:root {
      --ink: #06131f;
      --ink-rgb: 6, 19, 31;
      --paper: #ffffff;
      --page: #f8f7f2;
      --surface: #ffffff;
      --surface-rgb: 255, 255, 255;
      --line: #dbe3ea;
      --muted: #4b5563;
      --signal: #0b63ce;
      --card-gradient:
        radial-gradient(ellipse at 8% 0%, rgba(6, 19, 31, 0.052) 0%, rgba(6, 19, 31, 0.016) 34%, rgba(6, 19, 31, 0) 62%),
        linear-gradient(145deg, #ffffff 0%, #f8f7f2 58%, #e7edf2 100%);
      --card-hover-gradient: linear-gradient(145deg, #f8fbff 0%, #ffffff 58%, #eaf2fb 100%);
      --footer-gradient: linear-gradient(180deg, #eef2f5 0%, #f8f7f2 62%);
      --reveal-ease: cubic-bezier(0.2, 0.84, 0.2, 1);
      --reveal-duration: 0.72s;
      --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);
    }

    html[data-color-mode="light"] { color-scheme: light; }

    html[data-color-mode="dark"] {
      color-scheme: dark;
      --ink: #edf4fa;
      --ink-rgb: 237, 244, 250;
      --page: #07121c;
      --surface: #0d1b28;
      --surface-rgb: 13, 27, 40;
      --line: #2b4154;
      --muted: #afbdc9;
      --signal: #7cbcff;
      --card-gradient:
        radial-gradient(ellipse at 8% 0%, rgba(124, 188, 255, 0.11) 0%, rgba(124, 188, 255, 0.03) 34%, rgba(7, 18, 28, 0) 62%),
        linear-gradient(145deg, #13283a 0%, #0d1b28 58%, #091722 100%);
      --card-hover-gradient: linear-gradient(145deg, #17334a 0%, #102538 58%, #0b1c2a 100%);
      --footer-gradient: linear-gradient(180deg, #0d1b28 0%, #07121c 62%);
      background: var(--page);
    }

    * { box-sizing: border-box; }

    html {
      overflow-x: hidden;
    }

    body {
      margin: 0;
      font-size: 16px;
      line-height: 1.8;
      font-feature-settings: "palt";
      -webkit-font-smoothing: antialiased;
      word-wrap: break-word;
      background: var(--page);
      overflow-x: hidden;
    }

    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: var(--page);
      box-shadow: inset 0 -1px 0 rgba(var(--ink-rgb), 0.08);
    }

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

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

    .back-link {
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 780;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

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

    main {
      width: min(100%, 1160px);
      max-width: 1160px;
      margin: 0 auto;
      padding: clamp(40px, 7vw, 88px) clamp(20px, 4vw, 40px) clamp(60px, 9vw, 120px);
    }

    .breadcrumb {
      margin: 0;
      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;
    }

    .research-toolbar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      margin-bottom: 18px;
    }

    .color-mode-toggle {
      display: inline-flex;
      flex: 0 0 auto;
      align-items: center;
      gap: 8px;
      min-height: 36px;
      padding: 7px 11px;
      border: 1px solid rgba(var(--ink-rgb), 0.4);
      background: var(--surface);
      color: var(--ink);
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 820;
      letter-spacing: 0.06em;
      text-transform: uppercase;
      cursor: pointer;
    }

    .color-mode-toggle:hover,
    .color-mode-toggle:focus-visible {
      border-color: var(--signal);
      color: var(--signal);
      outline: 2px solid var(--signal);
      outline-offset: 2px;
    }

    .color-mode-toggle-icon {
      position: relative;
      width: 12px;
      height: 12px;
      border: 1px solid currentColor;
      border-radius: 50%;
    }

    .color-mode-toggle-icon::after {
      position: absolute;
      inset: 2px 2px 2px 5px;
      border-radius: 0 999px 999px 0;
      background: currentColor;
      content: "";
    }

    .section-label {
      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 28px;
      font-size: clamp(28px, 4vw, 40px);
      font-weight: 820;
      line-height: 1.2;
      letter-spacing: 0.02em;
    }

    /* 記事がこのページの本体。特設・翻訳・動画は冒頭の入口タイルに留める（design.md） */
    .research-doors {
      display: grid;
      grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr) minmax(0, 0.8fr);
      gap: 14px;
      margin: 0 0 36px;
    }

    .ai2040-door { display: grid; align-content: start; }

    .ai2040-project {
      position: relative;
      display: grid;
      grid-template-columns: minmax(0, 1fr);
      gap: 16px;
      align-content: space-between;
      padding: clamp(18px, 2vw, 24px);
      overflow: hidden;
      border: 1px solid var(--ink);
      background:
        radial-gradient(circle at 88% 34%, rgba(11, 99, 206, 0.72), transparent 31%),
        linear-gradient(135deg, #02080d 0%, #071928 72%, #0b63ce 170%);
      color: #f8f7f2;
      text-decoration: none;
    }

    .ai2040-project::after {
      content: "2040";
      position: absolute;
      right: clamp(18px, 4vw, 48px);
      top: 50%;
      color: rgba(248, 247, 242, 0.08);
      font-family: var(--font-mono);
      font-size: clamp(84px, 10vw, 140px);
      font-weight: 850;
      letter-spacing: -0.12em;
      line-height: 0.8;
      transform: translateY(-50%);
      pointer-events: none;
    }

    .ai2040-project-copy {
      position: relative;
      z-index: 1;
      display: grid;
      gap: 12px;
      max-width: 720px;
    }

    .ai2040-project-kicker {
      margin: 0;
      color: #7cbcff;
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 820;
      letter-spacing: 0.12em;
      text-transform: uppercase;
    }

    .ai2040-project h2 {
      margin: 0;
      color: #f8f7f2;
      font-size: clamp(24px, 2.4vw, 32px);
      line-height: 1.12;
    }

    .ai2040-project p:last-child {
      max-width: 620px;
      margin: 0;
      color: rgba(248, 247, 242, 0.76);
      font-size: 14px;
      line-height: 1.7;
    }

    .ai2040-project-cta {
      position: relative;
      z-index: 1;
      white-space: nowrap;
      color: #f8f7f2;
      font-size: 13px;
      font-weight: 820;
      letter-spacing: 0.04em;
    }

    .ai2040-project-note {
      margin: 10px 0 0;
      color: var(--muted);
      font-size: 13px;
      font-weight: 600;
      letter-spacing: 0.02em;
    }

    .ai2040-project-note a {
      padding-bottom: 3px;
      border-bottom: 1px solid rgba(var(--ink-rgb), 0.28);
      transition: color 0.18s ease, border-color 0.18s ease;
    }

    .ai2040-project-note a:hover,
    .ai2040-project-note a:focus-visible {
      color: var(--signal);
      border-color: var(--signal);
    }

    .ai2040-project:hover,
    .ai2040-project:focus-visible {
      border-color: #7cbcff;
      outline: none;
    }

    .ai2040-project:hover .ai2040-project-cta,
    .ai2040-project:focus-visible .ai2040-project-cta {
      color: #7cbcff;
    }

    .translation-archive,
    .video-door {
      color: var(--ink);
      text-decoration: none;
      display: grid;
      gap: 16px;
      align-content: space-between;
      padding: clamp(18px, 2vw, 24px);
      border: 1px solid rgba(var(--ink-rgb), 0.42);
      background: var(--surface);
    }

    .translation-archive { border-left: 5px solid var(--signal); }

    .video-door { gap: 10px; }

    .video-door-foot {
      display: flex;
      flex-wrap: wrap;
      align-items: baseline;
      justify-content: space-between;
      gap: 4px 12px;
    }

    .video-door-link {
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 820;
      white-space: nowrap;
    }

    .video-door:focus-visible,
    .translation-archive:focus-visible {
      outline: 3px solid var(--signal);
      outline-offset: 4px;
    }

    .translation-archive-copy {
      display: grid;
      gap: 8px;
    }

    .video-door-thumb {
      position: relative;
      display: block;
      overflow: hidden;
    }

