:root {
    /* Color Palette */
    --bg-dark: #050508;
    --bg-card: rgba(20, 20, 30, 0.4);
    --bg-card-hover: rgba(30, 30, 45, 0.6);
    
    --accent-1: #6366f1; /* Indigo */
    --accent-2: #ec4899; /* Pink */
    --accent-3: #8b5cf6; /* Violet */
    --accent-4: #14b8a6; /* Teal */
    
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    
    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
    
    --sidebar-width: 280px;
    
    /* Typography */
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 40px;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

/* --- Animated Background --- */
.bg-elements {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    overflow: hidden;
}

.blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.4;
    animation: float 20s infinite ease-in-out;
}

.blob-1 {
    top: -10%;
    left: -10%;
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, rgba(99,102,241,0.4) 0%, rgba(0,0,0,0) 70%);
}

.blob-2 {
    bottom: -20%;
    right: -10%;
    width: 50vw;
    height: 50vw;
    background: radial-gradient(circle, rgba(236,72,153,0.3) 0%, rgba(0,0,0,0) 70%);
    animation-delay: -5s;
}

.blob-3 {
    top: 40%;
    left: 40%;
    width: 40vw;
    height: 40vw;
    background: radial-gradient(circle, rgba(20,184,166,0.2) 0%, rgba(0,0,0,0) 70%);
    animation-delay: -10s;
}

.noise-overlay {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)' opacity='0.03'/%3E%3C/svg%3E");
    pointer-events: none;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(5%, 5%) scale(1.05); }
    50% { transform: translate(-5%, 10%) scale(0.95); }
    75% { transform: translate(-10%, -5%) scale(1.02); }
}

/* --- Layout --- */
.mobile-header {
    display: none;
}

.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background: rgba(10, 10, 15, 0.6);
    backdrop-filter: blur(20px);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 2rem 0;
    z-index: 100;
    transition: transform 0.3s ease;
}

.logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0 2rem;
    margin-bottom: 3rem;
}

.logo-icon {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.4);
}

.logo span {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    background: linear-gradient(to right, #fff, #a5b4fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    list-style: none;
    flex: 1;
    overflow-y: auto;
    padding: 0 1rem;
}

.nav-links::-webkit-scrollbar {
    width: 4px;
}
.nav-links::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

.nav-item {
    margin-bottom: 0.5rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: var(--text-muted);
    text-decoration: none;
    border-radius: 10px;
    transition: all 0.2s ease;
    font-size: 0.95rem;
    font-weight: 500;
}

.nav-link:hover, .nav-link.active {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-main);
}

.nav-link.active {
    background: linear-gradient(90deg, rgba(99,102,241,0.1) 0%, transparent 100%);
    border-left: 3px solid var(--accent-1);
}

.nav-link i {
    width: 18px;
    height: 18px;
    opacity: 0.7;
    transition: all 0.2s;
}

.nav-link:hover i, .nav-link.active i {
    opacity: 1;
    color: var(--accent-1);
}

.sidebar-footer {
    padding: 2rem 2rem 0;
    font-size: 0.8rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    margin-top: 1rem;
}

/* --- Main Content Area --- */
.main-content {
    margin-left: var(--sidebar-width);
    padding: 4rem 5%;
    max-width: 1400px;
}

.hero {
    margin-bottom: 5rem;
    text-align: left;
}

.hero-badge {
    display: inline-block;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    color: #a5b4fc;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.hero h1 {
    font-family: var(--font-heading);
    font-size: clamp(3rem, 5vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -1px;
}

.text-gradient {
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-size: 200% auto;
    animation: gradientShift 5s ease infinite;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: 2.5rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.8rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: white;
    border: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

/* --- Roadmap Sections --- */
.roadmap-section {
    margin-bottom: 6rem;
    scroll-margin-top: 100px;
}

.section-header {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    margin-bottom: 2.5rem;
}

.section-icon {
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-1);
    box-shadow: inset 0 0 20px rgba(99,102,241,0.1);
}

.section-header h2 {
    font-family: var(--font-heading);
    font-size: 2.2rem;
    font-weight: 700;
    color: #fff;
    letter-spacing: -0.5px;
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.glass-card {
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}

.glass-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent-1), transparent);
    transform: translateX(-100%);
    transition: transform 0.6s ease;
}

.glass-card:hover {
    transform: translateY(-5px);
    background: var(--bg-card-hover);
    border-color: var(--border-hover);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2),
                0 0 20px rgba(99, 102, 241, 0.1);
}

.glass-card:hover::before {
    transform: translateX(100%);
}

.glass-card h3 {
    font-family: var(--font-heading);
    font-size: 1.3rem;
    margin-bottom: 1.2rem;
    color: #e2e8f0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.glass-card ul {
    list-style: none;
}

.glass-card li {
    color: var(--text-muted);
    margin-bottom: 0.8rem;
    padding-left: 1.5rem;
    position: relative;
    font-size: 0.95rem;
    line-height: 1.5;
}

.glass-card li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.5rem;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent-1);
    opacity: 0.7;
    box-shadow: 0 0 8px var(--accent-1);
}

.math-equation {
    background: rgba(0,0,0,0.3);
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid rgba(255,255,255,0.05);
    margin: 1rem 0;
    text-align: center;
    overflow-x: auto;
}

/* --- Learning Path Horizontal --- */
.learning-path-section {
    margin-top: 8rem;
    margin-bottom: 4rem;
}

.path-container {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 3rem;
}

.path-step {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.step-box {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    padding: 0.8rem 1.2rem;
    border-radius: 10px;
    font-size: 0.9rem;
    font-weight: 500;
    color: #e2e8f0;
    transition: all 0.3s;
}

.step-box:hover {
    background: rgba(99, 102, 241, 0.15);
    border-color: rgba(99, 102, 241, 0.4);
    color: #fff;
    transform: scale(1.05);
}

.step-arrow {
    color: var(--accent-2);
    opacity: 0.7;
}

.path-summary {
    text-align: center;
    background: linear-gradient(to right, rgba(20,20,30,0.6), rgba(30,30,45,0.6));
    border-left: 4px solid var(--accent-2);
}

.path-summary h3 {
    margin-bottom: 1rem;
    color: var(--accent-2);
}

/* --- Footer --- */
footer {
    text-align: center;
    padding: 3rem 0;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

.icon-small {
    width: 14px;
    height: 14px;
    display: inline-block;
    vertical-align: middle;
    color: var(--accent-2);
}

/* --- Animations --- */
.slide-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.slide-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    :root {
        --sidebar-width: 240px;
    }
    .cards-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        width: 280px;
        background: rgba(10, 10, 15, 0.95);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0;
        padding: 6rem 1.5rem 3rem;
    }
    
    .mobile-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        padding: 1rem 1.5rem;
        background: rgba(10, 10, 15, 0.8);
        backdrop-filter: blur(12px);
        z-index: 99;
        border-bottom: 1px solid var(--border-color);
    }
    
    .menu-toggle {
        background: transparent;
        border: none;
        color: var(--text-main);
        cursor: pointer;
    }
    
    .desktop-only {
        display: none;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
    }
}