/* ============================
   kesson-space main.css
   extracted from index.html <style> tag
   ============================ */
    /* --- Bootstrapリセットの上書き: 本体UIを保護 --- */
    body {
      margin: 0;
      padding: 0;
      overflow-x: hidden;
      overflow-y: auto;
      background: var(--color-bg-body);
      font-family: var(--kesson-font-serif-display);
    }

    :root {
      /* === Color tokens === */
      --color-accent: 100, 150, 255;
      --color-sub-text: 180, 200, 230;
      --color-highlight: 220, 230, 245;
      --color-link: 130, 170, 255;
      --color-heading: 255, 255, 255;
      --color-bg-body: #050508;

      /* === Typography tokens === */
      --kesson-font-serif-display: "Noto Serif JP", "Yu Mincho", "MS PMincho", serif;
      --kesson-font-serif-ui: 'Georgia', "Noto Serif JP", serif;
      --kesson-font-mono-ui: 'SF Mono', 'Fira Code', 'Consolas', monospace;
      --kesson-font-size-ui-xs: clamp(0.4rem, 1.8vmin, 0.65rem);
      --kesson-font-size-ui-sm: clamp(0.5rem, 2.2vmin, 0.7rem);
      --kesson-font-size-ui-arrow: clamp(0.7rem, 3.5vmin, 1.2rem);
      --kesson-letter-ui-tight: 0.03em;
      --kesson-letter-ui-normal: 0.06em;
      --kesson-letter-ui-wide: 0.1em;
      --kesson-letter-ui-heading: 0.15em;

      /* === Motion/shape tokens === */
      --kesson-radius-sm: 2px;
      --kesson-radius-md: 3px;
      --kesson-radius-lg: 4px;
      --kesson-transition-standard: 0.3s ease;
      --kesson-transition-snappy: 0.2s ease;

      /* === Component surface tokens === */
      --kesson-focus-ring: rgba(var(--color-accent), 0.86);
      --kesson-focus-ring-soft: rgba(var(--color-accent), 0.8);
      --kesson-ui-label-color: rgba(var(--color-sub-text), 0.3);
      --kesson-ui-arrow-color: rgba(var(--color-sub-text), 0.25);
      --kesson-ui-label-hover-color: rgba(var(--color-sub-text), 0.6);
      --kesson-action-bg: rgba(var(--color-accent), 0.1);
      --kesson-action-border: rgba(var(--color-accent), 0.2);
      --kesson-action-text: rgba(var(--color-sub-text), 0.5);
      --kesson-action-bg-hover: rgba(var(--color-accent), 0.2);
      --kesson-action-text-hover: rgba(var(--color-highlight), 0.7);
      --kesson-card-border: rgba(var(--color-accent), 0.1);
      --kesson-card-border-strong: rgba(var(--color-accent), 0.28);
      --kesson-card-shadow-soft: 0 4px 12px rgba(var(--color-accent), 0.15);
      --kesson-card-shadow-rich: 0 8px 24px rgba(0, 0, 0, 0.38), 0 0 12px rgba(var(--color-accent), 0.15);
      --kesson-error-color: #f87171;
      --kesson-error-size: 0.8rem;
      --kesson-scrollbar-thumb: #1e293b;

      /* === Viewer/offcanvas tokens === */
      --kesson-offcanvas-text: #94a3b8;
      --kesson-offcanvas-heading: #e2e8f0;
      --kesson-offcanvas-link: #f59e0b;
      --kesson-viewer-overlay-closed: rgba(5, 10, 20, 0);
      --kesson-viewer-overlay-open: rgba(5, 10, 20, 0.5);
      --kesson-viewer-glass-bg: rgba(12, 18, 30, 0.88);
      --kesson-viewer-glass-border: rgba(var(--color-accent), 0.06);

      /* === Markdown tokens === */
      --kesson-md-provenance: rgba(140, 160, 200, 0.4);
      --kesson-md-h1: rgba(240, 245, 255, 0.92);
      --kesson-md-h1-strong: rgba(240, 245, 255, 0.95);
      --kesson-md-h2: rgba(230, 240, 255, 0.88);
      --kesson-md-h3: rgba(220, 230, 250, 0.85);
      --kesson-md-h4: rgba(210, 225, 245, 0.8);
      --kesson-md-link: rgba(var(--color-link), 0.85);
      --kesson-md-link-hover: rgba(160, 195, 255, 1);
      --kesson-md-quote: rgba(200, 215, 240, 0.7);
      --kesson-md-inline-code: rgba(180, 210, 255, 0.85);
      --kesson-md-inline-code-bg: rgba(60, 90, 150, 0.12);
      --kesson-md-table-head-bg: rgba(40, 60, 100, 0.2);
      --kesson-md-table-head-text: rgba(220, 230, 250, 0.9);
      --kesson-md-table-cell-text: rgba(200, 215, 240, 0.75);

      /* === Dev panel tokens === */
      --kesson-dev-toggle-bg: rgba(20, 30, 50, 0.7);
      --kesson-dev-toggle-bg-hover: rgba(30, 45, 70, 0.82);
      --kesson-dev-toggle-border: rgba(var(--color-accent), 0.15);

      /* === Layout tokens === */
      --kesson-section-content-padding: 1rem 1.5rem 0;
      --kesson-section-grid-margin-top: 1.5rem;
      --kesson-card-bg: rgba(20, 25, 40, 0.9);
      --kesson-offcanvas-width: 85%;
      --kesson-offcanvas-bg: rgba(10, 14, 26, 0.98);

      /* === Topbar tokens === */
      --ks-topbar-main-title-size: clamp(0.96rem, 1.85vw, 1.38rem);
      --ks-topbar-main-title-size-sm: 0.86rem;
      --ks-topbar-title-size: clamp(0.75rem, 1.0vw, 0.88rem);
      --ks-topbar-subtitle-size: var(--ks-topbar-title-size);
      --ks-topbar-subtitle-size-md: 0.66rem;
      --ks-topbar-link-size: 0.80rem;
      --ks-topbar-note-size: 0.80rem;
      --ks-topbar-note-size-sm: var(--ks-topbar-note-size);
      --ks-topbar-credit-size: 0.64rem;
      --ks-topbar-meta-size: clamp(0.68rem, 0.88vw, 0.76rem);
      --ks-topbar-meta-author-size: 0.68rem;
      --ks-topbar-bg-start: rgba(10, 14, 24, var(--kesson-topbar-alpha-strong));
      --ks-topbar-bg-end: rgba(10, 14, 24, var(--kesson-topbar-alpha-soft));
      --ks-topbar-border-color: rgba(130, 170, 240, var(--kesson-topbar-border-alpha));
      --ks-topbar-divider-color: rgba(170, 192, 228, 0.42);
      --ks-topbar-title-color: rgba(228, 238, 255, 0.92);
      --ks-topbar-title-hover-color: rgba(242, 248, 255, 1);
      --ks-topbar-subtitle-color: rgba(205, 220, 244, 0.76);
      --ks-topbar-meta-color: rgba(186, 204, 234, 0.72);
      --ks-topbar-meta-author-color: rgba(184, 203, 234, 0.74);
      --ks-topbar-link-color: rgba(205, 220, 244, 0.78);
      --ks-topbar-link-hover-color: rgba(236, 244, 255, 0.98);
      --ks-topbar-link-hover-bg: rgba(120, 165, 240, 0.2);
      --ks-topbar-note-divider-color: rgba(130, 170, 240, 0.2);
      --ks-topbar-note-color: rgba(165, 214, 255, 0.74);
      --ks-topbar-lang-color: rgba(218, 232, 255, 0.9);
      --ks-topbar-lang-border: rgba(130, 170, 240, 0.25);
      --ks-topbar-lang-bg: rgba(70, 102, 160, 0.16);
      --ks-topbar-nav-bg: rgba(9, 13, 24, 0.82);
      --ks-topbar-nav-border: rgba(130, 170, 240, 0.2);
      --ks-topbar-toggler-border: rgba(145, 178, 242, 0.55);
      --ks-topbar-toggler-focus: rgba(140, 180, 252, 0.35);

