/* ==========================================================================
   Tes-Lucky Tesla Q&A - 優しいモダン＆高視認性ライトテーマ (v2.1.0)
   デザイン思想:
   1. 清潔感・親しみやすさ・温かみのあるモダンライトUI
   2. 極上のフォントレンダリングと読みやすい行間・階層
   3. ミニマルな固定ナビ（高さ56px）でモバイルの可視領域を最大化
   4. Apple HIG準拠の44px以上の快適なタップターゲット
   5. WCAG AA準拠の高コントラスト＆完全レスポンシブ
   ========================================================================== */

:root {
    --bg-page: #f8fafc;
    --bg-card: #ffffff;
    --bg-subtle: #f1f5f9;
    --bg-subtle-hover: #e2e8f0;
    --border-color: #e2e8f0;
    --border-hover: #cbd5e1;
    --border-focus: #2563eb;

    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #475569;
    --text-light: #64748b;

    --accent-red: #e11d48;
    --accent-red-soft: #ffe4e6;
    --accent-blue: #2563eb;
    --accent-blue-soft: #dbeafe;
    --accent-blue-hover: #1d4ed8;
    --accent-emerald: #059669;
    --accent-emerald-soft: #d1fae5;
    --accent-amber: #d97706;
    --accent-amber-soft: #fef3c7;
    --accent-purple: #7c3aed;
    --accent-purple-soft: #ede9fe;

    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.08), 0 1px 2px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
    --shadow-hover: 0 12px 24px -4px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.04);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    --transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Hiragino Kaku Gothic ProN", sans-serif;
    background-color: var(--bg-page);
    color: var(--text-primary);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* スキップリンク（キーボードナビゲーション） */
.skip-link {
    position: absolute;
    top: -40px;
    left: 16px;
    background: var(--accent-blue);
    color: #ffffff;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 700;
    font-size: 0.9rem;
    z-index: 9999;
    transition: top 0.2s ease;
}
.skip-link:focus {
    top: 12px;
}

/* 優しい背景アクセント（グラデーション） */
.ambient-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    pointer-events: none;
    background: 
        radial-gradient(circle at 10% 12%, rgba(219, 234, 254, 0.5) 0%, transparent 45%),
        radial-gradient(circle at 90% 88%, rgba(254, 226, 226, 0.4) 0%, transparent 45%),
        radial-gradient(circle at 50% 50%, rgba(241, 245, 249, 0.6) 0%, transparent 70%);
}

/* =========================================
   固定ミニマルナビゲーション（Sticky Nav: 56px）
   ========================================= */
.sticky-nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-xs);
}

.nav-inner {
    max-width: 1240px;
    margin: 0 auto;
    padding: 10px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
}

.nav-brand {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 800;
    font-size: 1rem;
    padding: 6px 10px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    flex-shrink: 0;
}
.nav-brand:hover {
    background: var(--bg-subtle);
    color: var(--accent-blue);
}
.brand-icon {
    color: var(--accent-red);
    font-size: 1.1rem;
}
.brand-sub {
    font-size: 0.75rem;
    font-weight: 700;
    background: var(--accent-blue-soft);
    color: var(--accent-blue);
    padding: 2px 6px;
    border-radius: 4px;
    margin-left: 4px;
}

.nav-tools {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
}

.tool-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    min-height: 40px;
    border-radius: var(--radius-full);
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    white-space: nowrap;
}
.tool-chip:hover {
    background: #ffffff;
    border-color: var(--accent-blue);
    color: var(--accent-blue);
    box-shadow: var(--shadow-sm);
    transform: translateY(-1px);
}

/* =========================================
   ヒーローヘッダー（静的・自然にスクロール）
   ========================================= */
.hero-header {
    background: transparent;
    padding: 36px 20px 24px;
    text-align: center;
}

.hero-inner {
    max-width: 860px;
    margin: 0 auto;
}

.hero-badge-wrap {
    display: flex;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 12px;
}

.hero-pill {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: #ffffff;
    border: 1px solid var(--border-color);
    padding: 5px 12px;
    border-radius: var(--radius-full);
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 700;
    box-shadow: var(--shadow-xs);
}
.hero-pill.accent {
    background: var(--accent-blue-soft);
    border-color: #bfdbfe;
    color: var(--accent-blue);
}

.hero-title {
    font-size: 1.85rem;
    font-weight: 900;
    letter-spacing: -0.5px;
    color: #0f172a;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 10px;
}