    /* サムネイルだけでは動画と分かりにくいので、/videos と同じ再生マークを重ねる */
    .video-door-thumb::after {
      content: "▶";
      position: absolute;
      left: 50%;
      top: 50%;
      display: grid;
      place-items: center;
      width: 64px;
      height: 44px;
      padding-left: 3px;
      background: rgba(6, 19, 31, 0.86);
      color: #fff;
      font-size: 16px;
      transform: translate(-50%, -50%);
      transition: background 0.2s ease;
    }

    .video-door:hover .video-door-thumb::after,
    .video-door:focus-visible .video-door-thumb::after {
      background: var(--signal);
    }

    .video-door-thumb img {
      display: block;
      width: 100%;
      aspect-ratio: 16 / 9;
      height: auto;
      object-fit: cover;
      transition: transform 0.32s ease;
    }

    .video-door:hover .video-door-thumb img,
    .video-door:focus-visible .video-door-thumb img {
      transform: scale(1.035);
    }

    .translation-archive-kicker,
    .video-door-kicker {
      margin: 0;
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 820;
      letter-spacing: 0.12em;
      text-transform: uppercase;
    }

    .translation-archive h2,
    .video-door h2 {
      margin: 0;
      font-size: clamp(18px, 1.7vw, 23px);
      line-height: 1.3;
    }

    .translation-archive-copy > p:last-child {
      margin: 0;
      color: var(--muted);
      font-size: 14px;
      line-height: 1.7;
    }

    .translation-archive-link {
      display: inline-flex;
      align-items: center;
      justify-content: space-between;
      gap: 10px;
      justify-self: start;
      min-height: 44px;
      padding: 9px 14px;
      border: 1px solid var(--ink);
      background: var(--ink);
      color: var(--paper);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 820;
      letter-spacing: 0.03em;
      white-space: nowrap;
    }

    .translation-archive:hover .translation-archive-link,
    .translation-archive:focus-visible .translation-archive-link {
      border-color: var(--signal);
      background: var(--signal);
      color: var(--paper);
      outline: none;
    }

    @media (max-width: 1020px) {
      .research-doors p:not([class]) { display: none; }
    }

    @media (max-width: 700px) {
      .research-doors {
        grid-template-columns: 1fr;
        gap: 10px;
        margin-bottom: 28px;
      }

      .ai2040-project,
      .translation-archive,
      .video-door {
        gap: 10px;
        padding: 14px 16px;
      }

      .ai2040-project::after { font-size: 84px; }

      /* 行の高さを他の入口に揃えるため、サムネイルを右へ寄せて横並びを保つ */
      .video-door {
        grid-template-columns: minmax(0, 1fr) 132px;
        align-items: center;
      }

      .video-door-thumb { grid-column: 2; grid-row: 1 / span 2; }
      .video-door-thumb::after { width: 40px; height: 28px; font-size: 12px; }

      .translation-archive-link {
        min-height: 0;
        padding: 0;
        border: 0;
        background: none;
        color: var(--signal);
        white-space: normal;
      }
    }

    .news-digest {
      display: grid;
      gap: 12px;
      margin: 0 0 32px;
    }

    .news-digest-lead {
      flex-basis: 100%;
      margin: 0;
      color: var(--muted);
      font-size: 14px;
      line-height: 1.7;
    }

    .news-digest-body {
      display: grid;
      grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
      gap: 14px;
    }

    .news-digest-body:has(> :only-child) { grid-template-columns: 1fr; }

    .news-digest-latest {
      display: grid;
      grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
      gap: 18px;
      padding: clamp(14px, 1.6vw, 20px);
      border: 1px solid rgba(var(--ink-rgb), 0.42);
      border-left: 5px solid var(--signal);
      background: var(--surface);
      color: var(--ink);
      text-decoration: none;
    }

    .news-digest-body:has(> :only-child) .news-digest-latest { grid-template-columns: 240px minmax(0, 1fr); }

    .news-digest-latest:focus-visible,
    .news-digest-past a:focus-visible {
      outline: 3px solid var(--signal);
      outline-offset: 4px;
    }

    .news-digest-thumb { display: block; overflow: hidden; align-self: start; }

    .news-digest-thumb img {
      display: block;
      width: 100%;
      aspect-ratio: 16 / 9;
      height: auto;
      object-fit: cover;
      transition: transform 0.32s ease;
    }

    .news-digest-latest:hover .news-digest-thumb img { transform: scale(1.035); }

    .news-digest-copy { display: grid; gap: 10px; align-content: start; }

    .news-digest-meta {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 8px 12px;
      color: var(--muted);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 720;
    }

    .news-digest-badge {
      padding: 2px 8px;
      background: var(--signal);
      color: var(--paper);
      font-size: 11px;
      font-weight: 820;
      letter-spacing: 0.06em;
    }

    .news-digest-headline {
      font-size: clamp(18px, 1.7vw, 22px);
      font-weight: 820;
      line-height: 1.4;
    }

    .news-digest-latest:hover .news-digest-headline { color: var(--signal); }

    .news-digest-topics {
      margin: 0;
      padding-left: 1.2em;
      font-size: 14px;
      line-height: 1.7;
    }

    .news-digest-byline { color: var(--muted); font-size: 12px; }

    .news-digest-past {
      display: grid;
      gap: 10px;
      align-content: start;
      padding: clamp(12px, 1.4vw, 16px);
      border: 1px solid rgba(var(--ink-rgb), 0.18);
      border-radius: 12px;
      background: var(--surface);
    }

    .news-digest-past-title {
      display: flex;
      align-items: center;
      gap: 8px;
      margin: 0;
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 820;
      letter-spacing: 0.1em;
    }

    .news-digest-past-title::after { content: ""; flex: 1; height: 1px; background: rgba(var(--ink-rgb), 0.16); }

    .news-digest-past ul { position: relative; list-style: none; margin: 0; padding: 0 0 0 14px; display: grid; gap: 2px; }
    .news-digest-past ul::before { content: ""; position: absolute; left: 4px; top: 12px; bottom: 12px; width: 2px; border-radius: 2px; background: linear-gradient(var(--signal), rgba(11, 99, 206, 0.12)); }

    .news-digest .news-digest-past ul > li { position: relative; margin: 0; padding: 0; border: 0; background: none; box-shadow: none; min-height: 0; }
    .news-digest .news-digest-past ul > li::before { content: ""; position: absolute; left: -14px; top: 13px; width: 10px; height: 10px; border-radius: 50%; background: var(--surface); border: 2px solid var(--signal); box-sizing: border-box; transition: background-color 0.18s ease, transform 0.18s ease; }
    .news-digest .news-digest-past ul > li:hover::before { background: var(--signal); transform: scale(1.15); }

    .news-digest-past li a {
      display: block;
      padding: 7px 8px;
      border-radius: 8px;
      color: var(--ink);
      text-decoration: none;
      transition: background-color 0.18s ease;
    }

    .news-digest-past li a:hover { background: rgba(11, 99, 206, 0.07); }
    .news-digest-past li a:hover .news-digest-past-headline { color: var(--signal); }

    .news-digest-past-copy { display: grid; gap: 3px; min-width: 0; }
    .news-digest-past-meta { display: flex; align-items: center; gap: 6px; color: var(--muted); font-family: var(--font-mono); font-size: 10.5px; font-weight: 720; white-space: nowrap; }
    .news-digest-past-meta b { padding: 1px 7px; border-radius: 999px; background: rgba(11, 99, 206, 0.12); color: var(--signal); font-weight: 820; letter-spacing: 0.04em; }
    .news-digest-past-headline {
      display: -webkit-box;
      overflow: hidden;
      -webkit-box-orient: vertical;
      -webkit-line-clamp: 2;
      font-size: 13px;
      font-weight: 720;
      line-height: 1.5;
    }

    @media (prefers-reduced-motion: reduce) { .news-digest-past li a, .news-digest .news-digest-past ul > li::before { transition: none; } }

    .news-digest-all {
      justify-self: start;
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 820;
      text-decoration: none;
    }

    @media (max-width: 1020px) {
      .news-digest-body { grid-template-columns: 1fr; }
    }