      --kesson-topbar-height: 3.25rem;
      --kesson-topbar-alpha-strong: 0.10;
      --kesson-topbar-alpha-soft: 0.10;
      --kesson-topbar-border-alpha: 0.22;
      --kesson-topbar-shadow-alpha: 0.26;
      --kesson-topbar-blur: 14px;
      --kesson-topbar-saturate: 145%;
    }
    
    #canvas-container {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      z-index: 1;
    }

    /* ============================
       Top menu bar (Bootstrap navbar)
       ============================ */
    #kesson-topbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      min-height: var(--kesson-topbar-height);
      z-index: 60;
      background: linear-gradient(
        to bottom,
        var(--ks-topbar-bg-start) 0%,
        var(--ks-topbar-bg-end) 100%
      );
      border-bottom: 1px solid var(--ks-topbar-border-color);
      box-shadow: 0 10px 24px rgba(0, 0, 0, var(--kesson-topbar-shadow-alpha));
      backdrop-filter: blur(var(--kesson-topbar-blur)) saturate(var(--kesson-topbar-saturate));
      -webkit-backdrop-filter: blur(var(--kesson-topbar-blur)) saturate(var(--kesson-topbar-saturate));
      padding-top: 0;
      padding-bottom: 0;
    }
    #kesson-topbar .container-fluid {
      min-height: var(--kesson-topbar-height);
    }
    #kesson-topbar .topbar-brand-wrap {
      display: flex;
      align-items: baseline;
      gap: 0.52rem;
      min-width: 0;
      max-width: calc(100% - 3rem);
      white-space: nowrap;
      overflow: hidden;
      padding: 0.24rem 0;
    }
    #kesson-topbar .topbar-main-title {
      color: var(--ks-topbar-title-color);
      font-family: var(--kesson-font-serif-display);
      font-size: var(--ks-topbar-main-title-size);
      letter-spacing: 0.04em;
      line-height: 1;
      text-transform: none;
      margin: 0;
      padding: 0;
      text-decoration: none;
      flex: 0 0 auto;
    }
    #kesson-topbar .topbar-main-title:hover,
    #kesson-topbar .topbar-main-title:focus-visible {
      color: var(--ks-topbar-title-hover-color);
    }
    #kesson-topbar .topbar-collab-note--brand {
      display: inline-block;
      margin-left: 0.1rem;
      padding-left: 0.5rem;
      border-left: 1px solid var(--ks-topbar-note-divider-color);
      max-width: 24rem;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      flex: 0 1 auto;
    }
    #kesson-topbar .topbar-subtitle {
      font-size: var(--ks-topbar-subtitle-size);
      color: var(--ks-topbar-subtitle-color);
      letter-spacing: 0.1em;
      line-height: 1;
      text-transform: none;
      flex: 0 0 auto;
      pointer-events: none;
    }
    #kesson-topbar .topbar-subtitle::before,
    #kesson-topbar .topbar-meta::before {
      content: '·';
      color: var(--ks-topbar-divider-color);
      margin-right: 0.45rem;
    }
    #kesson-topbar .topbar-meta {
      display: block;
      flex: 0 0 auto;
      padding: 0;
      font-size: var(--ks-topbar-meta-size);
      line-height: 1;
      letter-spacing: 0.05em;
      color: var(--ks-topbar-meta-color);
      font-family: var(--kesson-font-serif-ui);
      pointer-events: none;
    }
    #kesson-topbar .topbar-meta--author {
      font-size: var(--ks-topbar-meta-author-size);
      color: var(--ks-topbar-meta-author-color);
    }
    #kesson-topbar .topbar-link {
      color: var(--ks-topbar-link-color);
      font-family: var(--kesson-font-mono-ui);
      font-size: var(--ks-topbar-link-size);
      letter-spacing: 0.14em;
      text-transform: uppercase;
      padding: 0.4rem 0.72rem;
      border-radius: 999px;
      transition: color 0.25s ease, background-color 0.25s ease;
    }
    #kesson-topbar .topbar-link:hover,
    #kesson-topbar .topbar-link:focus-visible {
      color: var(--ks-topbar-link-hover-color);
      background: var(--ks-topbar-link-hover-bg);
    }
    #kesson-topbar .topbar-link-btn {
      border: 0;
      background: transparent;
      line-height: inherit;
      width: 100%;
      text-align: left;
    }
    #kesson-topbar .topbar-lang-btn {
      color: var(--ks-topbar-lang-color);
      border: 1px solid var(--ks-topbar-lang-border);
      background: var(--ks-topbar-lang-bg);
    }
    #kesson-topbar .topbar-collab-item {
      margin-left: 0.45rem;
      padding-left: 0.55rem;
      border-left: 1px solid var(--ks-topbar-note-divider-color);
    }
    #kesson-topbar .topbar-collab-note {
      display: inline-block;
      font-family: var(--kesson-font-serif-ui);
      font-size: var(--ks-topbar-note-size);
      line-height: 1;
      letter-spacing: 0.06em;
      color: var(--ks-topbar-note-color);
      white-space: nowrap;
      pointer-events: none;
      user-select: none;
    }
    #kesson-topbar .topbar-toggler {
      border-color: var(--ks-topbar-toggler-border);
      padding: 0.18rem 0.44rem;
    }
    #kesson-topbar .topbar-toggler:focus {
      box-shadow: 0 0 0 0.14rem var(--ks-topbar-toggler-focus);
    }
    #kessonTopbarNav {
      margin-top: 0.35rem;
      padding: 0.35rem 0.2rem 0.5rem;
      border-radius: 0.6rem;
      background: var(--ks-topbar-nav-bg);
      border: 1px solid var(--ks-topbar-nav-border);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
    }
    @media (min-width: 768px) {
      #kessonTopbarNav {
        margin-top: 0;
        padding: 0;
        background: transparent;
        border: 0;
        backdrop-filter: none;
        -webkit-backdrop-filter: none;
      }
      #kesson-topbar .topbar-link-btn {
        width: auto;
        text-align: center;
      }
      #kesson-topbar .topbar-lang-item {
        margin-left: 0.35rem;
      }
    }
    @media (max-width: 991.98px) {
      #kesson-topbar .topbar-meta--author {
        display: none;
      }
      #kesson-topbar .topbar-subtitle {
        font-size: var(--ks-topbar-subtitle-size-md);
      }
      #kesson-topbar .topbar-collab-item {
        margin-left: 0.3rem;
        padding-left: 0.45rem;
      }
    }
    @media (max-width: 767.98px) {
      #kesson-topbar .topbar-subtitle {
        display: none;
      }
      #kesson-topbar .topbar-main-title {
        font-size: var(--ks-topbar-main-title-size-sm);
      }
      #kesson-topbar .topbar-collab-note--brand {
        max-width: 10.5rem;
        padding-left: 0.38rem;
        font-size: var(--ks-topbar-credit-size);
        letter-spacing: 0.04em;
      }
      #kesson-topbar .topbar-collab-item {
        margin-left: 0;
        padding: 0.28rem 0.76rem 0 0.76rem;
        border-left: 0;
      }
      #kesson-topbar .topbar-collab-note {
        font-size: var(--ks-topbar-note-size-sm);
        letter-spacing: 0.05em;
      }
    }

