-grid {
      display: grid;
      gap: 16px;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      margin-top: 18px;
    }

    .overview-flow {
      display: grid;
      gap: 16px;
      margin-top: 18px;
    }

    .flow-sources {
      display: grid;
      gap: 16px;
      grid-template-columns: 1.2fr 0.8fr;
    }

    .flow-card,
    .flow-note {
      padding: 20px;
      background: var(--panel-soft);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: 18px;
    }

    .flow-card h3,
    .flow-note h3 {
      margin: 0 0 8px;
      font-size: 18px;
      line-height: 1.4;
    }

    .flow-card p,
    .flow-note p,
    .flow-merge {
      margin: 0;
      color: var(--muted);
      font-size: 15px;
      line-height: 1.75;
    }

    .flow-merge {
      padding: 12px 16px;
      border: 1px dashed rgba(255, 207, 103, 0.28);
      border-radius: 16px;
      background: rgba(255, 207, 103, 0.06);
    }

    .flow-chain {
      display: flex;
      align-items: center;
      gap: 12px;
      overflow-x: auto;
      padding-bottom: 4px;
    }

    .system-diagram {
      display: flex;
      align-items: stretch;
      gap: 12px;
      overflow-x: auto;
      margin-top: 18px;
      padding-bottom: 4px;
    }

    .system-card {
      flex: 0 0 240px;
      padding: 20px;
      background: var(--panel-soft);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: 18px;
    }

    .system-card--accent {
      border-color: rgba(255, 207, 103, 0.28);
      background: rgba(255, 207, 103, 0.08);
    }

    .system-label {
      margin: 0 0 8px;
      color: var(--accent);
      font-size: 12px;
      font-weight: 600;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    .system-card h3 {
      margin: 0 0 10px;
      font-size: 18px;
      line-height: 1.4;
    }

    .system-card p {
      margin: 0;
      color: var(--muted);
      font-size: 14px;
      line-height: 1.7;
    }

    .system-footnotes {
      display: grid;
      gap: 14px;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      margin-top: 14px;
    }

    .flow-item {
      flex: 0 0 auto;
      min-width: 160px;
      padding: 16px 18px;
      background: var(--panel-soft);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: 16px;
      color: var(--text);
      font-size: 15px;
      line-height: 1.6;
      text-align: center;
    }

    .flow-item--accent {
      border-color: rgba(255, 207, 103, 0.28);
      background: rgba(255, 207, 103, 0.08);
    }

    .flow-arrow {
      flex: 0 0 auto;
      color: var(--accent);
      font-size: 22px;
      font-weight: 700;
      line-height: 1;
    }

    .step-card,
    .principle-card {
      padding: 20px;
      background: var(--panel-soft);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: 18px;
    }

    .step-number {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 34px;
      height: 34px;
      margin-bottom: 14px;
      border-radius: 50%;
      background: rgba(255, 207, 103, 0.12);
      color: var(--accent);
      font-weight: 700;
      font-size: 14px;
    }

    .step-card h3,
    .principle-card h3 {
      margin: 0 0 8px;
      font-size: 18px;
      line-height: 1.4;
    }

    .detail-section {
      margin-top: 24px;
    }

    .detail-toggle {
      background: transparent;
      border: 0;
    }

    .detail-toggle > summary {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 14px;
      padding: 22px 26px;
      list-style: none;
      cursor: pointer;
      user-select: none;
      background: var(--panel);
      border: 1px solid rgba(255, 255, 255, 0.05);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }

    .detail-toggle > summary::-webkit-details-marker {
      display: none;
    }

    .detail-label {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .detail-title {
      color: var(--text);
      font-size: 22px;
      font-weight: 600;
      line-height: 1.25;
    }

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

    .detail-status {
      color: var(--accent);
      font-size: 13px;
      white-space: nowrap;
    }

    .detail-body {
      padding-top: 18px;
    }

    .detail-body .content-wrap {
      margin-top: 0;
    }

    @media (max-width: 768px) {
      .shell {
        width: min(100% - 20px, 1120px);
        margin-top: 16px;
      }

      .topbar {
        top: 12px;
        padding: 14px;
      }

      .hero,
      .content-wrap,
      .interview-card,
      .interview-section {
        padding: 20px;
      }

      .topbar-left {
        gap: 10px;
      }

      .back-link span:last-child {
        display: none;
      }

      .markdown-body table {
        display: block;
        overflow-x: auto;
      }

      .diagram-modal {
        width: min(100vw - 16px, 1700px);
        padding: 14px;
      }

      .diagram-modal-body {
        max-height: calc(92vh - 72px);
        padding: 10px;
      }

      .interview-grid {
        grid-template-columns: 1fr;
      }

      .interview-card,
      .interview-card--wide {
        grid-column: auto;
      }

      .step-grid,
      .principle-grid {
        grid-template-columns: 1fr;
      }

      .flow-sources {
        grid-template-columns: 1fr;
      }

      .flow-chain {
        flex-direction: column;
        align-items: stretch;
        overflow-x: visible;
      }

      .system-diagram {
        flex-direction: column;
        overflow-x: visible;
      }

      .system-card {
        flex-basis: auto;
      }

      .system-footnotes {
        grid-template-columns: 1fr;
      }

      .flow-arrow {
        align-self: center;
        transform: rotate(90deg);
      }

      .detail-toggle > summary {
        padding: 18px 20px;
      }

      .detail-title {
        font-size: 20px;
      }

      .detail-status {
        display: none;
      }
    }