    @media (max-width: 700px) {
      .news-digest { margin-bottom: 28px; }
      .news-digest-latest,
      .news-digest-body:has(> :only-child) .news-digest-latest { grid-template-columns: minmax(0, 1fr) 112px; gap: 12px; padding: 14px 16px; }
      /* 記事一覧までの距離を縮めるため、スマートフォンでは見出しと小さなサムネイルだけの1行にする */
      .news-digest-thumb { grid-column: 2; grid-row: 1; }
      .news-digest-copy { grid-column: 1; grid-row: 1; gap: 6px; }
      .news-digest-headline { font-size: 16px; }
      .news-digest-topics,
      .news-digest-byline,
      .news-digest-lead { display: none; }
    }

    .explore-panel {
      display: grid;
      grid-template-columns: minmax(0, 0.92fr) minmax(280px, 0.58fr);
      gap: clamp(18px, 4vw, 40px);
      align-items: start;
      margin: 0 0 44px;
      padding: clamp(18px, 3vw, 28px) 0;
      border-top: 1px solid rgba(var(--ink-rgb), 0.24);
      border-bottom: 1px solid rgba(var(--ink-rgb), 0.24);
    }

    .explore-search {
      display: grid;
      gap: 14px;
      min-width: 0;
    }

    .explore-search label {
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 820;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    .explore-input-wrap {
      display: grid;
      grid-template-columns: minmax(0, 1fr) auto auto;
      margin: 0;
      min-height: 54px;
      border: 1px solid var(--ink);
      background: var(--surface);
    }

    .explore-input-wrap input {
      width: 100%;
      min-width: 0;
      border: 0;
      padding: 13px 16px;
      background: transparent;
      color: var(--ink);
      font: inherit;
      font-size: 17px;
      line-height: 1.3;
      outline: none;
    }

    .explore-input-wrap button {
      min-width: 52px;
      border: 0;
      border-left: 1px solid var(--ink);
      background: #06131f;
      color: var(--paper);
      font-family: var(--font-mono);
      font-size: 18px;
      font-weight: 820;
      cursor: pointer;
    }

    .explore-input-wrap .explore-submit {
      padding: 0 18px;
      font-family: inherit;
      font-size: 15px;
      letter-spacing: 0.04em;
    }

    .explore-input-wrap .explore-clear {
      min-width: 44px;
      border-left: 0;
      background: transparent;
      color: var(--ink);
      opacity: 0.7;
    }

    .explore-input-wrap .explore-clear[hidden] {
      display: none;
    }

    /* 端末標準の消去ボタンを消し、独自の×（入力中だけ表示）に一本化する */
    .explore-input-wrap input::-webkit-search-cancel-button,
    .explore-input-wrap input::-webkit-search-decoration {
      -webkit-appearance: none;
      appearance: none;
      display: none;
    }

    .explore-input-wrap:focus-within {
      box-shadow: 0 0 0 3px rgba(11, 99, 206, 0.16);
      border-color: var(--signal);
    }

    .explore-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
    }

    .explore-chip {
      min-height: 34px;
      padding: 7px 11px;
      border: 1px solid rgba(var(--ink-rgb), 0.4);
      background: rgba(var(--surface-rgb), 0.72);
      color: var(--ink);
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 820;
      letter-spacing: 0.04em;
      text-transform: uppercase;
      cursor: pointer;
    }

    .explore-more {
      justify-self: start;
      min-height: 32px;
      padding: 6px 2px;
      border: 0;
      background: none;
      color: var(--signal);
      font-size: 13px;
      font-weight: 760;
      cursor: pointer;
    }

    .explore-more::after {
      content: " ▾";
    }

    .explore-more[aria-expanded="true"]::after {
      content: " ▴";
    }

    .explore-more span:not(:empty)::before {
      content: "（";
    }

    .explore-more span:not(:empty)::after {
      content: "）";
    }

    .explore-chip:focus-visible,
    .explore-chip.is-active {
      border-color: var(--signal);
      background: var(--signal);
      color: var(--paper);
      outline: none;
    }

    @media (hover: hover) {
      .explore-chip:hover {
        border-color: var(--signal);
        background: var(--signal);
        color: var(--paper);
      }
    }

    .explore-summary {
      display: grid;
      gap: 12px;
      min-width: 0;
      padding-top: 4px;
    }

    .explore-summary p {
      margin: 0;
      color: var(--muted);
      font-size: 14px;
      line-height: 1.65;
    }

    .explore-count {
      color: var(--ink);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 820;
      letter-spacing: 0.06em;
      text-transform: uppercase;
    }

    .explore-empty {
      display: none;
      margin: 20px 0 0;
      padding: 18px;
      border: 1px solid var(--ink);
      background: var(--surface);
      color: var(--muted);
      font-size: 14px;
    }

    .explore-empty.is-visible {
      display: block;
    }

    .reading-guide {
      display: grid;
      grid-template-columns: minmax(180px, 220px) minmax(0, 1fr);
      gap: 18px;
      align-items: stretch;
      margin: 0 0 28px;
      padding: 16px 0;
      border-top: 1px solid rgba(var(--ink-rgb), 0.22);
      border-bottom: 1px solid rgba(var(--ink-rgb), 0.22);
    }

    .reading-guide h2 {
      margin: 0;
      font-size: clamp(20px, 2vw, 26px);
      font-weight: 820;
      line-height: 1.08;
      letter-spacing: 0.01em;
      display: flex;
      align-items: center;
    }

    .reading-guide-list {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      border-top: 1px solid var(--ink);
      border-left: 1px solid var(--ink);
    }

    .reading-guide-list a {
      display: grid;
      gap: 6px;
      min-height: 88px;
      padding: 12px 14px;
      border-right: 1px solid var(--ink);
      border-bottom: 1px solid var(--ink);
      background: var(--surface);
      text-decoration: none;
      transition: background 0.2s ease, color 0.2s ease;
    }

    .reading-guide-list a:hover,
    .reading-guide-list a:focus-visible {
      background: #06131f;
      color: var(--signal);
      outline: none;
    }

    .reading-guide-list a:hover span,
    .reading-guide-list a:focus-visible span {
      color: var(--paper);
    }

    .reading-guide-list b {
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 780;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    .reading-guide-list span {
      color: var(--ink);
      font-size: 15px;
      font-weight: 760;
      line-height: 1.45;
    }

    .theme-guide {
      margin: 0 0 28px;
      border-top: 1px solid rgba(var(--ink-rgb), 0.22);
      border-bottom: 1px solid rgba(var(--ink-rgb), 0.22);
    }

    .theme-guide-summary {
      display: grid;
      grid-template-columns: auto minmax(0, 1fr) auto;
      gap: 14px 20px;
      align-items: center;
      min-height: 78px;
      padding: 14px 0;
      color: var(--ink);
      cursor: pointer;
      list-style: none;
    }

    .theme-guide-summary::-webkit-details-marker { display: none; }

    .theme-guide-summary:focus-visible {
      outline: 2px solid var(--signal);
      outline-offset: 4px;
    }

    .theme-guide-heading {
      display: grid;
      gap: 3px;
    }

    .theme-guide-title {
      font-size: clamp(20px, 2vw, 26px);
      font-weight: 820;
      line-height: 1.15;
      letter-spacing: 0.01em;
    }

    .theme-guide-summary-note {
      color: var(--muted);
      font-size: 13px;
      line-height: 1.45;
    }

    .theme-guide-summary-action {
      display: inline-flex;
      align-items: center;
      justify-content: flex-end;
      gap: 10px;
      min-height: 44px;
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 820;
      letter-spacing: 0.06em;
      text-transform: uppercase;
    }

    .theme-guide-summary-action::before { content: "7テーマを見る"; }
    .theme-guide[open] .theme-guide-summary-action::before { content: "閉じる"; }

    .theme-guide-summary-arrow {
      display: grid;
      place-items: center;
      width: 34px;
      height: 34px;
      border: 1px solid currentColor;
      transition: transform 0.2s ease;
    }