    /* ============================
       nav-label (3Dナビラベル)
       ============================ */
    .nav-label {
      position: fixed;
      z-index: 15;
      pointer-events: auto;
      cursor: pointer;
      background: none;
      border: none;
      padding: 0;
      color: rgba(var(--color-heading), 0.9);
      font-family: "Noto Serif JP", "Yu Mincho", "MS PMincho", serif;
      font-size: clamp(0.45rem, 2.8vmin, 1.1rem);
      letter-spacing: clamp(0.05em, 0.4vmin, 0.15em);
      text-shadow: 0 0 12px rgba(var(--color-accent), 0.5), 0 0 4px rgba(0, 0, 0, 0.8);
      transform: translate(-50%, -100%);
      white-space: nowrap;
      transition: filter 0.15s ease, opacity 0.3s ease, color 0.3s ease, text-shadow 0.3s ease;
      will-change: filter;
    }
    .nav-label:hover {
      filter: blur(0px) !important;
      color: rgba(var(--color-heading), 1.0);
    }
    .nav-label:focus-visible,
    .nav-label.is-nav-focused {
      outline: 2px solid var(--kesson-focus-ring);
      outline-offset: 4px;
      filter: blur(0px) !important;
      text-shadow: 0 0 18px rgba(110, 160, 255, 0.72), 0 0 6px rgba(0, 0, 0, 0.85);
    }
    .nav-label--gem {
      color: rgba(180, 195, 240, 0.85);
      text-shadow: 0 0 12px rgba(123, 143, 232, 0.5), 0 0 4px rgba(0, 0, 0, 0.8);
    }
    .nav-label--gem:hover,
    .nav-label--gem:focus-visible,
    .nav-label--gem.is-nav-focused {
      color: rgba(200, 215, 255, 1.0);
    }
    .nav-label--x {
      color: rgba(220, 225, 240, 0.85);
      text-shadow: 0 0 12px rgba(180, 190, 220, 0.5), 0 0 4px rgba(0, 0, 0, 0.8);
      font-weight: bold;
      font-size: clamp(0.58rem, 3.2vmin, 1.28rem);
      letter-spacing: 0.03em;
      text-transform: uppercase;
    }
    .nav-label--x:hover,
    .nav-label--x:focus-visible,
    .nav-label--x.is-nav-focused {
      color: rgba(240, 245, 255, 1.0);
    }

    /* ============================
       左下: オーバーレイ（taglines）
       ============================ */
    #overlay {
      position: fixed;
      bottom: 8%;
      left: 5%;
      z-index: 10;
      pointer-events: none;
      text-align: left;
      opacity: 0.1;
      filter: blur(3px);
      transform: scale(0.95);
      transform-origin: left bottom;
      will-change: opacity, filter, transform;
    }
    
    #overlay a {
      pointer-events: auto;
      text-decoration: none;
      color: inherit;
    }

    /* ============================
       h1 / subtitle — 白くクッキリ
       ============================ */
    h1 {
      color: rgba(var(--color-heading), 0.95);
      font-family: "Noto Serif JP", "Yu Mincho", "MS PMincho", serif;
      font-weight: 400;
      font-size: clamp(1.0rem, 5.5vmin, 2.0rem);
      letter-spacing: clamp(0.15em, 1.2vmin, 0.5em);
      line-height: 1.6;
      margin-bottom: 0.6rem;
      text-shadow: 0 0 30px rgba(var(--color-accent), 0.3);
      transition: color 0.4s ease;
    }

    .subtitle {
      color: rgba(var(--color-heading), 0.85);
      font-family: var(--kesson-font-serif-ui);
      font-size: clamp(0.6rem, 3.5vmin, 1.3rem);
      letter-spacing: clamp(0.1em, 0.8vmin, 0.3em);
      line-height: 1.5;
      margin-top: 0;
      font-weight: normal;
      text-shadow: 0 0 30px rgba(var(--color-accent), 0.3);
    }

    #overlay a:hover h1 {
      color: rgba(var(--color-heading), 1.0);
    }

    #taglines {
      margin-bottom: 1rem;
    }

    /* CHANGED(2026-03-07): #114 — CSS変数化で font-size-ctrl から可変（clamp はフォールバック） */
    .tagline {
      font-size: var(--ks-overlay-tagline, 0.85rem);
      color: rgba(var(--color-heading), 0.75);
      font-family: "Noto Serif JP", "Yu Mincho", "MS PMincho", serif;
      letter-spacing: 0.05em;
      line-height: 1.8;
      text-shadow: 0 0 30px rgba(var(--color-accent), 0.3);
    }

    .tagline-en {
      font-size: var(--ks-overlay-tagline-en, 0.78rem);
      color: rgba(var(--color-heading), 0.55);
      font-family: var(--kesson-font-serif-ui);
      letter-spacing: 0.03em;
      line-height: 1.6;
      text-shadow: 0 0 30px rgba(var(--color-accent), 0.3);
    }

    /* ============================
       英語オーバーライド
       ============================ */
    html[lang="en"] h1 {
      font-size: clamp(0.85rem, 5.0vmin, 1.8rem);
      letter-spacing: clamp(0.05em, 0.4vmin, 0.15em);
      line-height: 1.3;
      margin-bottom: 0.4rem;
      font-family: var(--kesson-font-serif-ui);
    }

    html[lang="en"] .subtitle {
      font-size: clamp(0.5rem, 3.0vmin, 1.1rem);
      letter-spacing: clamp(0.06em, 0.3vmin, 0.1em);
      line-height: 1.3;
      font-family: var(--kesson-font-serif-ui);
    }

    html[lang="en"] #taglines {
      margin-bottom: 0.8rem;
    }

    /* ============================
       モバイル横 (landscape short)
       — vmin で自動縮小されるが、追加微調整
       ============================ */
    @media (max-height: 500px) and (orientation: landscape) {
      #taglines {
        margin-bottom: 0.4rem;
      }
      #overlay {
        bottom: 6%;
      }
    }