.hero-desc {
    color: var(--text-secondary);
    font-size: 0.98rem;
    line-height: 1.7;
    max-width: 720px;
    margin: 0 auto;
}

/* =========================================
   メインコンテナ
   ========================================= */
.main-container {
    max-width: 1240px;
    width: 100%;
    margin: 0 auto;
    padding: 12px 20px 80px;
    flex-grow: 1;
}

/* =========================================
   検索セクション
   ========================================= */
.search-card {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 20px 24px;
    box-shadow: var(--shadow-md);
    margin-bottom: 20px;
    transition: var(--transition);
}
.search-card:focus-within {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.12), var(--shadow-md);
}

.search-input-wrap {
    position: relative;
    display: flex;
    align-items: center;
}

.search-input-wrap .search-icon {
    position: absolute;
    left: 16px;
    color: var(--text-light);
    font-size: 1.25rem;
    pointer-events: none;
    transition: var(--transition);
}

.search-input-wrap input {
    width: 100%;
    padding: 14px 48px 14px 48px;
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--text-primary);
    background: var(--bg-subtle);
    border: 1px solid transparent;
    border-radius: var(--radius-lg);
    outline: none;
    transition: var(--transition);
}
.search-input-wrap input:focus {
    background: #ffffff;
    border-color: var(--border-focus);
}
.search-input-wrap input:focus ~ .search-icon {
    color: var(--accent-blue);
}

.clear-search-btn {
    position: absolute;
    right: 12px;
    background: transparent;
    border: none;
    color: var(--text-light);
    font-size: 1.1rem;
    cursor: pointer;
    display: none;
    padding: 10px;
    border-radius: var(--radius-full);
    min-width: 44px;
    min-height: 44px;
    align-items: center;
    justify-content: center;
}
.clear-search-btn:hover {
    color: var(--text-primary);
    background: var(--bg-subtle);
}

/* おすすめクイック検索キーワード */
.quick-keywords {
    margin-top: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.quick-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 700;
}

.quick-btn {
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    min-height: 36px;
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
}
.quick-btn:hover {
    background: var(--accent-blue-soft);
    border-color: #93c5fd;
    color: var(--accent-blue);
}

/* =========================================
   大カテゴリ ピル・タブナビゲーション
   ========================================= */
.group-tabs-outer {
    position: relative;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
}

.tab-scroll-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-full);
    background: #ffffff;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    box-shadow: var(--shadow-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    transition: var(--transition);
}
.tab-scroll-btn:hover {
    background: var(--bg-subtle);
    color: var(--accent-blue);
}
.tab-scroll-btn.left { left: -6px; }
.tab-scroll-btn.right { right: -6px; }

.group-tabs-wrap {
    overflow-x: auto;
    scrollbar-width: thin;
    padding: 4px 6px;
    width: 100%;
    -webkit-overflow-scrolling: touch;
}
.group-tabs-wrap::-webkit-scrollbar {
    height: 6px;
}
.group-tabs-wrap::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 3px;
}

.group-tabs {
    display: flex;
    gap: 10px;
    min-width: max-content;
}

.group-tab-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    min-height: 44px;
    border-radius: var(--radius-full);
    background: #ffffff;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 700;
    cursor: pointer;
    box-shadow: var(--shadow-xs);
    transition: var(--transition);
    user-select: none;
}
.group-tab-btn:hover {
    border-color: var(--accent-blue);
    color: var(--accent-blue);
    transform: translateY(-1px);
}
.group-tab-btn.active {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.group-tab-btn .tab-count {
    background: rgba(15, 23, 42, 0.08);
    padding: 2px 8px;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 700;
}
.group-tab-btn.active .tab-count {
    background: rgba(255, 255, 255, 0.25);
    color: #ffffff;
}

/* =========================================
   アクティブフィルター表示バー
   ========================================= */
.active-filter-row {
    background: #eff6ff;
    border: 1px solid #bfdbfe;
    border-radius: var(--radius-md);
    padding: 10px 16px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

.filter-label {
    font-size: 0.85rem;
    font-weight: 700;
    color: #1e40af;
    display: flex;
    align-items: center;
    gap: 6px;
}

