:root {
            --primary-color: #2563eb;
            --primary-dark: #1e40af;
            --secondary-color: #10b981;
            --secondary-dark: #0d9488;
            --background-dark: #0f172a;
            --background-darker: #020617;
            --background-light: #f8fafc;
            --text-dark: #e2e8f0;
            --text-light: #1e293b;
            --card-bg-dark: #1e293b;
            --card-bg-light: #ffffff;
            --border-radius: 12px;
            --box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
        }

        :root.light-mode {
            --primary-color: #10b981;
            --primary-dark: #059669;
            --secondary-color: #2563eb;
            --secondary-dark: #1d4ed8;
            --background-dark: #f8fafc;
            --background-light: #0f172a;
            --text-dark: #1e293b;
            --text-light: #e2e8f0;
            --card-bg-dark: #ffffff;
            --card-bg-light: #1e293b;
        }

        body {
            background: var(--background-dark);
            color: var(--text-dark);
            font-family: 'Montserrat', sans-serif;
            line-height: 1.7;
            transition: background 0.5s, color 0.5s;
        }

        /* Typography */
        h1, h2, h3, h4, h5, h6 {
            font-family: 'Poppins', sans-serif;
            font-weight: 600;
            line-height: 1.3;
        }

        h2 {
            font-size: 2.5rem;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 2rem;
            position: relative;
            display: inline-block;
        }

        h2::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 0;
            width: 60px;
            height: 4px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 2px;
        }

        h3 {
            font-size: 2rem;
            margin: 2.5rem 0 1.5rem;
            color: var(--text-dark);
        }

        h4 {
            font-size: 1.5rem;
            margin: 2rem 0 1rem;
        }

        p {
            font-size: 1.1rem;
            opacity: 0.9;
            margin-bottom: 1.5rem;
        }

        /* Custom Scrollbar */
        ::-webkit-scrollbar {
            width: 10px;
        }

        ::-webkit-scrollbar-track {
            background: var(--background-dark);
        }

        ::-webkit-scrollbar-thumb {
            background: var(--primary-color);
            border-radius: 5px;
        }

        /* Navbar */
        .navbar {
            background: rgba(15, 23, 42, 0.95);
            backdrop-filter: blur(10px);
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            padding: 1rem 0;
            transition: var(--transition);
        }

        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
            color: var(--text-dark);
            transition: color 0.3s;
            display: flex;
            align-items: center;
            gap: 10px;
        }

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

        .navbar-brand i {
            font-size: 1.3rem;
        }

        .light-mode .navbar {
            background: rgba(248, 250, 252, 0.95);
        }

        /* Cards */
        .card {
            background: var(--card-bg-dark);
            border-radius: var(--border-radius);
            border: none;
            overflow: hidden;
            transition: var(--transition);
            box-shadow: var(--box-shadow);
            height: 100%;
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.2);
        }

        .card-img-container {
            overflow: hidden;
            position: relative;
        }

        .card img {
            transition: var(--transition);
            width: 100%;
            height: auto;
        }

        .card:hover img {
            transform: scale(1.05);
        }

        .card-body {
            padding: 1.5rem;
        }

        .card-text {
            opacity: 0.8;
            font-size: 0.95rem;
            margin-top: 0.5rem;
            color: var(--text-dark);
        }

        /* Project Highlights */
        .project-highlight {
            background: rgba(37, 99, 235, 0.1);
            border-left: 4px solid var(--primary-color);
            padding: 2rem;
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
            margin: 3rem 0;
            transition: var(--transition);
        }

        .project-highlight h3, .project-highlight h4 {
            margin-top: 0;
        }

        .project-highlight ul {
            padding-left: 1.5rem;
        }

        .project-highlight li {
            margin-bottom: 0.5rem;
        }

        /* Buttons */
        .btn-primary {
            background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
            border: none;
            border-radius: var(--border-radius);
            padding: 0.75rem 1.5rem;
            font-weight: 600;
            transition: var(--transition);
            box-shadow: var(--box-shadow);
        }

        .btn-primary:hover {
            background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
            transform: translateY(-2px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.2);
        }

        /* Floating Buttons */
        .floating-btn {
            position: fixed;
            bottom: 20px;
            right: 20px;
            display: flex;
            flex-direction: column;
            gap: 15px;
            z-index: 1000;
        }

        .back-to-top,
        .theme-toggle {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            background: var(--primary-color);
            color: white;
            border: none;
            cursor: pointer;
            transition: var(--transition);
            box-shadow: var(--box-shadow);
        }

        .back-to-top:hover,
        .theme-toggle:hover {
            transform: translateY(-5px) scale(1.1);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
        }

        .back-to-top {
            bottom: 85px;
        }

        /* Back Button */
        .back-button {
            position: fixed;
            bottom: 40px;
            left: 20px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: white;
            border: none;
            border-radius: var(--border-radius);
            padding: 12px 24px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            box-shadow: var(--box-shadow);
            display: flex;
            align-items: center;
            gap: 8px;
            z-index: 1000;
        }

        .back-button:hover {
            background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
            transform: translateY(-2px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.2);
        }

        /* Footer */
        footer {
            background: var(--background-darker);
            color: var(--text-dark);
            padding: 2rem 0;
            margin-top: 4rem;
            text-align: center;
            transition: background 0.5s, color 0.5s;
        }

        footer p {
            margin: 0;
            font-size: 0.9rem;
            opacity: 0.8;
        }

        .light-mode footer {
            background: #e2e8f0;
            color: var(--text-dark);
        }

        /* Animations */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .animate-fadeIn {
            animation: fadeIn 0.6s ease-out forwards;
        }

        .delay-100 { animation-delay: 0.1s; }
        .delay-200 { animation-delay: 0.2s; }
        .delay-300 { animation-delay: 0.3s; }
        .delay-400 { animation-delay: 0.4s; }
        .delay-500 { animation-delay: 0.5s; }

        /* Responsive Adjustments */
        @media (max-width: 768px) {
            h2 {
                font-size: 2rem;
            }
            
            h3 {
                font-size: 1.75rem;
            }
            
            .project-highlight {
                padding: 1.5rem;
            }
            
            .back-button {
                bottom: 20px;
                left: 50%;
                transform: translateX(-50%);
                padding: 10px 20px;
            }
        }