/* _tools/root/extract_inline_css.py が書き出した。直すときは、これを直接直してよい */
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body {
            font-family: "Hiragino Mincho ProN", "BIZ UDPMincho", "Yu Mincho", YuMincho, "Noto Serif CJK JP", "Noto Serif JP", serif;
            background: linear-gradient(135deg, #0f0c29 0%, #302b63 50%, #24243e 100%);
            min-height: 100vh;
            color: #e0e0e0;
            padding: 2rem 1rem;
            line-height: 1.9;
        }
        body::before {
            content: '';
            position: fixed;
            top: 0; left: 0; width: 100%; height: 100%;
            background: radial-gradient(circle at 20% 50%, rgba(120, 119, 198, 0.15) 0%, transparent 50%),
                        radial-gradient(circle at 80% 80%, rgba(255, 107, 107, 0.1) 0%, transparent 50%);
            pointer-events: none;
            z-index: 0;
        }
        .container {
            max-width: 1000px;
            margin: 0 auto;
            position: relative;
            z-index: 1;
            background: rgba(255, 255, 255, 0.05);
            padding: 3rem;
            border-radius: 24px;
            border: 1px solid rgba(255, 255, 255, 0.1);
            box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
        }
        h1 {
            font-size: clamp(1.6rem, 4vw, 2.4rem);
            font-weight: 900;
            text-align: center;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 2.5rem;
            letter-spacing: 0.05em;
        }
        .toc {
            background: rgba(0, 0, 0, 0.3);
            padding: 2rem;
            border-radius: 16px;
            margin-bottom: 3rem;
            border: 1px solid rgba(255, 255, 255, 0.05);
        }
        .toc-title {
            font-weight: 700;
            font-size: 1.2rem;
            margin-bottom: 1.5rem;
            color: #fff;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        .toc-title::before { content: '◆'; color: #667eea; font-size: 0.8em; }
        .toc ul { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 0.8rem; }
        .toc li { position: relative; padding-left: 1.5rem; }
        .toc li::before { content: '▸'; position: absolute; left: 0; color: #667eea; }
        .toc a { color: #b8c1ec; text-decoration: none; transition: all 0.3s; }
        .toc a:hover { color: #fff; text-decoration: underline; }
        
        .subheading {
            font-weight: 700;
            font-size: 1.8rem;
            color: #fff;
            margin: 5rem 0 2rem 0;
            display: block;
            border-left: 6px solid #667eea;
            padding: 0.5rem 0 0.5rem 1.5rem;
            background: linear-gradient(90deg, rgba(102, 126, 234, 0.1) 0%, transparent 100%);
        }
        .subheading a { color: inherit; text-decoration: none; }
        
        /* Details style for Index */
        details {
            margin-bottom: 1.5rem;
            background: rgba(255, 255, 255, 0.03);
            border: 1px solid rgba(255, 255, 255, 0.08);
            border-radius: 16px;
            overflow: hidden;
            transition: all 0.3s ease;
        }
        details:hover {
            background: rgba(255, 255, 255, 0.06);
            border-color: rgba(102, 126, 234, 0.3);
        }
        summary {
            padding: 1.5rem 2rem;
            font-size: 1.4rem;
            font-weight: 700;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }
        summary::-webkit-details-marker { display: none; }
        .summary-title { flex-grow: 1; color: #fff; text-decoration: none; }
        .summary-title:hover { text-decoration: underline; }
        .summary-hint { font-size: 0.9rem; opacity: 0.5; font-weight: normal; }

        .details-content {
            padding: 0 2rem 2rem 3.5rem;
            border-top: 1px solid rgba(255, 255, 255, 0.05);
            margin-top: 0.5rem;
            padding-top: 1.5rem;
        }
        .details-content ul { list-style: none; }
        .details-content li { margin-bottom: 0.8rem; position: relative; }
        .details-content li::before { content: '▸'; position: absolute; left: -1.5rem; color: #667eea; }
        .details-content a { color: #a5b4fc; text-decoration: none; transition: 0.3s; font-size: 1.1rem; }
        .details-content a:hover { color: #fff; }

        .nav-links { margin-top: 5rem; text-align: center; }
        .nav-links a { display: inline-block; margin: 0.5rem; 
            color: #fff; text-decoration: none; padding: 1rem 2.5rem;
            background: rgba(255, 255, 255, 0.1); border-radius: 50px;
            transition: 0.3s; border: 1px solid rgba(255, 255, 255, 0.2);
            font-weight: 600;
        }
        .nav-links a:hover { background: rgba(255, 255, 255, 0.2); transform: translateY(-3px); }
        
        @media (max-width: 768px) {
            .container { padding: 1.5rem; }
            h1 { font-size: 2.2rem; }
            .subheading { font-size: 1.5rem; }
            .toc ul { grid-template-columns: 1fr; }
            summary { font-size: 1.2rem; padding: 1.2rem; }
        }