    /* --- 潜水スペーサー（スクロール余白） --- */
    #hero-spacer {
      position: relative;
      height: 125vh;
      z-index: 5;
      pointer-events: none;
    }
    /* --- Articles出現タイミング用スペーサー --- */
    #articles-spacer {
      position: relative;
      height: 80vh;
      z-index: 5;
      pointer-events: none;
    }

    /* ============================
       スクロール案内 — 共通パターン
       デフォルト非表示、.visible で表示+アニメ開始
       ============================ */

    /* --- 下部 scroll hint --- */
    #scroll-hint {
      position: fixed;
      bottom: 16px;
      left: 50%;
      transform: translateX(-50%);
      z-index: 15;
      text-align: center;
      pointer-events: none;
      opacity: 0;
      visibility: hidden;
      transition: opacity 0.6s ease, visibility 0.6s ease;
    }
    #scroll-hint.visible {
      opacity: 1;
      visibility: visible;
      animation: scrollHintPulse 3s ease-in-out infinite;
    }
    #scroll-hint span {
      margin-bottom: 4px;
    }
    @keyframes scrollHintPulse {
      0%, 100% { transform: translateX(-50%) translateY(0); }
      50% { transform: translateX(-50%) translateY(4px); }
    }

    /* --- 上部 scroll hint --- */
    #scroll-hint-top {
      position: fixed;
      top: calc(var(--kesson-topbar-height) + 6px);
      left: 50%;
      transform: translateX(-50%);
      z-index: 20;
      text-align: center;
      cursor: pointer;
      opacity: 0;
      visibility: hidden;
      pointer-events: none;
      transition: opacity 0.6s ease, visibility 0.6s ease;
    }
    #scroll-hint-top.visible {
      opacity: 1;
      visibility: visible;
      pointer-events: auto;
      animation: scrollHintTopPulse 3s ease-in-out infinite;
    }
    #scroll-hint-top span {
      margin-top: 4px;
    }
    @keyframes scrollHintTopPulse {
      0%, 100% { transform: translateX(-50%) translateY(0); }
      50% { transform: translateX(-50%) translateY(-4px); }
    }

    /* Lightweight directional UI (scroll hints) */
    #scroll-hint span,
    #scroll-hint-top span {
      display: block;
      font-size: var(--kesson-font-size-ui-xs);
      color: var(--kesson-ui-label-color);
      font-family: var(--kesson-font-serif-ui);
      letter-spacing: var(--kesson-letter-ui-wide);
    }
    #scroll-hint .arrow,
    #scroll-hint-top .arrow {
      font-size: var(--kesson-font-size-ui-arrow);
      color: var(--kesson-ui-arrow-color);
    }

    /* ============================
       操作ガイド（右上、言語トグルの下）
       ============================ */
    #control-guide {
      position: fixed;
      top: calc(var(--kesson-topbar-height) + 2.1rem);
      right: 3%;
      z-index: 10;
      pointer-events: none;
      text-align: right;
      transition: opacity 0.6s ease;
    }
    #control-guide .guide-row {
      display: flex;
      align-items: baseline;
      justify-content: flex-end;
      gap: 0.5em;
      margin-bottom: 3px;
    }
    /* CHANGED(2026-03-07): #114 — CSS変数化で font-size-ctrl から可変（clamp はフォールバック） */
    #control-guide .guide-key {
      font-size: var(--ks-control-guide, 0.75rem);
      color: rgba(var(--color-sub-text), 0.35);
      font-family: var(--kesson-font-mono-ui);
      letter-spacing: var(--kesson-letter-ui-tight);
      white-space: nowrap;
    }
    #control-guide .guide-sep {
      font-size: clamp(0.3rem, 1.4vmin, 0.5rem);
      color: rgba(var(--color-sub-text), 0.2);
    }
    #control-guide .guide-action {
      font-size: var(--ks-control-guide, 0.75rem);
      color: rgba(var(--color-sub-text), 0.3);
      font-family: var(--kesson-font-serif-ui);
      letter-spacing: var(--kesson-letter-ui-normal);
      white-space: nowrap;
    }
    /* タッチデバイス用: デスクトップ版を隠す */
    #control-guide .guide-touch { display: none; }
    #control-guide .guide-desktop { display: flex; }
    @media (hover: none) and (pointer: coarse) {
      #control-guide .guide-touch { display: flex; }
      #control-guide .guide-desktop { display: none; }
    }

    /* ============================
       Devlog Gallery (3D cards) — 透明背景
       ============================ */
    #devlog-gallery-section {
      width: 100%;
      background: transparent;
      padding-bottom: 2rem;
    }
    #devlog-gallery-container {
      position: relative;
      width: 100%;
    }
    /* devlog gallery container — ナビバーとの間隔 */
    #devlog-gallery-container > .container {
      margin-top: var(--kesson-section-grid-margin-top);
    }
    #guides-feature-cards,
    #articles-grid {
      margin-top: var(--kesson-section-grid-margin-top);
    }
    #devlog-gallery-header {
      position: fixed;
      top: calc(var(--kesson-topbar-height) + 8px);
      left: 24px;
      z-index: 20;
      pointer-events: none;
      opacity: 0;
      transition: opacity 0.4s ease;
    }
    #devlog-gallery-header.is-visible {
      opacity: 1;
    }
    /* CHANGED(2026-03-07): #114 — CSS変数化で font-size-ctrl から可変 */
    #devlog-gallery-header h2,
    .section-heading {
      /* CHANGED(2026-03-07): #116 Bug #9 — デフォルト +3 step (0.75+0.3=1.05) */
      font-size: var(--ks-section-heading, 1.05rem);
      font-weight: 400;
      color: var(--kesson-action-text);
      letter-spacing: var(--kesson-letter-ui-heading);
      text-transform: uppercase;
      margin: 0;
      font-family: var(--kesson-font-mono-ui);
    }

    /* Action controls */
    .btn-read-more,
    .articles-filter-btn,
    #surface-btn {
      background: var(--kesson-action-bg);
      border: 1px solid var(--kesson-action-border);
      color: var(--kesson-action-text);
      font-family: var(--kesson-font-serif-ui);
      cursor: pointer;
      border-radius: var(--kesson-radius-sm);
    }
    .btn-read-more:hover,
    .articles-filter-btn:hover,
    #surface-btn:hover {
      background: var(--kesson-action-bg-hover);
      color: var(--kesson-action-text-hover);
    }
    .btn-read-more:focus-visible,
    .articles-filter-btn:focus-visible,
    #surface-btn:focus-visible {
      outline: 2px solid var(--kesson-focus-ring-soft);
      outline-offset: 4px;
    }

    /* Read Moreボタン */
    .btn-read-more {
      font-size: var(--kesson-font-size-ui-sm);
      letter-spacing: var(--kesson-letter-ui-wide);
      padding: 10px 24px;
      transition: background var(--kesson-transition-standard), color var(--kesson-transition-standard);
    }