.filter-chips {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.filter-chip {
    background: #ffffff;
    border: 1px solid #93c5fd;
    color: #1e40af;
    font-size: 0.8rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: var(--radius-full);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.filter-chip button {
    background: transparent;
    border: none;
    color: #3b82f6;
    cursor: pointer;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    padding: 2px;
}
.filter-chip button:hover {
    color: var(--accent-red);
}

.reset-filter-btn {
    margin-left: auto;
    background: #ffffff;
    border: 1px solid #bfdbfe;
    color: #2563eb;
    font-size: 0.78rem;
    font-weight: 700;
    padding: 5px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}
.reset-filter-btn:hover {
    background: #dbeafe;
    color: #1d4ed8;
}

/* =========================================
   コンテンツレイアウト（2カラム）
   ========================================= */
.layout-grid {
    display: grid;
    grid-template-columns: 290px 1fr;
    gap: 28px;
    align-items: flex-start;
}

/* サイドバー */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: 20px;
    position: sticky;
    top: 76px;
}

.side-card {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 18px;
    box-shadow: var(--shadow-sm);
}

.side-card-title {
    font-size: 0.95rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
}

.trending-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.trending-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 0.86rem;
    line-height: 1.45;
    transition: var(--transition);
    cursor: pointer;
}
.trending-item:hover {
    background: var(--bg-subtle);
    color: var(--accent-blue);
}
.trending-rank {
    font-size: 0.85rem;
    font-weight: 900;
    color: var(--accent-red);
    flex-shrink: 0;
    min-width: 24px;
}
.trending-text {
    flex-grow: 1;
    font-weight: 600;
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.side-tag-btn {
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 6px 12px;
    min-height: 34px;
    border-radius: var(--radius-full);
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 4px;
}
.side-tag-btn:hover {
    border-color: var(--accent-blue);
    color: var(--accent-blue);
    background: #ffffff;
}
.side-tag-btn.active {
    background: var(--accent-blue-soft);
    border-color: var(--accent-blue);
    color: var(--accent-blue);
    font-weight: 800;
}

.side-tools-card {
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.side-tool-links {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.side-tool-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    border-radius: var(--radius-md);
    background: #ffffff;
    border: 1px solid var(--border-color);
    text-decoration: none;
    color: var(--text-primary);
    transition: var(--transition);
}
.side-tool-item:hover {
    border-color: var(--accent-blue);
    transform: translateX(3px);
    box-shadow: var(--shadow-xs);
}
.side-tool-item i {
    font-size: 1.1rem;
    color: var(--accent-blue);
    width: 20px;
    text-align: center;
}
.side-tool-item strong {
    display: block;
    font-size: 0.85rem;
    color: var(--text-primary);
}
.side-tool-item span {
    display: block;
    font-size: 0.72rem;
    color: var(--text-muted);
}

/* =========================================
   メインQAエリア
   ========================================= */
.main-qa-area {
    min-width: 0;
}

.qa-control-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    flex-wrap: wrap;
    gap: 10px;
    padding: 4px 2px;
}

.qa-count-label {
    font-size: 0.95rem;
    font-weight: 800;
    color: var(--text-primary);
    white-space: nowrap;
}
.qa-count-label span {
    color: var(--accent-blue);
    font-size: 1.1rem;
}

.qa-actions-right {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: nowrap;
}

.toggle-all-btn {
    background: #ffffff;
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    min-height: 38px;
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
    flex-shrink: 0;
}
.toggle-all-btn:hover {
    background: var(--bg-subtle);
    color: var(--text-primary);
}

.sort-select-wrap {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 600;
    white-space: nowrap;
}

.sort-select-wrap label {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.sort-select-wrap select {
    background: #ffffff;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 6px 10px;
    min-height: 38px;
    border-radius: var(--radius-sm);
    outline: none;
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}
.sort-select-wrap select:focus {
    border-color: var(--border-focus);
}

/* =========================================
   QA カード（アコーディオン）
   ========================================= */
.qa-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.qa-card {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: border-color 0.2s, box-shadow 0.2s;
    overflow: hidden;
}
.qa-card:hover {
    border-color: #cbd5e1;
    box-shadow: var(--shadow-md);
}
.qa-card[open] {
    border-color: #bfdbfe;
    box-shadow: var(--shadow-md);
}

.qa-summary {
    padding: 18px 22px;
    list-style: none;
    cursor: pointer;
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
    user-select: none;
    transition: background-color 0.15s ease;
}
.qa-summary::-webkit-details-marker {
    display: none;
}
.qa-summary:hover {
    background-color: #f8fafc;
}

