:root {
            --accent-green: #76ff03;
            --accent-green-dark: #64dd17;
            --text-primary: #212121;
            --text-secondary: #5f5f5f;
            --background-main: #f8f9fa;
            --background-glass: rgba(255, 255, 255, 0.6);
            --border-light: rgba(0, 0, 0, 0.1);
        }

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

        body {
            font-family: 'Exo 2', sans-serif;
            background-color: var(--background-main);
            background-image: url('https://images.stockcake.com/public/b/8/8/b88a3053-3d9d-444f-a235-b1125792d587/futuristic-skyline-view-stockcake.jpg');
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
            color: var(--text-primary);
            line-height: 1.7;
        }

        .navbar {
            background: var(--background-glass);
            padding: 15px 0;
            border-bottom: 1px solid var(--border-light);
            position: sticky;
            top: 0;
            z-index: 1000;
            backdrop-filter: blur(12px);
        }

        .navbar ul {
            list-style: none;
            display: flex;
            justify-content: center;
            gap: 30px;
        }

        .navbar a {
            color: var(--text-secondary);
            text-decoration: none;
            font-size: 16px;
            font-weight: 500;
            padding: 8px 15px;
            border-radius: 6px;
            transition: all 0.2s ease-in-out;
        }

        .navbar a:hover {
            color: var(--text-primary);
        }

        .navbar a.active {
            color: var(--accent-green);
            font-weight: 600;
        }

        .main-container {
            display: flex;
            max-width: 1300px;
            margin: 40px auto;
            padding: 0 20px;
            gap: 30px;
        }

        .sidebar-menu {
            flex: 0 0 260px;
            background: var(--background-glass);
            backdrop-filter: blur(12px);
            border-radius: 12px;
            padding: 25px;
            border: 1px solid var(--border-light);
            align-self: flex-start;
        }

        .sidebar-menu h2 {
            font-size: 20px;
            font-weight: 600;
            margin-bottom: 20px;
            padding-bottom: 15px;
            border-bottom: 1px solid var(--border-light);
            text-align: center;
        }

        .sidebar-menu ul {
            list-style: none;
        }

        .sidebar-menu > ul > li {
            margin-bottom: 5px;
        }
        
        .sidebar-menu a {
            color: var(--text-secondary);
            text-decoration: none;
            display: block;
            padding: 10px 15px;
            border-radius: 6px;
            font-weight: 400;
            font-size: 15px;
            transition: all 0.2s ease-in-out;
        }

        .sidebar-menu > ul > li > a:hover,
        .sidebar-menu > ul > li.active-section > a {
            background-color: rgba(0, 0, 0, 0.05);
            color: var(--text-primary);
            font-weight: 500;
        }

        .submenu {
            list-style: none;
            padding-left: 20px;
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out;
        }

        .sidebar-menu > ul > li:hover .submenu,
        .sidebar-menu > ul > li.active-section .submenu {
             max-height: 500px;
        }

        .submenu a {
            font-size: 14px;
            padding: 6px 15px;
            position: relative;
        }
        
        .submenu a:hover {
            color: var(--accent-green);
        }

        .content-area {
            flex: 1;
        }

        .welcome-box {
            background: var(--background-glass);
            backdrop-filter: blur(12px);
            border-radius: 12px;
            padding: 40px;
            border: 1px solid var(--border-light);
        }

        .welcome-box h1 {
            font-size: 34px;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 8px;
        }

        .welcome-box .tagline {
            font-size: 18px;
            color: var(--text-secondary);
            margin-bottom: 30px;
            font-weight: 300;
        }

        .welcome-box p {
            margin-bottom: 20px;
            font-size: 16px;
            color: var(--text-secondary);
            font-weight: 400;
        }
        
        .section-description {
            margin-left: 20px;
            padding-left: 15px;
            border-left: 2px solid var(--accent-green);
        }

.sidebar-menu > ul > li.active-section > a {
    background-color: rgba(0, 0, 0, 0.05);
    color: var(--text-primary);
    font-weight: 500;
}