    .theme-guide[open] .theme-guide-summary-arrow { transform: rotate(180deg); }

    .theme-guide-content {
      padding: 0 0 18px;
    }

    .theme-index {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
      gap: 0;
      margin: 0;
      padding: 0;
      list-style: none;
      border-top: 1px solid var(--ink);
      border-left: 1px solid var(--ink);
    }

    .theme-card {
      display: grid;
      gap: 10px;
      padding: 16px;
      border-right: 1px solid var(--ink);
      border-bottom: 1px solid var(--ink);
      background: var(--surface);
    }

    .theme-card-head {
      display: flex;
      align-items: baseline;
      justify-content: space-between;
      gap: 12px;
      text-decoration: none;
      color: var(--ink);
    }

    .theme-card-head:hover .theme-card-title,
    .theme-card-head:focus-visible .theme-card-title {
      text-decoration: underline;
      text-underline-offset: 3px;
    }

    .theme-card-title {
      font-size: 17px;
      font-weight: 800;
      line-height: 1.35;
    }

    .theme-card-count {
      flex: none;
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 780;
      letter-spacing: 0.06em;
      color: rgba(var(--ink-rgb), 0.7);
    }

    .theme-card-desc {
      margin: 0;
      font-size: 13px;
      line-height: 1.6;
      color: rgba(var(--ink-rgb), 0.78);
    }

    .theme-card-picks {
      margin: 0;
      padding: 0;
      list-style: none;
      display: grid;
      gap: 6px;
    }

    .theme-card-picks a {
      font-size: 13.5px;
      line-height: 1.5;
      color: var(--ink);
      text-decoration: none;
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }

    .theme-card-picks a::before {
      content: "→ ";
      color: rgba(var(--ink-rgb), 0.55);
    }

    .theme-card-picks a:hover,
    .theme-card-picks a:focus-visible {
      text-decoration: underline;
      text-underline-offset: 3px;
    }

    .news-sections {
      display: grid;
      gap: clamp(34px, 5vw, 58px);
    }

    .news-category {
      display: grid;
      gap: 18px;
    }

    .news-category-head {
      display: flex;
      flex-wrap: wrap;
      align-items: baseline;
      gap: 12px 22px;
      padding-bottom: 14px;
      border-bottom: 1px solid rgba(var(--ink-rgb), 0.22);
    }

    .news-category-label {
      color: var(--signal);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 780;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    .news-category-head :is(h2, h3) {
      margin: 0;
      font-size: clamp(20px, 2vw, 26px);
      font-weight: 820;
      line-height: 1.08;
      letter-spacing: 0.01em;
    }

    .news-list {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(min(270px, 100%), 1fr));
      border-top: 1px solid var(--ink);
      border-left: 1px solid var(--ink);
    }

    .news-item {
      display: grid;
      min-height: 260px;
      padding: 18px;
      border-right: 1px solid var(--ink);
      border-bottom: 1px solid var(--ink);
      background: var(--card-gradient);
    }

    .news-item[hidden] { display: none; }

    .news-item.is-filtered-out,
    .catalog-card.is-collapsed,
    .catalog-card.is-filtered-out {
      display: none;
    }

    .news-thumb {
      display: block;
      margin-bottom: 14px;
      overflow: hidden;
      border: 1px solid rgba(var(--ink-rgb), 0.18);
      background: rgba(var(--ink-rgb), 0.05);
    }

    .news-thumb img {
      display: block;
      width: 100%;
      aspect-ratio: 16 / 9;
      height: auto;
      object-fit: cover;
      transition: transform 0.32s ease;
    }

    .news-item:hover .news-thumb img,
    .news-item:focus-within .news-thumb img {
      transform: scale(1.035);
    }

    .news-item time,
    .news-source {
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 780;
      letter-spacing: 0.06em;
      text-transform: uppercase;
    }

    .news-item time { color: var(--signal); }

    .news-meta {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 8px;
    }

    .news-tag {
      display: inline-flex;
      align-items: center;
      padding: 0 6px;
      border: 1px solid var(--ink);
      color: var(--ink);
      font-family: var(--font-mono);
      font-size: 9px;
      font-weight: 780;
      letter-spacing: 0.06em;
      text-transform: uppercase;
    }

    .news-topic-tags,
    .archive-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 5px;
    }

    .news-topic-tags {
      margin-top: 9px;
    }

    .news-topic-tags span,
    .archive-tags span {
      display: inline-flex;
      align-items: center;
      min-height: 22px;
      padding: 2px 7px;
      border: 1px solid rgba(var(--ink-rgb), 0.34);
      background: rgba(var(--surface-rgb), 0.72);
      color: var(--ink);
      font-family: var(--font-mono);
      font-size: 9px;
      font-weight: 820;
      letter-spacing: 0.06em;
      line-height: 1.1;
      text-transform: uppercase;
    }

    .news-item h3 {
      margin: 12px 0 10px;
      font-size: 17px;
      font-weight: 820;
      line-height: 1.34;
      letter-spacing: 0.01em;
    }

    .news-item h3 a { overflow-wrap: anywhere; }

    .news-item h3 a:hover,
    .news-item h3 a:focus-visible {
      color: var(--signal);
      outline: none;
    }

    .news-summary {
      margin: 0 0 12px;
      color: var(--muted);
      font-size: 13.5px;
      line-height: 1.6;
      font-weight: 450;
    }

    .news-source {
      align-self: end;
      color: var(--ink);
    }

    .news-actions[hidden] { display: none; }

    .research-cta {
      display: grid;
      grid-template-columns: minmax(0, 1fr) minmax(280px, 360px);
      gap: clamp(24px, 5vw, 54px);
      align-items: center;
      max-width: 980px;
      margin: 48px auto 0;
      padding: clamp(28px, 5vw, 48px);
      border: 1px solid var(--ink);
      border-top: 4px solid var(--signal);
      background: var(--ink);
      color: var(--paper);
    }

    .research-cta-copy {
      display: grid;
      gap: 10px;
    }

    .research-cta-kicker {
      margin: 0;
      color: #7cbcff;
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 820;
      letter-spacing: 0.12em;
      text-transform: uppercase;
    }

    .research-cta h2 {
      margin: 0;
      color: var(--paper);
      font-size: clamp(24px, 3vw, 34px);
      line-height: 1.25;
    }

    .research-cta-description {
      margin: 0;
      color: rgba(248, 247, 242, 0.76);
      font-size: 14px;
      line-height: 1.7;
    }

    .research-cta-actions {
      display: grid;
      gap: 14px;
    }

    .research-cta-primary {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      min-height: 52px;
      padding: 12px 16px;
      border: 1px solid var(--signal);
      background: var(--signal);
      color: var(--paper);
      font-size: 14px;
      font-weight: 820;
      line-height: 1.45;
      text-decoration: none;
      transition: background 0.2s ease, border-color 0.2s ease;
    }

    .research-cta-primary:hover,
    .research-cta-primary:focus-visible {
      border-color: #7cbcff;
      background: #084f9f;
      outline: 2px solid #7cbcff;
      outline-offset: 3px;
    }

    .research-cta-secondary {
      margin: 0;
      color: rgba(248, 247, 242, 0.72);
      font-size: 13px;
      line-height: 1.65;
    }

    .research-cta-secondary a {
      color: var(--paper);
      font-weight: 760;
      text-decoration: underline;
      text-underline-offset: 3px;
    }

    .research-cta-secondary a:hover,
    .research-cta-secondary a:focus-visible {
      color: #7cbcff;
      outline: none;
    }

    .site-footer {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      gap: 10px 16px;
      padding: 18px clamp(20px, 4vw, 58px);
      background: var(--footer-gradient);
      box-shadow: inset 0 1px 0 rgba(var(--ink-rgb), 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;
    }

    .article-catalog {
      margin-top: clamp(34px, 5vw, 58px);
      display: grid;
      gap: 18px;
    }

    .archive-list {
      list-style: none;
      margin: 0;
      padding: 0;
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      border-top: 1px solid var(--ink);
      border-left: 1px solid var(--ink);
    }

    .archive-list li {
      display: flex;
      flex-direction: column;
      min-height: 300px;
      border-right: 1px solid var(--ink);
      border-bottom: 1px solid var(--ink);
      background: var(--card-gradient);
    }