.qa-q-left {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    flex-grow: 1;
}

.qa-q-badge {
    background: #e2e8f0;
    color: #334155;
    font-size: 0.8rem;
    font-weight: 800;
    padding: 4px 9px;
    border-radius: var(--radius-sm);
    flex-shrink: 0;
    margin-top: 2px;
    transition: var(--transition);
}
.qa-card[open] .qa-q-badge {
    background: var(--accent-blue);
    color: #ffffff;
}

.qa-q-text-wrap {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.qa-q-title {
    font-size: 1.05rem;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1.5;
}

.qa-tags-row {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.qa-tag-chip {
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.73rem;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: var(--radius-full);
}

.qa-chevron {
    color: var(--text-light);
    font-size: 1rem;
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
    margin-top: 6px;
    flex-shrink: 0;
}
.qa-card[open] .qa-chevron {
    transform: rotate(180deg);
    color: var(--accent-blue);
}

/* 回答コンテンツ */
.qa-answer-body {
    padding: 0 24px 24px 62px;
    color: var(--text-secondary);
    border-top: 1px solid #f1f5f9;
    background: #ffffff;
    animation: fadeIn 0.25s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-4px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 検索ハイライト */
mark.search-highlight {
    background: #fef08a;
    color: #713f12;
    padding: 0 2px;
    border-radius: 3px;
    font-weight: inherit;
}

/* リッチ装飾ボックス */
.ans-summary-box {
    background: #eff6ff;
    border-left: 4px solid var(--accent-blue);
    padding: 14px 18px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 16px 0;
    font-size: 0.95rem;
    color: #1e3a8a;
    font-weight: 700;
    line-height: 1.65;
}

.ans-detail-text {
    font-size: 0.95rem;
    line-height: 1.8;
    color: #1e293b;
    margin-bottom: 14px;
    white-space: pre-wrap;
}

.ans-action-box {
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
    border-left: 4px solid var(--accent-emerald);
    padding: 14px 18px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 14px 0;
    font-size: 0.92rem;
    color: #14532d;
    line-height: 1.7;
}

.ans-action-title {
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 6px;
    color: #15803d;
}

.ans-ng-box {
    background: #fff1f2;
    border: 1px solid #fecdd3;
    border-left: 4px solid var(--accent-red);
    padding: 14px 18px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 14px 0;
    font-size: 0.92rem;
    color: #881337;
    line-height: 1.7;
}

.ans-ng-title {
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 6px;
    color: #be123c;
}

/* 関連質問（Related Questions）チップ */
.ans-related-section {
    margin-top: 16px;
    padding-top: 12px;
    border-top: 1px solid #f1f5f9;
}
.ans-related-title {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-muted);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 6px;
}
.ans-related-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.related-chip {
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    min-height: 36px;
    border-radius: var(--radius-md);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: var(--transition);
    cursor: pointer;
}
.related-chip:hover {
    background: var(--accent-blue-soft);
    border-color: #93c5fd;
    color: var(--accent-blue);
    transform: translateY(-1px);
}
.related-chip .chip-qid {
    font-weight: 800;
    color: var(--accent-blue);
}

/* ラベルバッジ */
.ans-label-row {
    margin-top: 14px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.ans-badge {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 4px 10px;
    border-radius: var(--radius-full);
    font-size: 0.78rem;
    font-weight: 700;
}
.ans-badge.latest { background: #dcfce7; color: #166534; }
.ans-badge.warning { background: #fef3c7; color: #92400e; }
.ans-badge.alert { background: #ffe4e6; color: #9f1239; }
.ans-badge.info { background: #e0f2fe; color: #0369a1; }
.ans-badge.unconfirmed { background: #f3e8ff; color: #6b21a8; }

/* 内部ツール誘導リンクボタン */
.inline-tool-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    min-height: 44px;
    background: #f8fafc;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--accent-blue) !important;
    text-decoration: none;
    font-weight: 700;
    font-size: 0.88rem;
    transition: var(--transition);
    box-shadow: var(--shadow-xs);
    margin-top: 12px;
}
.inline-tool-link:hover {
    background: var(--accent-blue-soft);
    border-color: var(--accent-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}
.inline-tool-link i {
    font-size: 1rem;
    color: var(--accent-blue);
}