    /* Articles filter buttons (offcanvas) */
    .articles-filter-group {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
    }
    .articles-filter-btn {
      font-size: clamp(0.5rem, 2.1vmin, 0.66rem);
      letter-spacing: 0.08em;
      text-transform: uppercase;
      padding: 7px 14px;
      transition:
        background var(--kesson-transition-standard),
        color var(--kesson-transition-standard),
        border-color var(--kesson-transition-standard);
    }
    .articles-filter-btn.is-active {
      background: rgba(var(--color-accent), 0.25);
      border-color: rgba(120, 170, 255, 0.6);
      color: rgba(var(--color-highlight), 0.85);
    }

    /* === 共通カード (ARTICLES / CREATION CARDS 共通スタイル) === 
       カードのスタイル（透過度、ぼかし等）はサイト全体で統一すること */
    .card.kesson-card,
    .creation-link-card {
      --bs-card-bg: var(--kesson-card-bg);
      border: 1px solid var(--kesson-card-border);
      transition:
        transform var(--kesson-transition-snappy),
        box-shadow var(--kesson-transition-snappy),
        border-color var(--kesson-transition-snappy);
    }
    .card.kesson-card {
      background-color: var(--bs-card-bg);
      background-image: none;
      cursor: pointer;
    }
    .card.kesson-card:hover,
    .creation-link-card:hover {
      transform: translateY(-2px);
    }
    .card.kesson-card:hover {
      box-shadow: var(--kesson-card-shadow-soft);
    }
    .card.kesson-card:focus-visible,
    .creation-link-card:focus-visible {
      outline: 2px solid var(--kesson-focus-ring-soft);
      outline-offset: 4px;
    }
    .card.kesson-card .card-body {
      background-color: transparent;
    }
    .kesson-card .card-img-top {
      aspect-ratio: 16/9;
      object-fit: cover;
    }
    /* CHANGED(2026-03-07): #114 — CSS変数化で font-size-ctrl から可変 */
    .kesson-card .card-title {
      color: #fff;
      font-size: var(--ks-card-title, 1.1rem);
    }
    .kesson-card .card-body small {
      color: rgba(var(--color-heading), 0.5);
      font-size: var(--ks-card-text, 1.0rem);
    }
    .kesson-card .card-text {
      color: rgba(var(--color-heading), 0.5);
      font-size: var(--ks-card-text, 1.0rem);
    }
    .kesson-card .kesson-card-summary {
      color: rgba(var(--color-sub-text), 0.76);
      font-size: var(--ks-card-summary, 0.98rem);
      line-height: 1.45;
      display: -webkit-box;
      -webkit-box-orient: vertical;
      -webkit-line-clamp: 3;
      line-clamp: 3;
      overflow: hidden;
    }
    .kesson-card .kesson-card-cover-note {
      color: rgba(150, 190, 245, 0.72);
      font-size: 0.62rem;
      letter-spacing: 0.04em;
    }

    /* 無限スクロールローディング */
    #offcanvas-loading {
      text-align: center;
      padding: 20px;
      color: rgba(var(--color-sub-text), 0.5);
    }

    /* --- 浮上ボタン --- */
    #surface-btn {
      position: fixed;
      bottom: 24px;
      right: 24px;
      z-index: 20;
      /* CHANGED(2026-03-07): #116 Bug #8 — font-size-ctrl 連動 */
      font-size: var(--ks-surface-btn, 0.85rem);
      letter-spacing: var(--kesson-letter-ui-wide);
      padding: 10px 18px;
      opacity: 0;
      pointer-events: none;
      transition:
        opacity 0.6s ease,
        background var(--kesson-transition-standard),
        color var(--kesson-transition-standard);
    }

    /* ============================
       Offcanvas 詳細ビュー
       ============================ */
    .session-content {
      color: var(--kesson-offcanvas-text);
      font-family: var(--kesson-font-mono-ui);
    }
    .session-content h1,
    .session-content h2,
    .session-content h3 {
      color: var(--kesson-offcanvas-heading);
      margin-top: 1.5em;
      margin-bottom: 0.5em;
    }
    .session-content h1 { font-size: 1.3rem; }
    .session-content h2 { font-size: 1.1rem; }
    .session-content h3 { font-size: 0.95rem; }
    .session-content p {
      font-size: 0.85rem;
      line-height: 1.8;
      color: var(--kesson-offcanvas-text);
      margin-bottom: 1em;
      font-family: var(--kesson-font-serif-display);
    }
    .session-content ul,
    .session-content ol {
      font-size: 0.85rem;
      line-height: 1.8;
      color: var(--kesson-offcanvas-text);
      padding-left: 1.5em;
    }
    .session-content code {
      background: rgba(var(--color-accent), 0.1);
      padding: 0.15em 0.4em;
      border-radius: 3px;
      font-size: 0.8em;
    }
    .session-content pre {
      background: rgba(0, 0, 0, 0.3);
      padding: 1em;
      border-radius: 4px;
      overflow-x: auto;
    }
    .session-content a {
      color: var(--kesson-offcanvas-link);
    }
    .offcanvas-body::-webkit-scrollbar { width: 6px; }
    .offcanvas-body::-webkit-scrollbar-track { background: transparent; }
    .offcanvas-body::-webkit-scrollbar-thumb {
      background: var(--kesson-scrollbar-thumb);
      border-radius: var(--kesson-radius-md);
    }

    /* ============================
       T-018: Extracted from index.html inline styles
       CHANGED(2026-02-16)
       ============================ */

    /* Section containers */
    /* CHANGED(2026-03-07): #116 Bug #7 — guides-section を他セクションと統一 */
    #guides-section,
    #articles-section,
    #creation-cards-section,
    #devlog-gallery-section {
      position: relative;
      z-index: 5;
    }
    #creation-cards-section {
      padding-bottom: 2.2rem;
    }
    #creation-cards-grid {
      margin-top: var(--kesson-section-grid-margin-top);
    }

    /* Section content wrapper (shared by articles + devlog heading areas) */
    .section-content-wrap {
      position: relative;
      z-index: 20;
      padding: var(--kesson-section-content-padding);
    }

    .section-heading-link {
      appearance: none;
      background: transparent;
      border: 0;
      padding: 0;
      margin: 0;
      color: inherit;
      text-decoration: none;
      font: inherit;
      letter-spacing: inherit;
      text-transform: inherit;
      cursor: pointer;
    }

    .section-heading-link:visited,
    .section-heading-link:hover,
    .section-heading-link:active {
      text-decoration: none;
    }

    .section-heading-link:hover {
      color: rgba(200, 220, 250, 0.72);
    }

    .section-heading-link:focus-visible {
      outline: 1px solid rgba(150, 190, 255, 0.7);
      outline-offset: 4px;
    }

    #articles-error,
    #creation-cards-error {
      color: var(--kesson-error-color);
      font-size: var(--kesson-error-size);
    }

