:root {
            --primary: #1a73e8;
            --secondary: #fbbc04;
            --dark: #202124;
            --light: #f8f9fa;
            --gray: #5f6368;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
            --radius: 8px;
            --transition: all 0.3s ease;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
            line-height: 1.6;
            color: var(--dark);
            background-color: var(--light);
            overflow-x: hidden;
        }
        a {
            text-decoration: none;
            color: inherit;
        }
        ul { list-style: none; }
        img { max-width: 100%; height: auto; display: block; }
        .header {
            background: white;
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        .header-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 80px;
        }
        .logo {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--primary);
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .logo i { color: var(--secondary); }
        .nav-desktop ul {
            display: flex;
            gap: 30px;
        }
        .nav-desktop a {
            font-weight: 600;
            padding: 8px 12px;
            border-radius: var(--radius);
            transition: var(--transition);
        }
        .nav-desktop a:hover {
            background: var(--primary);
            color: white;
        }
        .hamburger {
            display: none;
            font-size: 1.5rem;
            cursor: pointer;
            color: var(--dark);
        }
        .nav-mobile {
            display: none;
            background: white;
            padding: 20px;
            box-shadow: var(--shadow);
            flex-direction: column;
            gap: 15px;
            position: absolute;
            top: 80px;
            left: 0;
            right: 0;
            z-index: 999;
        }
        .nav-mobile.active { display: flex; }
        .nav-mobile a {
            padding: 12px;
            border-bottom: 1px solid #eee;
            font-weight: 600;
        }
        .nav-mobile a:hover { color: var(--primary); }
        .breadcrumb {
            max-width: 1200px;
            margin: 20px auto;
            padding: 0 20px;
            font-size: 0.9rem;
            color: var(--gray);
        }
        .breadcrumb a:hover { text-decoration: underline; }
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 40px;
        }
        .main-content { background: white; padding: 30px; border-radius: var(--radius); box-shadow: var(--shadow); }
        .sidebar { background: white; padding: 25px; border-radius: var(--radius); box-shadow: var(--shadow); height: fit-content; }
        h1 { font-size: 2.5rem; color: var(--dark); margin-bottom: 20px; line-height: 1.2; }
        h2 { font-size: 1.8rem; color: var(--primary); margin: 30px 0 15px; padding-bottom: 10px; border-bottom: 2px solid var(--secondary); }
        h3 { font-size: 1.4rem; color: var(--dark); margin: 20px 0 10px; }
        h4 { font-size: 1.1rem; color: var(--gray); margin: 15px 0 8px; }
        p { margin-bottom: 18px; color: #333; }
        .lead { font-size: 1.2rem; font-weight: 500; color: var(--gray); margin-bottom: 30px; }
        .highlight { background: #e8f0fe; padding: 20px; border-left: 4px solid var(--primary); margin: 25px 0; border-radius: 0 var(--radius) var(--radius) 0; }
        .emoji { font-size: 1.2em; margin-right: 5px; }
        .content-link {
            color: var(--primary);
            font-weight: 600;
            border-bottom: 1px dashed var(--primary);
            transition: var(--transition);
        }
        .content-link:hover {
            border-bottom: 2px solid var(--secondary);
            color: #d93025;
        }
        .feature-img {
            width: 100%;
            border-radius: var(--radius);
            margin: 30px 0;
            box-shadow: var(--shadow);
        }
        .interactive-module {
            background: #f8f9fa;
            padding: 25px;
            border-radius: var(--radius);
            margin: 40px 0;
            border: 1px solid #ddd;
        }
        .module-title { font-size: 1.3rem; margin-bottom: 20px; color: var(--dark); }
        form { display: flex; flex-direction: column; gap: 15px; }
        input, textarea, select {
            padding: 12px 15px;
            border: 1px solid #ccc;
            border-radius: var(--radius);
            font-family: inherit;
            font-size: 1rem;
            transition: var(--transition);
        }
        input:focus, textarea:focus, select:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.2);
        }
        button, .btn {
            background: var(--primary);
            color: white;
            border: none;
            padding: 12px 20px;
            border-radius: var(--radius);
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }
        button:hover, .btn:hover { background: #0d62d9; transform: translateY(-2px); }
        .sidebar-widget { margin-bottom: 30px; }
        .sidebar-title { font-size: 1.2rem; margin-bottom: 15px; color: var(--dark); padding-bottom: 8px; border-bottom: 1px solid #eee; }
        .related-links li { margin-bottom: 10px; }
        .related-links a { display: block; padding: 10px 15px; background: #f1f3f4; border-radius: var(--radius); transition: var(--transition); }
        .related-links a:hover { background: var(--primary); color: white; }
        footer {
            background: var(--dark);
            color: white;
            margin-top: 60px;
            padding: 40px 20px;
        }
        .footer-container {
            max-width: 1200px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
        }
        .footer-logo { font-size: 1.8rem; font-weight: 800; color: white; margin-bottom: 20px; }
        .friend-links { display: flex; flex-wrap: wrap; gap: 15px; margin: 20px 0; }
        .friend-link {
            display: inline-block;
            padding: 8px 16px;
            background: rgba(255, 255, 255, 0.1);
            border-radius: var(--radius);
            transition: var(--transition);
        }
        .friend-link:hover { background: var(--primary); }
        .copyright { margin-top: 40px; padding-top: 20px; border-top: 1px solid #444; text-align: center; color: #aaa; font-size: 0.9rem; }
        @media (max-width: 992px) {
            .container { grid-template-columns: 1fr; }
            .sidebar { order: -1; }
        }
        @media (max-width: 768px) {
            .header-container { height: 70px; }
            .nav-desktop { display: none; }
            .hamburger { display: block; }
            h1 { font-size: 2rem; }
            h2 { font-size: 1.6rem; }
        }