/* メタフッター */
.qa-footer-bar {
    margin-top: 18px;
    padding-top: 14px;
    border-top: 1px dashed var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.qa-meta-info {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 600;
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

.qa-footer-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.feedback-btn {
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 8px 14px;
    min-height: 40px;
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.feedback-btn:hover {
    background: #ffffff;
    border-color: #94a3b8;
    color: var(--text-primary);
}
.feedback-btn.voted-up {
    background: var(--accent-emerald-soft);
    border-color: var(--accent-emerald);
    color: var(--accent-emerald);
}
.feedback-btn.voted-down {
    background: var(--accent-red-soft);
    border-color: var(--accent-red);
    color: var(--accent-red);
}

.share-link-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--accent-blue);
    font-size: 0.8rem;
    font-weight: 700;
    cursor: pointer;
    padding: 8px 14px;
    min-height: 40px;
    border-radius: var(--radius-sm);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: var(--transition);
}
.share-link-btn:hover {
    background: var(--accent-blue-soft);
    border-color: #93c5fd;
}

/* =========================================
   トップへ戻るフローティングボタン
   ========================================= */
.back-to-top-btn {
    position: fixed;
    right: 24px;
    bottom: 30px;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-full);
    background: var(--accent-blue);
    color: #ffffff;
    border: none;
    box-shadow: var(--shadow-lg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    z-index: 990;
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: opacity 0.25s, transform 0.25s, visibility 0.25s;
}
.back-to-top-btn.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-to-top-btn:hover {
    background: var(--accent-blue-hover);
    transform: translateY(-2px);
}

/* =========================================
   トースト通知
   ========================================= */
.toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: #0f172a;
    color: #ffffff;
    padding: 12px 22px;
    border-radius: var(--radius-full);
    font-size: 0.88rem;
    font-weight: 600;
    box-shadow: var(--shadow-lg);
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
    pointer-events: none;
    white-space: nowrap;
}
.toast.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* =========================================
   フッター
   ========================================= */
.site-footer {
    background: #ffffff;
    border-top: 1px solid var(--border-color);
    padding: 40px 20px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: auto;
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.footer-nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 700;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    transition: color 0.15s;
}
.footer-nav a:hover {
    color: var(--accent-blue);
}

.footer-copy {
    color: var(--text-light);
    font-size: 0.8rem;
}

/* =========================================
   レスポンシブ対応（スマホ・テスラ車載）
   ========================================= */
@media (max-width: 900px) {
    .layout-grid {
        grid-template-columns: 1fr;
    }
    .sidebar {
        position: static;
        order: 2;
    }
    .main-qa-area {
        order: 1;
    }
    .tab-scroll-btn {
        display: none;
    }
}

@media (max-width: 640px) {
    .hero-title {
        font-size: 1.45rem;
        flex-direction: column;
        gap: 6px;
    }
    .hero-desc {
        font-size: 0.88rem;
    }
    .nav-inner {
        flex-direction: column;
        gap: 10px;
        align-items: stretch;
        padding: 8px 14px;
    }
    .nav-brand {
        justify-content: center;
    }
    .nav-tools {
        display: flex;
        flex-wrap: nowrap;
        overflow-x: auto;
        padding-bottom: 4px;
        justify-content: flex-start;
        -webkit-overflow-scrolling: touch;
    }
    .tool-chip {
        flex-shrink: 0;
        font-size: 0.78rem;
        padding: 6px 12px;
        min-height: 36px;
    }
    .search-card {
        padding: 16px;
        border-radius: var(--radius-lg);
    }
    .search-input-wrap input {
        font-size: 0.95rem;
        padding: 12px 42px 12px 40px;
    }
    .qa-control-bar {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
        margin-bottom: 12px;
    }
    .qa-actions-right {
        justify-content: space-between;
        width: 100%;
    }
    .toggle-all-btn {
        flex: 0 0 auto;
    }
    .sort-select-wrap {
        flex: 0 0 auto;
    }
    .qa-summary {
        padding: 16px 14px;
    }
    .qa-answer-body {
        padding: 0 14px 18px 14px;
    }
    .qa-q-left {
        gap: 10px;
    }
    .qa-q-title {
        font-size: 0.98rem;
    }
    .main-container {
        padding: 10px 12px 60px;
    }
    .back-to-top-btn {
        right: 16px;
        bottom: 20px;
        width: 44px;
        height: 44px;
    }
}