    .creation-link-card {
      overflow: hidden;
      background-color: rgba(20, 25, 40, 0.9) !important;
      backdrop-filter: none;
      -webkit-backdrop-filter: none;
    }
    .creation-link-card:hover {
      box-shadow: var(--kesson-card-shadow-rich);
      border-color: var(--kesson-card-border-strong);
    }
    .creation-link-card.is-coming-soon {
      cursor: default;
      border-style: dashed;
    }
    .creation-link-card.is-coming-soon:hover {
      transform: none;
      box-shadow: var(--kesson-card-shadow-soft);
      border-color: var(--kesson-card-border);
    }
    .creation-link-card.is-coming-soon small {
      color: rgba(var(--color-sub-text), 0.42);
    }
    .creation-card-thumb {
      aspect-ratio: 16 / 9;
      border-bottom: 1px solid rgba(var(--color-accent), 0.05);
      overflow: hidden;
      background: rgba(10, 15, 30, 0.6);
    }
    .creation-card-thumb-image {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }
    .creation-card-placeholder-thumb {
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .creation-card-placeholder-thumb::after {
      content: attr(data-label);
      font-size: 0.6rem;
      letter-spacing: 0.2em;
      color: rgba(var(--color-sub-text), 0.24);
      font-family: var(--kesson-font-mono-ui);
    }
    .creation-link-card .card-title {
      color: rgba(var(--color-highlight), 0.92);
      font-family: var(--kesson-font-serif-display);
      letter-spacing: 0.04em;
    }
    .creation-link-card .card-text {
      color: rgba(var(--color-sub-text), 0.64);
      line-height: 1.6;
    }

    /* Offcanvas panel — kesson dark theme */
    .offcanvas-kesson {
      --bs-offcanvas-width: var(--kesson-offcanvas-width);
      width: var(--kesson-offcanvas-width);
      background: var(--kesson-offcanvas-bg);
    }

    /* Offcanvas title letter spacing */
    .offcanvas-title-spaced {
      letter-spacing: 0.15em;
    }

    /* Cursor pointer utility */
    .cursor-pointer {
      cursor: pointer;
    }

    /* Lightbox image constraints */
    #lightbox-image {
      max-height: 80vh;
      cursor: pointer;
    }

    /* Article type badge — smaller font */
    .badge-article-type {
      font-size: 0.65rem;
    }

    /* ============================
       T-018: Extracted from viewer.js injectViewerStyles()
       CHANGED(2026-02-16)
       ============================ */

    #kesson-viewer {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      z-index: 200;
      display: none;
      align-items: center;
      justify-content: center;
      background: var(--kesson-viewer-overlay-closed);
      transition: background 0.5s ease;
      cursor: pointer;
    }
    #kesson-viewer.visible {
      display: flex;
    }
    #kesson-viewer.open {
      background: var(--kesson-viewer-overlay-open);
    }

    .viewer-glass {
      position: relative;
      width: 90vw;
      max-width: 720px;
      height: 85vh;
      cursor: default;
      overflow: hidden;
      background: var(--kesson-viewer-glass-bg);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border: 1px solid var(--kesson-viewer-glass-border);
      border-radius: var(--kesson-radius-md);
      box-shadow:
        0 0 60px rgba(0, 0, 0, 0.4),
        0 0 120px rgba(30, 60, 120, 0.1),
        inset 0 0 60px rgba(20, 40, 80, 0.05);
      opacity: 0;
      transform: scale(0.92) translateY(20px);
      transition: all 0.5s cubic-bezier(0.22, 1, 0.36, 1);
    }
    #kesson-viewer.open .viewer-glass {
      opacity: 1;
      transform: scale(1) translateY(0);
    }

    .viewer-close {
      position: static;
      background: none;
      border: none;
      color: rgba(var(--color-heading), 0.3);
      font-size: 1.3rem;
      cursor: pointer;
      width: 32px;
      height: 32px;
      flex-shrink: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: color var(--kesson-transition-standard);
      z-index: 10;
    }
    .viewer-close:hover {
      color: rgba(var(--color-heading), 0.7);
    }

    .viewer-content {
      width: 100%;
      height: 100%;
      overflow-y: auto;
      -webkit-overflow-scrolling: touch;
      flex: 1;
    }
    .viewer-content iframe {
      width: 100%;
      height: 100%;
      border: none;
      border-radius: var(--kesson-radius-md);
    }
    .viewer-content--x {
      display: flex;
      flex-direction: column;
      height: 100%;
    }
    .x-embed-wrap {
      flex: 1;
      display: flex;
      align-items: stretch;
    }
    .x-embed-wrap .twitter-timeline {
      width: 100%;
    }
    .x-embed-footer {
      padding: 0.5rem 1rem 0.9rem;
      text-align: center;
      font-size: 0.78rem;
    }
    .x-embed-handle {
      color: rgba(200, 215, 245, 0.7);
      font-size: 0.72rem;
      margin-bottom: 0.25rem;
      letter-spacing: 0.04em;
    }
    .x-embed-footer a {
      color: rgba(var(--color-link), 0.85);
      text-decoration: underline;
      text-underline-offset: 2px;
    }

    /* viewer scrollbar */
    .viewer-content::-webkit-scrollbar { width: 3px; }
    .viewer-content::-webkit-scrollbar-track { background: transparent; }
    .viewer-content::-webkit-scrollbar-thumb {
      background: rgba(var(--color-accent), 0.12);
      border-radius: 2px;
    }

    /* --- markdown article --- */
    .md-article {
      padding: 2.5rem 2rem 3rem;
      color: rgba(var(--color-highlight), 0.85);
      line-height: 1.85;
      font-size: 0.92rem;
    }

    /* provenance (generator info) */
    .md-provenance {
      font-size: 0.68rem;
      color: var(--kesson-md-provenance);
      margin-bottom: 1.5rem;
      letter-spacing: 0.03em;
    }

    .md-body p {
      margin: 0 0 1.2em;
    }
    .md-body h1 {
      font-size: 1.2rem;
      color: var(--kesson-md-h1);
      margin: 2rem 0 0.8rem;
      line-height: 1.4;
      letter-spacing: normal;
      text-shadow: none;
      border: none;
      page-break-before: unset;
    }
    .md-body h1:first-child {
      font-size: 1.3rem;
      color: var(--kesson-md-h1-strong);
      margin-top: 0;
      margin-bottom: 1.2rem;
    }
    .md-body h2 {
      font-size: 1.05rem;
      color: var(--kesson-md-h2);
      margin: 1.8rem 0 0.7rem;
      line-height: 1.4;
    }
    .md-body h3 {
      font-size: 0.95rem;
      color: var(--kesson-md-h3);
      margin: 1.4rem 0 0.5rem;
    }
    .md-body h4 {
      font-size: 0.9rem;
      color: var(--kesson-md-h4);
      margin: 1.2rem 0 0.4rem;
    }
    .md-body hr {
      border: none;
      border-top: 1px solid rgba(var(--color-accent), 0.08);
      margin: 2rem 0;
    }
    .md-body blockquote {
      border-left: 2px solid rgba(var(--color-accent), 0.15);
      padding-left: 1em;
      margin: 1em 0;
      color: var(--kesson-md-quote);
      font-style: italic;
    }
    .md-body a {
      color: var(--kesson-md-link);
      text-decoration: underline;
      text-underline-offset: 2px;
    }
    .md-body a:hover {
      color: var(--kesson-md-link-hover);
    }
    .md-body strong {
      color: rgba(240, 245, 255, 0.95);
      font-weight: 600;
    }
    .md-body em {
      color: var(--kesson-md-quote);
    }

