:root {
    --primary: #00f2fe;
    --secondary: #7000ff;
    --dark: #000000;
    --glass: rgba(255, 255, 255, 0.03);
    --border: rgba(255, 255, 255, 0.1);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Inter', sans-serif; scroll-behavior: smooth; }

body { background-color: var(--dark); color: white; overflow-x: hidden; }

/* 1. GLASS NAVIGATION */
.glass-nav {
    position: fixed; top: 0; width: 100%; padding: 20px 8%;
    display: flex; justify-content: space-between; align-items: center;
    backdrop-filter: blur(20px); background: var(--glass);
    border-bottom: 1px solid var(--border); z-index: 1000;
}

.logo { font-size: 1.8rem; font-weight: 900; letter-spacing: 2px; }
.logo span { color: var(--primary); }

.nav-links { display: flex; list-style: none; gap: 30px; }
.nav-links a { text-decoration: none; color: white; font-weight: 500; transition: 0.3s; }
.nav-links a:hover { color: var(--primary); }

/* Submenu Magic */
.dropdown { position: relative; }
.submenu {
    position: absolute; top: 100%; left: 0; background: #111;
    width: 200px; display: none; padding: 15px; border-radius: 10px;
}
.dropdown:hover .submenu { display: block; animation: fadeIn 0.3s forwards; }
.submenu li { list-style: none; margin-bottom: 10px; }

/* 2. HERO SECTION */
.hero-portal {
    height: 100vh; display: flex; align-items: center; justify-content: center;
    text-align: center; position: relative; overflow: hidden;
}

.hero-content h1 {
    font-size: 6vw; line-height: 0.9; margin-bottom: 20px;
    background: linear-gradient(to bottom, #fff, var(--primary));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}

.cta-group { display: flex; gap: 20px; justify-content: center; margin-top: 40px; }
.cta-main {
    padding: 15px 40px; background: var(--primary); color: #000;
    text-decoration: none; font-weight: 800; border-radius: 50px;
    box-shadow: 0 0 20px rgba(0, 242, 254, 0.4); transition: 0.3s;
}

.cta-ghost {
    padding: 15px 40px; border: 1px solid var(--primary); color: var(--primary);
    text-decoration: none; font-weight: 800; border-radius: 50px;
}

/* 3. CATEGORY GRID (Neural Cluster) */
.category-section { padding: 100px 8%; }
.category-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px; margin-top: 50px;
}

.cat-card {
    background: var(--glass); border: 1px solid var(--border);
    padding: 30px; border-radius: 20px; text-align: center;
    transition: 0.4s; cursor: pointer;
}

.cat-card:hover {
    border-color: var(--primary); transform: translateY(-10px);
    background: rgba(0, 242, 254, 0.05);
}

/* 4. LESSONS LIST */
.lessons-section { padding: 50px 8% 100px; }
.lessons-list {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px; margin-top: 40px;
}

.lesson-card {
    background: var(--glass); padding: 30px; border-radius: 15px;
    border-left: 5px solid var(--primary); position: relative;
}

.lesson-card a {
    display: inline-block; margin-top: 20px; color: var(--primary);
    text-decoration: none; font-weight: bold;
}

@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }