/* --- Article Styles --- */
        /* --- GLOBAL VARIABLES --- */
        :root { 
            --primary: #0f172a; 
            --secondary: #334155; 
            --accent: #3b82f6; 
            --accent-hover: #1d4ed8; 
            --bg: #f8fafc; 
            --surface: #ffffff; 
            --border: #e2e8f0; 
            --text: #334155; 
            --text-light: #64748b; 
        }

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

        body { 
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; 
            background-color: var(--bg); 
            color: var(--text); 
            overflow-x: hidden;
            line-height: 1.6;
        }

        a { text-decoration: none; }

        /* --- NAVIGATION --- */
        nav {
            position: fixed;
            top: 0; left: 0; width: 100%;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid var(--border);
            z-index: 1000;
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 5%;
            transition: all 0.3s ease;
        }

        .brand { font-size: 1.5rem; font-weight: 800; color: var(--primary); display: flex; align-items: center; gap: 0.5rem; }
        nav .brand { position: relative; z-index: 1001; }
        .brand img { width: 32px; height: 32px; display: block; }

        .nav-links { display: flex; gap: 2rem; align-items: center; }
        .nav-links a { color: var(--secondary); font-weight: 600; transition: color 0.2s; }
        .nav-links a:hover { color: var(--accent); }
        .nav-links a.active { color: var(--accent); }
        
        .btn-nav {
            background: var(--accent); color: white !important;
            padding: 0.5rem 1.25rem; border-radius: 0.5rem;
            transition: background 0.2s, transform 0.2s;
        }
        .btn-nav:hover { background: var(--accent-hover); transform: translateY(-2px); }

        /* --- MOBILE MENU UTILITIES --- */
        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            background: none;
            border: none;
            cursor: pointer;
            z-index: 1001;
            padding: 5px;
        }
        .hamburger span {
            width: 25px; height: 3px; background-color: var(--primary); border-radius: 3px; transition: all 0.3s ease;
        }
        .nav-overlay {
            position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(15, 23, 42, 0.4);
            backdrop-filter: blur(2px); z-index: 999; opacity: 0; visibility: hidden; transition: all 0.3s ease;
        }
        .nav-overlay.show { opacity: 1; visibility: visible; }

        /* --- ARTICLE STYLES --- */
        .article-header {
            text-align: center;
            padding: 140px 5% 60px; 
            background: radial-gradient(circle at top, #e0f2fe 0%, var(--bg) 100%);
            border-bottom: 1px solid var(--border);
        }
        .article-tag {
            display: inline-block; background: var(--accent); color: white;
            padding: 4px 12px; border-radius: 20px; font-size: 0.85rem; font-weight: 700;
            margin-bottom: 1rem; letter-spacing: 0.5px;
        }
        .article-title {
            font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--primary);
            margin-bottom: 1rem; max-width: 900px; margin-left: auto; margin-right: auto; line-height: 1.2;
        }
        .article-meta { color: var(--text-light); font-size: 0.95rem; }
        
        .article-body {
            max-width: 800px; margin: 0 auto; padding: 60px 5%; font-size: 1.15rem; color: var(--secondary);
        }
        .article-body h2 { color: var(--primary); margin: 2.5rem 0 1rem; font-size: 1.8rem; }
        .article-body h3 { color: var(--primary); margin: 1.8rem 0 0.8rem; font-size: 1.4rem; }
        .article-body p { margin-bottom: 1.5rem; }
        .article-body ul { margin-bottom: 1.5rem; padding-left: 20px; }
        .article-body li { margin-bottom: 0.5rem; }
        .article-body strong { color: var(--primary); }
        .math-block {
            background: var(--surface); padding: 1.5rem; border-radius: 8px;
            border: 1px solid var(--border); margin: 1.5rem 0; text-align: center; overflow-x: auto;
        }
        .article-image-container { margin: 2rem 0; text-align: center; }
        .article-image-container img { max-width: 100%; border-radius: 8px; border: 1px solid var(--border); box-shadow: 0 10px 15px -3px rgba(0,0,0,0.05); }

        /* --- FOOTER & COOKIES --- */
        footer { background: var(--surface); border-top: 1px solid var(--border); padding: 3rem 5%; text-align: center; color: var(--text-light); }
        .footer-links { margin-top: 1rem; display: flex; justify-content: center; gap: 1.5rem; flex-wrap: wrap; }
        .footer-links a { color: var(--secondary); font-size: 0.9rem; }
        .footer-links a:hover { color: var(--accent); }

        /* (Include your existing cookie banner CSS here for production) */

        /* --- RESPONSIVE ADJUSTMENTS --- */
        @media (max-width: 768px) {
            .hamburger { display: flex; }
            .nav-links { 
                position: fixed; top: 0; right: -100%; width: 260px; height: 100vh;
                background-color: var(--surface); flex-direction: column; align-items: flex-start;
                padding: 80px 20px 20px 20px; box-shadow: -5px 0 25px rgba(0,0,0,0.1);
                transition: right 0.3s ease; z-index: 1000;
            }
            .nav-links.open { right: 0; }
            .nav-links a { width: 100%; padding: 12px 0; border-bottom: 1px solid var(--border); font-size: 1.1rem; }
            .nav-links .btn-nav { margin-top: 20px; text-align: center; border-bottom: none; }
            .hamburger.open span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
            .hamburger.open span:nth-child(2) { opacity: 0; }
            .hamburger.open span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
        }