    /* --- code blocks (marked.js output) --- */
    .md-body pre {
      background: rgba(8, 12, 24, 0.6);
      border: 1px solid rgba(var(--color-accent), 0.08);
      border-radius: var(--kesson-radius-md);
      padding: 1em 1.2em;
      margin: 1.2em 0;
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
      line-height: 1.5;
    }
    .md-body pre code {
      font-family: var(--kesson-font-mono-ui);
      font-size: 0.82rem;
      color: rgba(var(--color-sub-text), 0.8);
      background: none;
      padding: 0;
      border: none;
      border-radius: 0;
      white-space: pre;
    }
    .md-body code {
      font-family: var(--kesson-font-mono-ui);
      font-size: 0.85em;
      color: var(--kesson-md-inline-code);
      background: var(--kesson-md-inline-code-bg);
      padding: 0.15em 0.4em;
      border-radius: var(--kesson-radius-sm);
    }

    /* --- lists (marked.js output) --- */
    .md-body ul, .md-body ol {
      padding-left: 1.5em;
      margin: 0.8em 0;
    }
    .md-body li {
      margin-bottom: 0.4em;
      line-height: 1.7;
    }
    .md-body li > ul, .md-body li > ol {
      margin: 0.3em 0;
    }

    /* --- table (marked.js GFM output) --- */
    .md-body table {
      border-collapse: collapse;
      width: 100%;
      font-size: 0.82rem;
      margin: 1.2em 0;
      overflow-x: auto;
      display: block;
    }
    .md-body thead {
      border-bottom: 1px solid rgba(var(--color-accent), 0.15);
    }
    .md-body th, .md-body td {
      padding: 0.5em 0.8em;
      border: 1px solid rgba(var(--color-accent), 0.08);
      text-align: left;
    }
    .md-body th {
      background: var(--kesson-md-table-head-bg);
      color: var(--kesson-md-table-head-text);
      font-weight: 500;
    }
    .md-body td {
      color: var(--kesson-md-table-cell-text);
    }

    /* --- images --- */
    .md-body img {
      max-width: 100%;
      height: auto;
      border-radius: var(--kesson-radius-sm);
      margin: 1em 0;
    }

    /* ============================
       Viewer header bar（右上: PDF + MD + 閉じる）
       ============================ */
    .viewer-header {
      display: flex;
      align-items: center;
      justify-content: flex-end;
      gap: 0.5rem;
      padding: 0.6rem 1rem 0.6rem 1.2rem;
      border-bottom: 1px solid rgba(var(--color-accent), 0.08);
      flex-shrink: 0;
    }
    /* CHANGED(2026-03-06): #105 — modal タイトル */
    /* CHANGED(2026-03-07): #114 — font-size-ctrl topbar ボタン */
    /* CHANGED(2026-03-07): #116 — topbar-font-btn 0.6rem → 0.65rem */
    .topbar-font-size-ctrl {
      opacity: 0.75;
    }
    .topbar-font-btn {
      font-family: var(--kesson-font-mono-ui);
      font-size: 0.65rem;
      letter-spacing: 0.08em;
      padding: 0.2rem 0.5rem;
      background: transparent;
      border: 1px solid rgba(130, 170, 240, 0.2);
      color: rgba(205, 220, 244, 0.7);
      line-height: 1.4;
    }
    .topbar-font-btn:hover:not(:disabled) {
      background: rgba(120, 165, 240, 0.15);
      color: rgba(236, 244, 255, 0.9);
    }
    .topbar-font-btn:disabled {
      opacity: 0.3;
      cursor: default;
    }

    .viewer-title {
      flex: 1;
      font-size: 0.82rem;
      font-family: var(--kesson-font-mono-ui);
      color: rgba(200, 220, 255, 0.85);
      letter-spacing: 0.03em;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    .viewer-header-links {
      display: flex;
      align-items: center;
      gap: 0.4rem;
      flex-wrap: wrap;
    }
    .viewer-header-link {
      display: inline-flex;
      align-items: center;
      padding: 0.3em 0.85em;
      font-size: 0.72rem;
      font-family: var(--kesson-font-mono-ui);
      letter-spacing: 0.04em;
      color: rgba(160, 185, 240, 0.75);
      border: 1px solid rgba(var(--color-accent), 0.15);
      border-radius: var(--kesson-radius-sm);
      text-decoration: none;
      transition: all var(--kesson-transition-standard);
      white-space: nowrap;
    }
    .viewer-header-link:hover {
      color: rgba(210, 228, 255, 0.95);
      border-color: rgba(var(--color-accent), 0.3);
      background: rgba(60, 90, 150, 0.12);
    }
    .viewer-header-link--md {
      color: rgba(140, 170, 220, 0.6);
      border-color: rgba(var(--color-accent), 0.08);
      font-size: 0.67rem;
    }
    .viewer-header-link--md:hover {
      color: rgba(180, 210, 255, 0.85);
      border-color: rgba(var(--color-accent), 0.2);
    }
    /* viewer-glass をフレックス縦並びに変更 */
    .viewer-glass {
      display: flex !important;
      flex-direction: column;
    }
    .viewer-content {
      flex: 1;
      overflow-y: auto;
    }
    /* 旧 md-footer / md-pdf-link は非表示（念のため残す） */
    .md-footer { display: none; }
    .md-pdf-link { display: none; }

    /* loading */
    .md-loading {
      display: flex;
      align-items: center;
      justify-content: center;
      height: 100%;
    }
    .md-loading-dot {
      width: 6px;
      height: 6px;
      background: rgba(var(--color-link), 0.4);
      border-radius: 50%;
      animation: md-pulse 1.2s ease-in-out infinite;
    }
    @keyframes md-pulse {
      0%, 100% { opacity: 0.3; transform: scale(0.8); }
      50% { opacity: 1; transform: scale(1.2); }
    }

    /* viewer mobile */
    @media (max-width: 600px) {
      .viewer-glass {
        width: 96vw;
        height: 90vh;
        border-radius: var(--kesson-radius-sm);
      }
      .md-article {
        padding: 2rem 1.2rem 2.5rem;
        font-size: 0.88rem;
        line-height: 1.8;
      }
      .md-body h1:first-child { font-size: 1.1rem; }
      .md-body h1 { font-size: 1.05rem; }
      .md-body h2 { font-size: 0.95rem; }
      .md-body table { font-size: 0.75rem; }
      .md-body pre { padding: 0.8em; }
      .md-body pre code { font-size: 0.75rem; }
    }

    /* Hidden state for nav labels (camera behind / scroll fade) */
    .nav-label--hidden {
      opacity: 0 !important;
      pointer-events: none !important;
    }