    .archive-thumb {
      display: block;
      overflow: hidden;
      border-bottom: 1px solid rgba(var(--ink-rgb), 0.2);
      background: rgba(var(--ink-rgb), 0.05);
    }

    .archive-thumb img {
      display: block;
      width: 100%;
      aspect-ratio: 16 / 9;
      height: auto;
      object-fit: cover;
      transition: transform 0.32s ease;
    }

    .catalog-card:hover .archive-thumb img,
    .catalog-card:focus-within .archive-thumb img {
      transform: scale(1.035);
    }

    .archive-card-body {
      display: grid;
      align-content: start;
      gap: 9px;
      padding: 14px;
      flex: 1;
    }

    .archive-meta {
      display: flex;
      flex-wrap: wrap;
      gap: 4px 10px;
      align-items: center;
    }

    .archive-list time,
    .archive-kind {
      color: var(--muted);
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 780;
      letter-spacing: 0.06em;
      text-transform: uppercase;
    }

    .archive-list time { color: var(--signal); }

    .archive-kind {
      display: inline-flex;
      align-items: center;
      padding: 0 6px;
      border: 1px solid var(--ink);
      color: var(--ink);
      font-size: 9px;
    }

    .archive-title {
      font-size: 15px;
      font-weight: 820;
      line-height: 1.42;
      overflow-wrap: anywhere;
    }

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

    .archive-source {
      color: var(--muted);
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 780;
      letter-spacing: 0.05em;
      text-transform: uppercase;
    }

    .catalog-actions {
      display: flex;
      justify-content: center;
      padding-top: 20px;
    }

    .catalog-more {
      position: relative;
      display: inline-grid;
      grid-template-columns: auto auto;
      grid-template-areas:
        "kicker arrow"
        "main arrow";
      align-items: center;
      gap: 2px 18px;
      min-width: min(100%, 360px);
      min-height: 74px;
      padding: 14px 18px;
      border: 1px solid var(--ink);
      background:
        linear-gradient(90deg, var(--signal) 0 4px, transparent 4px),
        var(--card-gradient);
      color: var(--ink);
      text-align: left;
      cursor: pointer;
      transition:
        border-color 0.22s ease,
        background-color 0.22s ease,
        color 0.22s ease,
        transform 0.22s ease;
    }

    .catalog-more::after {
      content: "";
      position: absolute;
      inset: 6px;
      border: 1px solid rgba(var(--ink-rgb), 0.12);
      pointer-events: none;
    }

    .catalog-more:hover,
    .catalog-more:focus-visible {
      border-color: var(--signal);
      background:
        linear-gradient(90deg, var(--signal) 0 4px, transparent 4px),
        var(--card-hover-gradient);
      color: var(--signal);
      outline: none;
      transform: translateY(-2px);
    }

    .catalog-more-kicker,
    .catalog-more-count {
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 820;
      letter-spacing: 0.08em;
      line-height: 1;
      text-transform: uppercase;
    }

    .catalog-more-kicker {
      grid-area: kicker;
      color: var(--signal);
    }

    .catalog-more-main {
      grid-area: main;
      display: flex;
      flex-wrap: wrap;
      align-items: baseline;
      gap: 8px;
      font-size: 16px;
      font-weight: 850;
      letter-spacing: 0.01em;
      line-height: 1.25;
    }

    .catalog-more-count {
      color: var(--muted);
    }

    .catalog-more-arrow {
      grid-area: arrow;
      display: grid;
      place-items: center;
      width: 38px;
      height: 38px;
      margin-left: auto;
      border: 1px solid currentColor;
      font-family: var(--font-mono);
      font-size: 18px;
      line-height: 1;
      transition: transform 0.22s ease;
    }

    .catalog-more:hover .catalog-more-arrow,
    .catalog-more:focus-visible .catalog-more-arrow {
      transform: translateY(2px);
    }

    .catalog-more[hidden] {
      display: none;
    }

    html[data-color-mode="dark"] body {
      background: var(--page);
      color: var(--ink);
    }

    html[data-color-mode="dark"] .site-header {
      background: #091722;
      box-shadow: inset 0 -1px 0 rgba(var(--ink-rgb), 0.16);
    }

    html[data-color-mode="dark"] .site-header .brand-lockup,
    html[data-color-mode="dark"] .site-header .brand-symbol,
    html[data-color-mode="dark"] .site-header .brand-wordmark {
      filter: brightness(0) invert(1);
    }

    html[data-color-mode="dark"] .site-header .nav-menu {
      border-color: rgba(var(--ink-rgb), 0.42);
      background: var(--surface);
      box-shadow: 0 18px 34px rgba(0, 0, 0, 0.42);
    }

    html[data-color-mode="dark"] .site-header .nav-group:hover .nav-trigger,
    html[data-color-mode="dark"] .site-header .nav-group:focus-within .nav-trigger,
    html[data-color-mode="dark"] .site-header .nav-group.is-open .nav-trigger,
    html[data-color-mode="dark"] .site-header .nav-direct:hover,
    html[data-color-mode="dark"] .site-header .nav-direct:focus-visible {
      border-color: rgba(124, 188, 255, 0.52);
    }

    html[data-color-mode="dark"] .site-header .translate-slot select {
      border-color: rgba(var(--ink-rgb), 0.3);
      background-color: rgba(var(--surface-rgb), 0.92);
      background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='6' height='4' viewBox='0 0 6 4'%3E%3Cpath d='M0 0h6L3 4z' fill='%23edf4fa'/%3E%3C/svg%3E");
    }

    html[data-color-mode="dark"] .site-header .translate-slot select:hover,
    html[data-color-mode="dark"] .site-header .translate-slot select:focus-visible,
    html[data-color-mode="dark"] .site-header .translate-slot option {
      background-color: var(--surface);
    }

    html[data-color-mode="dark"] .translation-archive-link,
    html[data-color-mode="dark"] .explore-input-wrap .explore-submit {
      border-color: #0b63ce;
      background: #0b63ce;
      color: #ffffff;
    }

    @media (max-width: 700px) {
      html[data-color-mode="dark"] .translation-archive-link {
        background: none;
        color: var(--signal);
      }
    }

    html[data-color-mode="dark"] .explore-input-wrap,
    html[data-color-mode="dark"] .explore-empty,
    html[data-color-mode="dark"] .reading-guide-list a,
    html[data-color-mode="dark"] .theme-card {
      background: var(--surface);
    }

    html[data-color-mode="dark"] .reading-guide-list a:hover,
    html[data-color-mode="dark"] .reading-guide-list a:focus-visible {
      background: #143149;
    }

    html[data-color-mode="dark"] .news-item,
    html[data-color-mode="dark"] .archive-list li {
      background: var(--card-gradient);
    }

    html[data-color-mode="dark"] .research-cta {
      border-color: #2b4154;
      border-top-color: #7cbcff;
      background:
        radial-gradient(circle at 90% 20%, rgba(11, 99, 206, 0.42), transparent 38%),
        #06131f;
      color: #ffffff;
    }

    html[data-color-mode="dark"] .research-cta h2,
    html[data-color-mode="dark"] .research-cta-primary,
    html[data-color-mode="dark"] .research-cta-secondary a {
      color: #ffffff;
    }

    html[data-color-mode="dark"] .site-footer {
      background: var(--footer-gradient);
    }

    @media (max-width: 1020px) {
      .archive-list {
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }
    }

    @media (max-width: 760px) {
      .site-header {
        align-items: flex-start;
        padding: 16px 20px 12px;
      }

      .brand-symbol { width: 36px; }
      .brand-wordmark { width: 96px; }

      .back-link {
        margin-left: auto;
        padding-top: 9px;
        font-size: 10px;
      }

      main {
        padding: 42px 20px 72px;
      }

      h1 {
        font-size: clamp(32px, 10vw, 42px);
      }

      .explore-panel {
        grid-template-columns: 1fr;
        gap: 18px;
        margin-bottom: 34px;
      }

