:root {
            --primary: #4a6fa5; 
            --secondary: #e63946; 
            --accent: #2a9d8f; 
            --light: #f8f9fa;
            --dark: #343a40;
            --gray: #6c757d;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
            --transition: all 0.3s ease;
            --border-radius: 8px;
            --max-width: 1200px;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: var(--dark);
            background-color: #fff;
            overflow-x: hidden;
        }
        a {
            color: var(--primary);
            text-decoration: none;
            transition: var(--transition);
        }
        a:hover {
            color: var(--secondary);
        }
        .container {
            width: 100%;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 20px;
        }
        .site-header {
            background-color: var(--light);
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        .header-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 20px;
        }
        .my-logo {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--primary);
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .my-logo:hover {
            color: var(--secondary);
        }
        .my-logo i {
            color: var(--accent);
        }
        .main-nav ul {
            display: flex;
            list-style: none;
            gap: 25px;
        }
        .main-nav a {
            font-weight: 600;
            padding: 8px 5px;
            position: relative;
        }
        .main-nav a:after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            background: var(--secondary);
            left: 0;
            bottom: 0;
            transition: var(--transition);
        }
        .main-nav a:hover:after {
            width: 100%;
        }
        .hamburger {
            display: none;
            flex-direction: column;
            cursor: pointer;
            gap: 5px;
        }
        .hamburger span {
            width: 25px;
            height: 3px;
            background-color: var(--dark);
            border-radius: 2px;
            transition: var(--transition);
        }
        .hamburger.active span:nth-child(1) {
            transform: rotate(45deg) translate(6px, 6px);
        }
        .hamburger.active span:nth-child(2) {
            opacity: 0;
        }
        .hamburger.active span:nth-child(3) {
            transform: rotate(-45deg) translate(6px, -6px);
        }
        .breadcrumb {
            padding: 15px 20px;
            background-color: #f1f3f5;
            font-size: 0.9rem;
            margin-bottom: 20px;
        }
        .breadcrumb a {
            color: var(--gray);
        }
        .breadcrumb a:hover {
            color: var(--primary);
        }
        .breadcrumb span {
            margin: 0 8px;
            color: var(--gray);
        }
        .hero {
            text-align: center;
            padding: 40px 20px;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            border-radius: var(--border-radius);
            margin: 20px auto 40px;
        }
        .hero h1 {
            font-size: 2.8rem;
            margin-bottom: 15px;
            color: var(--primary);
        }
        .hero p {
            font-size: 1.2rem;
            color: var(--dark);
            max-width: 800px;
            margin: 0 auto;
        }
        .content-wrapper {
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 40px;
            margin: 40px auto;
        }
        .main-content {
            background: #fff;
            padding: 30px;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
        }
        .sidebar {
            background: var(--light);
            padding: 25px;
            border-radius: var(--border-radius);
            align-self: start;
            position: sticky;
            top: 120px;
        }
        h1, h2, h3, h4 {
            margin-top: 1.5em;
            margin-bottom: 0.7em;
            color: var(--primary);
            line-height: 1.3;
        }
        h1 {
            font-size: 2.8rem;
            border-bottom: 3px solid var(--accent);
            padding-bottom: 10px;
        }
        h2 {
            font-size: 2rem;
            border-left: 5px solid var(--secondary);
            padding-left: 15px;
        }
        h3 {
            font-size: 1.6rem;
            color: var(--accent);
        }
        h4 {
            font-size: 1.3rem;
            color: var(--dark);
        }
        p {
            margin-bottom: 1.5em;
            text-align: justify;
        }
        b, strong {
            color: var(--secondary);
            font-weight: 700;
        }
        .highlight {
            background-color: #fff3cd;
            padding: 20px;
            border-left: 4px solid #ffc107;
            margin: 25px 0;
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
        }
        .emoji {
            font-size: 1.2em;
            margin-right: 5px;
        }
        .article-img {
            width: 100%;
            height: auto;