    /* ============================
       T-018: Extracted from dev-panel.js
       CHANGED(2026-02-16)
       ============================ */

    #dev-toggle,
    #dev-links-toggle {
      position: fixed;
      right: 0;
      transform: translateY(-50%);
      z-index: 1001;
      background: var(--kesson-dev-toggle-bg);
      backdrop-filter: blur(8px);
      border: 1px solid var(--kesson-dev-toggle-border);
      border-right: none;
      border-radius: var(--kesson-radius-lg) 0 0 var(--kesson-radius-lg);
      font-family: var(--kesson-font-mono-ui);
      padding: 8px 5px;
      cursor: pointer;
      writing-mode: vertical-rl;
      transition: all var(--kesson-transition-standard);
    }
    #dev-toggle {
      top: 50%;
      color: rgba(180, 200, 255, 0.6);
      font-size: 0.65rem;
      letter-spacing: 0.15em;
    }
    #dev-links-toggle {
      top: calc(50% + 95px);
      color: rgba(180, 200, 255, 0.75);
      font-size: 0.62rem;
      letter-spacing: 0.1em;
    }
    #dev-toggle:hover,
    #dev-links-toggle:hover {
      background: var(--kesson-dev-toggle-bg-hover);
    }
    #dev-toggle:hover {
      color: rgba(200, 220, 255, 0.9);
    }
    #dev-links-toggle:hover {
      color: rgba(210, 225, 255, 0.95);
    }
    #dev-toggle.open { right: 300px; }

    #dev-panel {
      position: fixed;
      top: 0;
      right: -300px;
      width: 300px;
      height: 100%;
      z-index: 1000;
      overflow-y: auto;
      transition: right 0.35s cubic-bezier(0.22, 1, 0.36, 1);
      background: rgba(13, 17, 23, 0.95);
      backdrop-filter: blur(12px);
      border-left: 1px solid rgba(var(--color-accent), 0.1);
    }
    #dev-panel.open { right: 0; }
    #dev-panel::-webkit-scrollbar { width: 4px; }
    #dev-panel::-webkit-scrollbar-thumb {
      background: rgba(var(--color-accent), 0.2);
      border-radius: var(--kesson-radius-sm);
    }

    #dev-panel .accordion-button {
      padding: 0.5rem 0.75rem;
      font-size: 0.72rem;
      font-family: var(--kesson-font-mono-ui);
      letter-spacing: 0.05em;
      background: rgba(20, 28, 40, 0.9);
      color: rgba(140, 170, 220, 0.8);
      border: none;
      box-shadow: none;
    }
    #dev-panel .accordion-button:not(.collapsed) {
      background: rgba(30, 45, 70, 0.7);
      color: rgba(160, 190, 255, 0.9);
    }
    #dev-panel .accordion-button::after {
      filter: invert(0.6) sepia(1) saturate(2) hue-rotate(190deg);
    }
    #dev-panel .accordion-body {
      padding: 0.5rem 0.75rem;
      background: rgba(10, 15, 25, 0.8);
    }
    #dev-panel .accordion-item {
      background: transparent;
      border: none;
      border-bottom: 1px solid rgba(var(--color-accent), 0.06);
    }

    /* ============================
       Dev Links Hub (?dev)
       ============================ */
    .offcanvas-links {
      --bs-offcanvas-width: min(520px, 92vw);
      width: min(520px, 92vw);
    }

    #devLinksOffcanvas .nav-tabs {
      border-bottom-color: rgba(110, 140, 200, 0.35);
    }
    #devLinksOffcanvas .nav-tabs .nav-link {
      color: rgba(190, 210, 240, 0.75);
      border: 1px solid transparent;
      border-bottom: none;
    }
    #devLinksOffcanvas .nav-tabs .nav-link.active {
      color: rgba(220, 232, 255, 0.96);
      background: rgba(34, 44, 67, 0.78);
      border-color: rgba(110, 140, 200, 0.35);
    }

    .dev-links-item {
      background: rgba(14, 18, 30, 0.84);
      border-color: rgba(100, 140, 210, 0.24) !important;
    }
    .dev-links-key {
      font-size: 0.66rem;
      color: rgba(170, 190, 220, 0.7);
      font-family: var(--kesson-font-mono-ui);
      letter-spacing: 0.05em;
    }
    .dev-links-url {
      font-size: 0.68rem;
      color: rgba(153, 202, 255, 0.95);
      user-select: all;
      white-space: normal;
      word-break: break-all;
    }
    .dev-links-json-preview {
      max-height: 40vh;
      overflow: auto;
      border: 1px solid rgba(100, 140, 210, 0.24);
      border-radius: 0.35rem;
      background: rgba(12, 16, 26, 0.92);
      color: rgba(167, 214, 255, 0.9);
      padding: 0.75rem;
      font-size: 0.7rem;
    }

    #dev-panel .form-check {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.25rem 0;
      margin: 0;
    }
    #dev-panel .form-check-label {
      font-size: 0.68rem;
      font-family: var(--kesson-font-mono-ui);
      color: rgba(var(--color-sub-text), 0.7);
      order: -1;
      padding-left: 0;
    }
    #dev-panel .form-check-input {
      margin: 0;
      cursor: pointer;
    }

    .dev-slider-row { margin-bottom: 0.4rem; }
    .dev-slider-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 0.65rem;
      font-family: var(--kesson-font-mono-ui);
      color: rgba(var(--color-sub-text), 0.6);
      margin-bottom: 0.15rem;
    }
    .dev-slider-val {
      color: rgba(130, 200, 255, 0.9);
      min-width: 36px;
      text-align: right;
    }
    #dev-panel .form-range { height: 0.5rem; padding: 0; }
    #dev-panel .form-range::-webkit-slider-thumb {
      width: 12px; height: 12px;
      background: rgba(100, 160, 255, 0.8);
      border: 1px solid rgba(150, 200, 255, 0.3);
    }

    #dev-export-result {
      font-size: 0.58rem;
      max-height: 180px;
      overflow-y: auto;
      display: none;
      user-select: all;
    }

    /* Dev panel header text */
    .dev-panel-header-text {
      font-family: var(--kesson-font-mono-ui);
      letter-spacing: 0.1em;
    }

    /* Dev export button */
    .dev-export-btn {
      font-size: 0.68rem;
    }

    /* ============================
       Tech Stack Footer（左下、控えめ）
       ============================ */
    #tech-footer {
      position: relative;
      z-index: 5;
      text-align: left;
      padding: 2rem 3% 1.5rem;
      pointer-events: none;
    }
    /* CHANGED(2026-03-07): #114 — CSS変数化で font-size-ctrl から可変（clamp はフォールバック） */
    .tech-footer-line {
      font-size: var(--ks-footer-line, 0.75rem);
      color: rgba(150, 175, 210, 0.25);
      font-family: var(--kesson-font-mono-ui);
      letter-spacing: 0.06em;
      line-height: 1.8;
    }
    #footer-signature {
      margin-top: 0.28rem;
      color: rgba(178, 198, 228, 0.44);
      letter-spacing: 0.08em;
    }