      .explore-input-wrap {
        grid-template-columns: minmax(0, 1fr) auto auto;
      }

      .explore-input-wrap .explore-submit {
        padding: 0 14px;
      }

      .explore-input-wrap input {
        font-size: 16px;
      }

      .explore-tags {
        gap: 6px;
      }

      .explore-tags.is-collapsed {
        max-height: 70px;
        overflow: hidden;
      }

      .explore-chip {
        min-height: 32px;
        padding: 6px 10px;
      }

      .explore-summary p {
        display: none;
      }

      .reading-guide,
      .theme-guide {
        margin-bottom: 24px;
      }

      .reading-guide {
        grid-template-columns: 1fr;
        gap: 12px;
        padding: 16px 0;
      }

      .reading-guide-list,
      .news-list {
        grid-template-columns: 1fr;
      }

      .reading-guide-list a {
        grid-template-columns: auto minmax(0, 1fr);
        align-items: center;
        gap: 12px;
        min-height: 0;
        padding: 12px 14px;
      }

      .reading-guide-list span { font-size: 13px; }

      .theme-guide-summary {
        grid-template-columns: auto minmax(0, 1fr);
        gap: 10px 14px;
      }

      .theme-guide-summary-action {
        grid-column: 1 / -1;
        justify-content: space-between;
        width: 100%;
        padding-top: 8px;
        border-top: 1px solid rgba(var(--ink-rgb), 0.14);
      }

      .research-cta {
        grid-template-columns: 1fr;
        gap: 24px;
      }

      .news-category-head {
        align-items: flex-start;
      }

      .archive-list {
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }

      .archive-list li { min-height: 0; }

      .archive-card-body {
        gap: 7px;
        padding: 10px;
      }

      .archive-title {
        font-size: 13px;
        line-height: 1.4;
        display: -webkit-box;
        -webkit-box-orient: vertical;
        -webkit-line-clamp: 3;
        overflow: hidden;
      }