            border-radius: var(--border-radius);
            margin: 25px 0;
            box-shadow: var(--shadow);
            transition: var(--transition);
        }
        .article-img:hover {
            transform: scale(1.01);
        }
        .module {
            background: #fff;
            padding: 25px;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            margin-bottom: 30px;
        }
        .module h3 {
            margin-top: 0;
            color: var(--primary);
        }
        .form-group {
            margin-bottom: 20px;
        }
        .form-group label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
        }
        .form-control {
            width: 100%;
            padding: 12px 15px;
            border: 1px solid #ced4da;
            border-radius: var(--border-radius);
            font-size: 1rem;
            transition: var(--transition);
        }
        .form-control:focus {
            border-color: var(--primary);
            outline: none;
            box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.2);
        }
        .btn {
            display: inline-block;
            padding: 12px 30px;
            background-color: var(--primary);
            color: white;
            border: none;
            border-radius: var(--border-radius);
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
        }
        .btn:hover {
            background-color: var(--secondary);
            transform: translateY(-2px);
        }
        .stars {
            display: flex;
            gap: 10px;
            margin: 15px 0;
        }
        .star {
            font-size: 1.8rem;
            color: #ddd;
            cursor: pointer;
            transition: var(--transition);
        }
        .star:hover,
        .star.active {
            color: #ffc107;
        }
        .internal-links {
            background-color: #e9f7fe;
            padding: 20px;
            border-radius: var(--border-radius);
            margin: 30px 0;
        }
        .internal-links h4 {
            color: var(--primary);
            margin-top: 0;
        }
        .internal-links ul {
            list-style: none;
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 15px;
        }
        .internal-links li {
            padding: 5px 0;
        }
        .last-updated {
            text-align: right;
            font-style: italic;
            color: var(--gray);
            font-size: 0.9rem;
            padding-top: 20px;
            border-top: 1px dashed #dee2e6;
            margin-top: 40px;
        }
        .site-footer {
            background-color: var(--dark);
            color: var(--light);
            padding: 50px 20px 30px;
            margin-top: 60px;
        }
        .footer-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
            max-width: var(--max-width);
            margin: 0 auto;
        }
        .footer-section h4 {
            color: var(--light);
            margin-bottom: 20px;
            font-size: 1.2rem;
        }
        .footer-links {
            list-style: none;
        }
        .footer-links li {
            margin-bottom: 10px;
        }
        .footer-links a {
            color: #adb5bd;
        }
        .footer-links a:hover {
            color: white;
            padding-left: 5px;
        }
        friend-link {
            display: block;
            background: rgba(255,255,255,0.05);
            padding: 10px 15px;
            border-radius: 4px;
            margin: 8px 0;
        }
        .copyright {
            text-align: center;
            padding-top: 30px;
            margin-top: 30px;
            border-top: 1px solid #495057;
            color: #adb5bd;
            font-size: 0.9rem;
        }
        @media (max-width: 992px) {
            .content-wrapper {
                grid-template-columns: 1fr;
            }
            .sidebar {
                position: static;
            }
            h1 {
                font-size: 2.4rem;
            }
            h2 {
                font-size: 1.8rem;
            }
        }
        @media (max-width: 768px) {
            .hamburger {
                display: flex;
            }
            .main-nav ul {
                position: fixed;
                top: 80px;
                left: -100%;
                flex-direction: column;
                background: var(--light);
                width: 100%;
                padding: 30px;
                box-shadow: var(--shadow);
                transition: var(--transition);
                z-index: 999;
            }
            .main-nav.active ul {
                left: 0;
            }
            .main-nav a {
                display: block;
                padding: 15px;
                border-bottom: 1px solid #eee;
            }
            .main-nav a:after {
                display: none;
            }
            .hero h1 {
                font-size: 2rem;
            }
            .hero p {
                font-size: 1rem;
            }
        }