:root {
            --bg-color: #ffffff;
            --text-color: #1a1a1a;
            --accent-color: #6366f1;
            --nav-bg: rgba(255, 255, 255, 0.8);
            --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        }

        [data-theme="dark"] {
            --bg-color: #080808;
            --text-color: #f8fafc;
            --nav-bg: rgba(17, 17, 17, 0.8);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', sans-serif;
        }

        body {
            background-color: var(--bg-color);
            color: var(--text-color);
            transition: var(--transition);
            overflow-x: hidden;
        }

        /* --- Navbar --- */
        nav {
            position: fixed;
            top: 0;
            width: 100%;
            padding: 1.5rem 10%;
            display: flex;
            justify-content: space-between;
            align-items: center;
            background: var(--nav-bg);
            backdrop-filter: blur(10px);
            z-index: 1000;
        }

        .logo {
            font-size: 1.5rem;
            font-weight: 800;
            color: var(--accent-color);
        }

        /* --- Toggle Button with Icons --- */
        .theme-switch {
            position: relative;
            display: inline-block;
            width: 60px;
            height: 30px;
        }

        .theme-switch input {
            opacity: 0;
            width: 0;
            height: 0;
        }

        .slider {
            position: absolute;
            cursor: pointer;
            top: 0; left: 0; right: 0; bottom: 0;
            background-color: #334155;
            transition: .4s;
            border-radius: 30px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 6px;
        }

        /* Icons inside slider */
        .slider i {
            font-size: 14px;
            z-index: 1;
        }
        .fa-sun { color: #facc15; }
        .fa-moon { color: #f8fafc; }

        .slider:before {
            position: absolute;
            content: "";
            height: 22px;
            width: 22px;
            left: 4px;
            bottom: 4px;
            background-color: white;
            transition: .4s;
            border-radius: 50%;
            z-index: 2;
        }

        input:checked + .slider {
            background-color: var(--accent-color);
        }

        input:checked + .slider:before {
            transform: translateX(30px);
        }

        /* --- Hero Section --- */
        .hero {
            height: 100vh;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            text-align: center;
            padding: 0 20px;
        }

        .hero h1 {
            font-size: 4rem;
            margin-bottom: 1rem;
        }

        .hero p {
            font-size: 1.2rem;
            max-width: 600px;
            opacity: 0.8;
            margin-bottom: 2rem;
        }

        .btn {
            padding: 12px 30px;
            background-color: var(--accent-color);
            color: white;
            text-decoration: none;
            border-radius: 8px;
            font-weight: 600;
            transition: 0.3s;
        }

        @media (max-width: 768px) {
            .hero h1 { font-size: 2.5rem; }
            nav { padding: 1rem 5%; }
        }