      .archive-tags { display: none; }

      .archive-list time,
      .archive-kind { font-size: 9px; }
    }

    /* 右の特集列。記事一覧を冒頭に出すため、ニュースまとめ・AI 2040・翻訳・動画・はじめて読むならを
       /videos のミーム列と同じ細い列へ寄せる（900px以上）。狭い画面では記事4本の後に挟む。
       文字を減らし、画像（最新号・動画のサムネイル、入口のイラスト）で見分けられるカードにする。 */
    .research-side { display: grid; gap: 12px; align-content: start; margin-top: 34px; }
    .research-side-title {
      margin: 0 0 2px;
      padding-bottom: 6px;
      border-bottom: 3px solid var(--signal);
      color: var(--ink);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 820;
      letter-spacing: 0.12em;
    }
    .research-side .book-door {
      display: grid; grid-template-columns: 56px minmax(0, 1fr); align-items: center; gap: 12px; padding: 12px;
      border-radius: 12px; border: 1px solid #0b2338; background: #06131f; color: #f8f7f2; text-decoration: none;
      transition: border-color 0.18s ease, transform 0.18s ease;
    }
    .research-side .book-door:hover, .research-side .book-door:focus-visible { border-color: var(--signal); transform: translateY(-1px); outline: none; }
    .research-side .book-door-cover img { display: block; width: 56px; height: auto; border: 1px solid rgba(248, 247, 242, 0.3); }
    .research-side .book-door-copy { display: grid; gap: 3px; }
    .research-side .book-door-kicker { color: #8fc0ff; font-size: 11px; font-weight: 780; letter-spacing: 0.06em; }
    .research-side .book-door h2 { margin: 0; color: #f8f7f2; font-size: 15px; line-height: 1.35; }
    .research-side .book-door .side-sub { color: rgba(248, 247, 242, 0.76); }
    .research-side .side-illust { display: block; flex: none; width: 64px; height: 64px; overflow: hidden; border-radius: 10px; background: #f8f7f2; }
    .research-side .side-illust img { display: block; width: 100%; height: 100%; object-fit: cover; }
    .research-side .side-sub { display: block; color: var(--muted); font-size: 12px; line-height: 1.5; font-weight: 600; }
    /* 横長カード: イラスト＋見出し1行＋補足1行 */
    .research-side .ai2040-project,
    .research-side .translation-archive {
      display: grid;
      grid-template-columns: 64px minmax(0, 1fr);
      align-items: center;
      gap: 12px;
      padding: 12px;
      border-radius: 12px;
      border: 1px solid rgba(var(--ink-rgb), 0.18);
      background: var(--surface);
      transition: border-color 0.18s ease, transform 0.18s ease;
    }
    .research-side .ai2040-project:hover,
    .research-side .translation-archive:hover,
    .research-side .video-door:hover,
    .research-side .news-digest-latest:hover,
    .research-side .reading-guide-list a:hover { border-color: var(--signal); transform: translateY(-1px); }
    .research-side .ai2040-project { border-color: #0b2338; color: #f8f7f2; background: radial-gradient(circle at 92% 20%, rgba(11, 99, 206, 0.7), transparent 45%), linear-gradient(135deg, #02080d 0%, #071928 70%, #0b63ce 160%); }
    .research-side .ai2040-project h2 { color: #f8f7f2; }
    .research-side .ai2040-project .side-sub { color: rgba(248, 247, 242, 0.76); }
    .research-side .ai2040-project .side-illust { background: #f8f7f2; }
    .research-side .ai2040-project::after,
    .research-side .ai2040-project-kicker,
    .research-side .translation-archive-kicker,
    .research-side .ai2040-project-copy > p:not([class]),
    .research-side .translation-archive-copy > p:not([class]),
    .research-side .ai2040-project-cta { display: none; }
    .research-side .translation-archive-link { grid-column: 2; display: flex; gap: 4px; min-height: 0; margin-top: -8px; padding: 0; border: 0; background: none; color: var(--signal); font-size: 12px; font-weight: 700; white-space: normal; }
    .research-side .ai2040-project-copy,
    .research-side .translation-archive-copy { display: grid; gap: 3px; }
    .research-side .ai2040-project h2,
    .research-side .translation-archive h2 { margin: 0; font-size: 15px; line-height: 1.35; }
    .research-side .ai2040-project-note { margin: 6px 0 0 4px; font-size: 12px; }
    .research-side .research-doors { grid-template-columns: 1fr; gap: 12px; margin: 0; }
    /* 動画: サムネイルを主役にし、見出しはサムネイルの下に1行 */
    .research-side .video-door { gap: 8px; padding: 0; border: 1px solid rgba(var(--ink-rgb), 0.18); border-radius: 12px; overflow: hidden; background: var(--surface); }
    .research-side .video-door { grid-template-columns: 1fr; align-items: stretch; }
    .research-side .video-door-thumb { grid-column: auto; grid-row: auto; }
    .research-side .video-door-kicker { display: none; }
    .research-side .video-door-thumb { display: block; }
    .research-side .video-door-foot { padding: 0 12px 10px; align-items: center; }
    .research-side .video-door h2 { font-size: 15px; margin: 0; }
    .research-side .video-door-link { font-size: 12px; }
    /* AIニュースまとめ: 最新号のサムネイルに「最新号」を重ね、見出しだけを添える */
    .research-side .news-digest { gap: 6px; margin: 0; }
    .research-side .news-digest .news-category-head { display: flex; align-items: baseline; gap: 8px; margin: 0; }
    .research-side .news-digest .news-category-label { display: none; }
    .research-side .news-digest h2 { font-size: 15px; margin: 0; }
    .research-side .news-digest .news-category-head::after { content: "毎週更新"; color: var(--muted); font-size: 11px; font-weight: 700; }
    .research-side .news-digest-lead,
    .research-side .news-digest-topics,
    .research-side .news-digest-byline { display: none; }
    .research-side .news-digest-body,
    .research-side .news-digest-body:has(> :only-child) { grid-template-columns: 1fr; }
    .research-side .news-digest-latest,
    .research-side .news-digest-body:has(> :only-child) .news-digest-latest {
      position: relative;
      display: grid;
      grid-template-columns: 1fr;
      gap: 0;
      padding: 0;
      border: 1px solid rgba(var(--ink-rgb), 0.18);
      border-radius: 12px;
      overflow: hidden;
      transition: border-color 0.18s ease, transform 0.18s ease;
    }
    .research-side .news-digest-thumb,
    .research-side .news-digest-copy { grid-column: auto; grid-row: auto; }
    .research-side .news-digest-copy { gap: 4px; padding: 10px 12px 12px; }
    .research-side .news-digest-meta { font-size: 11px; }
    .research-side .news-digest-badge { position: absolute; top: 8px; left: 8px; border-radius: 4px; }
    .research-side .news-digest-headline { font-size: 14px; line-height: 1.5; }
    /* はじめて読むなら: イラストと短い名前の3枚 */
    .research-side .reading-guide { display: grid; grid-template-columns: 1fr; gap: 8px; margin: 4px 0 0; padding: 0; border: 0; }
    .research-side .reading-guide h2 { font-size: 15px; }
    .research-side .reading-guide-list { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; border: 0; }
    .research-side .reading-guide-list a {
      display: grid;
      justify-items: center;
      gap: 2px;
      min-height: 0;
      padding: 8px 4px 10px;
      border: 1px solid rgba(var(--ink-rgb), 0.18);
      border-radius: 12px;
      grid-template-columns: 1fr;
      text-align: center;
      transition: border-color 0.18s ease, transform 0.18s ease;
    }
    .research-side .reading-guide-list a:hover { background: var(--surface); }
    .research-side .reading-guide-list a:hover span,
    .research-side .reading-guide-list a:hover .side-guide-label { color: var(--signal); }
    .research-side .reading-guide-list .side-illust { width: 100%; height: auto; aspect-ratio: 1; max-width: 72px; margin-bottom: 4px; }
    .research-side .side-guide-label { color: var(--ink); font-size: 13px; font-weight: 800; line-height: 1.3; }
    .research-side .side-guide-sub { color: var(--muted); font-size: 10px; line-height: 1.4; }
    .research-side .side-guide-label, .research-side .side-guide-sub { display: block; }
    html[data-color-mode="dark"] .research-side .reading-guide-list a,
    html[data-color-mode="dark"] .research-side .translation-archive,
    html[data-color-mode="dark"] .research-side .video-door { border-color: #2b4154; }
    html[data-color-mode="dark"] .research-side .side-guide-label { color: #ffffff; }
    html[data-color-mode="dark"] .research-side .translation-archive-link { border: 0; background: none; color: #7cbcff; }
    .research-side,
    .research-side > *,
    .research-side .research-doors > *,
    .qa-closeup { display: grid; gap: 10px; padding: 14px; border: 1px solid var(--line); background: var(--paper); }
    .qa-closeup-head { display: grid; gap: 2px; }
    .qa-closeup-label { color: var(--signal); font-family: var(--font-mono); font-size: 11px; font-weight: 800; letter-spacing: 0.1em; }
    .qa-closeup-head h2 { margin: 0; font-size: 15px; line-height: 1.4; }
    .qa-closeup-list { display: grid; gap: 12px; margin: 0; padding: 0; list-style: none; }
    .qa-closeup-card { display: grid; gap: 6px; color: inherit; text-decoration: none; }
    .qa-closeup-thumb { display: block; aspect-ratio: 16 / 9; overflow: hidden; border: 1px solid var(--line); }
    .qa-closeup-thumb img { display: block; width: 100%; height: 100%; object-fit: cover; transition: transform .4s ease; }
    .qa-closeup-card:hover .qa-closeup-thumb img, .qa-closeup-card:focus-visible .qa-closeup-thumb img { transform: scale(1.04); }
    .qa-closeup-card:hover .qa-closeup-title, .qa-closeup-card:focus-visible .qa-closeup-title { color: var(--signal); }
    .qa-closeup-card:focus-visible { outline: 2px solid var(--signal); outline-offset: 3px; }
    .qa-closeup-copy { display: grid; gap: 2px; }
    .qa-closeup-title { font-size: 14px; font-weight: 820; line-height: 1.45; }
    .qa-closeup-sub { font-size: 12px; font-weight: 700; color: var(--muted); }
    .catalog-feature .qa-closeup { grid-column: 1 / -1; }
    @media (min-width: 560px) and (max-width: 899px) { .catalog-feature .qa-closeup-list { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
    @media (prefers-reduced-motion: reduce) { .qa-closeup-thumb img { transition: none; } .qa-closeup-card:hover .qa-closeup-thumb img { transform: none; } }
    /* 特集列の装飾（本人依頼「右列の装飾はもっと工夫してほしい」）。
       箱の中に箱が並ぶ見え方をやめ、雑誌の目次のように番号付きの罫で区切る。
       入口はトップのリサーチ欄と同じモノクロ写真調（青を一点）の画像を主役にし、文字は見出し1行＋補足1行のまま。 */
    aside.research-side { counter-reset: side-sec; gap: 22px; padding: 0; border: 0; background: none; }
    aside.research-side > *,
    aside.research-side .research-doors > * { padding: 0; border: 0; background: none; }
    aside.research-side .research-side-title {
      display: flex; align-items: baseline; justify-content: space-between; gap: 8px;
      margin: 0; padding: 10px 0 9px;
      border-top: 4px solid var(--ink); border-bottom: 1px solid var(--ink);
      font-family: var(--font-sans); font-size: 20px; font-weight: 860; letter-spacing: 0.08em; line-height: 1.2;
    }
    aside.research-side .research-side-title::after {
      content: "FEATURES"; color: var(--signal);
      font-family: var(--font-mono); font-size: 11px; font-weight: 800; letter-spacing: 0.2em;
    }
    /* 節の見出し: 番号＋名前＋右へ伸びる細い罫 */
    aside.research-side .side-sec-label,
    aside.research-side .qa-closeup-label,
    aside.research-side .reading-guide h2 {
      counter-increment: side-sec;
      display: flex; align-items: center; gap: 8px;
      margin: 0; color: var(--ink);
      font-family: var(--font-sans); font-size: 13px; font-weight: 820; letter-spacing: 0.06em; line-height: 1.3;
    }
    aside.research-side .side-sec-label::before,
    aside.research-side .qa-closeup-label::before,
    aside.research-side .reading-guide h2::before,
    aside.research-side .news-digest .news-category-head::before {
      content: counter(side-sec, decimal-leading-zero);
      color: var(--signal); font-family: var(--font-mono); font-size: 11px; font-weight: 800; letter-spacing: 0.04em;
    }
    aside.research-side .side-sec-label::after,
    aside.research-side .qa-closeup-label::after,
    aside.research-side .reading-guide h2::after {
      content: ""; flex: 1; height: 1px; background: var(--line);
    }
    /* 『知能爆発』: 表紙を少し立てて光を当てる */
    aside.research-side .book-door {
      position: relative; overflow: hidden;
      grid-template-columns: 66px minmax(0, 1fr); gap: 14px; padding: 16px 14px 16px 16px;
      border: 1px solid #0b2338; border-radius: 12px;
      background:
        radial-gradient(circle at 22% 55%, rgba(11, 99, 206, 0.62) 0%, rgba(11, 99, 206, 0) 46%),
        linear-gradient(135deg, #02080d 0%, #071928 72%, #0b2a48 100%);
    }
    aside.research-side .book-door-cover { display: block; perspective: 420px; }
    aside.research-side .book-door-cover img {
      width: 66px; border: 0;
      transform: rotateY(20deg) rotateZ(-2deg); transform-origin: left center;
      box-shadow: 8px 12px 18px rgba(0, 0, 0, 0.55), inset -2px 0 0 rgba(255, 255, 255, 0.2);
      transition: transform 0.35s ease;
    }
    aside.research-side .book-door:hover .book-door-cover img,
    aside.research-side .book-door:focus-visible .book-door-cover img { transform: rotateY(0deg) rotateZ(0deg) scale(1.04); }
    aside.research-side .book-door-kicker {
      justify-self: start; padding: 1px 8px; border-radius: 999px;
      background: #0b63ce; color: #ffffff; font-size: 11px; letter-spacing: 0.08em;
    }
    aside.research-side .book-door h2 { font-size: 16px; }
    /* クローズアップ */
    aside.research-side .qa-closeup { gap: 10px; }
    aside.research-side .qa-closeup-head { gap: 6px; }
    aside.research-side .qa-closeup-head h2 { font-size: 15px; }
    aside.research-side .qa-closeup-thumb { border-radius: 10px; border-color: rgba(var(--ink-rgb), 0.16); }
    /* AIニュースまとめ: 見出しを他の節と同じ番号付きにし、「毎週更新」に青い点を添える */
    aside.research-side .news-digest { counter-increment: side-sec; gap: 10px; }
    aside.research-side .news-digest .news-category-head { align-items: center; gap: 8px; }
    aside.research-side .news-digest h2 { font-size: 13px; font-weight: 820; letter-spacing: 0.06em; }
    aside.research-side .news-digest .news-category-head::after {
      content: "毎週更新"; flex: 1; text-align: right;
      padding-left: 14px; border-left: 0;
      background: linear-gradient(var(--line), var(--line)) left 50% / calc(100% - 64px) 1px no-repeat;
      color: var(--muted); font-size: 11px; font-weight: 700;
    }
    aside.research-side .news-digest h2::after {
      content: ""; display: inline-block; width: 7px; height: 7px; margin-left: 8px; vertical-align: 2px;
      border-radius: 50%; background: #0b63ce;
    }
    aside.research-side .news-digest-latest { border-radius: 12px; }
    /* 特設・翻訳 */
    aside.research-side .research-doors { gap: 12px; }
    /* AI 2040・AI 2027: 写真を全面に敷き、下の暗がりに題を載せる */
    aside.research-side .research-doors .ai2040-project {
      position: relative; isolation: isolate; display: block; overflow: hidden;
      aspect-ratio: 2 / 1; padding: 0;
      border: 1px solid #0b2338; border-radius: 12px; background: #02080d;
    }
    aside.research-side .research-doors .ai2040-project .side-illust {
      position: absolute; inset: 0; z-index: -2; width: 100%; height: 100%; border-radius: 0; background: #02080d;
    }
    aside.research-side .research-doors .ai2040-project .side-illust img { transition: transform 0.6s ease; }
    aside.research-side .research-doors .ai2040-project:hover .side-illust img,
    aside.research-side .research-doors .ai2040-project:focus-visible .side-illust img { transform: scale(1.06); }
    aside.research-side .research-doors .ai2040-project::before {
      content: ""; position: absolute; inset: 0; z-index: -1;
      background: linear-gradient(180deg, rgba(2, 8, 13, 0) 28%, rgba(2, 8, 13, 0.9) 100%);
    }
    aside.research-side .research-doors .ai2040-project-copy {
      position: absolute; left: 14px; right: 14px; bottom: 11px; gap: 1px;
    }
    aside.research-side .research-doors .ai2040-project h2 { font-size: 16px; text-shadow: 0 1px 8px rgba(0, 0, 0, 0.6); }
    aside.research-side .research-doors .ai2040-project .side-sub { color: rgba(248, 247, 242, 0.82); }
    aside.research-side .research-doors .ai2040-project-note { margin: 6px 0 0 2px; }
    /* Phase Lock・翻訳資料・寄稿: 写真の小窓＋題の目次行 */
    aside.research-side .research-doors .translation-archive {
      grid-template-columns: 58px minmax(0, 1fr); gap: 12px; padding: 12px 0 0;
      border: 0; border-top: 1px solid var(--line); border-radius: 0; background: none;
    }
    aside.research-side .research-doors .translation-archive:hover { transform: none; }
    aside.research-side .research-doors .translation-archive:hover h2 { color: var(--signal); }
    aside.research-side .research-doors .translation-archive .side-illust {
      width: 58px; height: 58px; border-radius: 8px; background: #02080d;
      box-shadow: inset 0 0 0 1px rgba(var(--ink-rgb), 0.12);
    }
    aside.research-side .research-doors .translation-archive .side-illust img { transition: transform 0.5s ease; }
    aside.research-side .research-doors .translation-archive:hover .side-illust img { transform: scale(1.1); }
    aside.research-side .research-doors .translation-archive-link { margin-top: -6px; }
    /* 動画: 既存の再生マークを丸くして、サムネイルの文字を隠しにくくする */
    aside.research-side .research-doors .video-door { border: 1px solid rgba(var(--ink-rgb), 0.18); border-radius: 12px; background: var(--surface); }
    aside.research-side .video-door-thumb::after {
      left: 12px; top: auto; bottom: 10px; width: 38px; height: 38px; padding-left: 2px;
      border-radius: 50%; font-size: 13px; transform: none;
      box-shadow: 0 0 0 1.5px rgba(248, 247, 242, 0.85);
    }
    /* はじめて読むなら: 1→2→3 の順に読む道筋を線と番号で見せる */
    aside.research-side .reading-guide { gap: 12px; margin: 0; }
    aside.research-side .reading-guide-list { position: relative; counter-reset: side-step; gap: 10px; }
    aside.research-side .reading-guide-list::before {
      content: ""; position: absolute; left: 16%; right: 16%; top: 36px; height: 0;
      border-top: 1px dashed rgba(var(--ink-rgb), 0.4);
    }
    aside.research-side .reading-guide-list a {
      position: relative; counter-increment: side-step; padding: 0 0 4px; border: 0; background: none; gap: 3px;
    }
    aside.research-side .reading-guide-list a:hover { background: none; }
    aside.research-side .reading-guide-list a::before {
      content: counter(side-step); position: absolute; top: -6px; left: 50%; z-index: 1; margin-left: -40px;
      display: grid; place-items: center; width: 20px; height: 20px; border-radius: 50%;
      background: #0b63ce; color: #ffffff; font-family: var(--font-mono); font-size: 11px; font-weight: 800; line-height: 1;
      box-shadow: 0 0 0 2px var(--page);
    }
    aside.research-side .reading-guide-list .side-illust {
      position: relative; max-width: 72px; border-radius: 50%; background: #02080d;
      box-shadow: 0 0 0 3px var(--page), 0 0 0 4px rgba(var(--ink-rgb), 0.2);
    }
    aside.research-side .reading-guide-list a:hover .side-illust { box-shadow: 0 0 0 3px var(--page), 0 0 0 4px var(--signal); }
    @media (prefers-reduced-motion: reduce) {
      aside.research-side .book-door-cover img,
      aside.research-side .research-doors .ai2040-project .side-illust img,
      aside.research-side .research-doors .translation-archive .side-illust img { transition: none; }
    }
    @media (max-width: 899px) {
      aside.research-side .research-side-title { font-size: 18px; }
      aside.research-side .reading-guide-list a::before { margin-left: -38px; }
    }
    .catalog-feature { min-width: 0; }
    .catalog-feature { overflow: hidden; }
    .research-main .theme-guide { margin-top: 40px; }
    .catalog-feature { list-style: none; grid-column: 1 / -1; padding: 18px 12px; border-right: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
    .catalog-feature .research-side { margin-top: 0; }
    @media (min-width: 560px) and (max-width: 899px) {
      .catalog-feature .research-side { grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 16px; }
      .catalog-feature .research-side-title { grid-column: 1 / -1; }
    }
    .catalog-feature[hidden] { display: none; }

    @media (min-width: 900px) {
      main, .site-footer { max-width: 1560px; }
      main { width: min(100%, 1560px); }
      .research-layout { display: grid; grid-template-columns: minmax(0, 1fr) clamp(220px, 20vw, 296px); gap: clamp(20px, 2.4vw, 36px); align-items: start; }
      .research-main .archive-list { grid-template-columns: repeat(3, minmax(0, 1fr)); }
      /* 特集列は中で別にスクロールさせず、全体を見せる。画面より高いときは、下端まで読み進めたところで止まる（topはスクリプトが高さから決める）。 */
      .research-layout > .research-side { position: sticky; top: 88px; margin-top: 0; }
    }
    @media (min-width: 900px) and (max-width: 1180px) {
      .research-main .archive-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    }