:root {
    /* Colors */
    --bg-dark: #0a0a0f;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-card-hover: rgba(255, 255, 255, 0.1);
    --text-main: #ffffff;
    --text-muted: #a0a0b0;
    
    --primary: #00f2ff; /* Cyan Neon */
    --secondary: #7000ff; /* Purple Neon */
    --accent: #ff0055; /* Pink Neon */
    
    /* Status Colors */
    --success-color: #00ff88; /* Green Neon */
    --warning-color: #ffa500; /* Orange */
    --disabled-color: #555555; /* Gray */

    /* Gradients */
    --gradient-text: linear-gradient(135deg, var(--primary), var(--secondary));
    --gradient-blob: linear-gradient(45deg, var(--secondary), var(--accent));

    /* Spacing */
    --container-width: 1200px;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;

    /* Borders */
    --radius-md: 12px;
    --radius-lg: 24px;
    --border-light: 1px solid rgba(255, 255, 255, 0.1);
}

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

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

h1, h2, h3, .logo {
    font-family: 'Outfit', sans-serif;
}

a {
    text-decoration: none;
    color: inherit;
    transition: 0.3s ease;
}

ul {
    list-style: none;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
.site-header {
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: var(--border-light);
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 900;
    letter-spacing: -0.02em;
}

.highlight {
    color: var(--primary);
}

.main-nav ul {
    display: flex;
    gap: var(--spacing-md);
}

.main-nav a:hover {
    color: var(--primary);
}

/* Buttons */
.btn-primary {
    background: var(--primary);
    color: var(--bg-dark);
    padding: 0.8rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 700;
    border: none;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 20px rgba(0, 242, 255, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--text-main);
    padding: 0.8rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    border: var(--border-light);
    margin-left: var(--spacing-sm);
}

.btn-secondary:hover {
    background: var(--bg-card-hover);
}

/* Hero Section */
.hero {
    padding: 8rem 0 6rem;
    position: relative;
    text-align: center;
    overflow: hidden;
}

.hero-title {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
}

.text-gradient {
    background: var(--gradient-text);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto var(--spacing-lg);
}

/* Background Blobs */
.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
}

.glow-blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
}

.blob-1 {
    width: 400px;
    height: 400px;
    background: var(--secondary);
    top: -100px;
    left: -100px;
    animation: float 10s infinite alternate;
}

.blob-2 {
    width: 300px;
    height: 300px;
    background: var(--primary);
    bottom: 0;
    right: -50px;
    animation: float 8s infinite alternate-reverse;
}

@keyframes float {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

/* Sections */
.section-title {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

/* Cards Grid */
.grid-categories, .grid-resources {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.card {
    background: var(--bg-card);
    border: var(--border-light);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    transition: 0.3s ease;
    backdrop-filter: blur(5px);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.card:hover {
    background: var(--bg-card-hover);
    transform: translateY(-5px);
    border-color: var(--primary);
}

.category-card .icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.card p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Expandable Modules */
.modules-list {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-out, opacity 0.3s ease;
    opacity: 0;
    margin-top: 0;
}

.category-card.expanded .modules-list {
    max-height: 500px; /* Arbitrary large enough value */
    opacity: 1;
    margin-top: var(--spacing-sm);
}

.module-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    margin-bottom: 0.75rem;
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-md);
    color: var(--text-main);
    font-size: 0.9rem;
    border: 1px solid transparent;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.module-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 3px;
    background: transparent;
    transition: all 0.3s;
}

/* Module Icon */
.module-icon {
    font-size: 1.1rem;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
}

/* Module Name */
.module-name {
    flex: 1;
    font-weight: 500;
}

/* Status Badge */
.status-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    flex-shrink: 0;
}

/* Available State */
.module-item.available {
    cursor: pointer;
}

.module-item.available::before {
    background: var(--success-color);
}

.module-item.available .module-icon {
    color: var(--success-color);
}

.module-item.available .status-badge {
    background: rgba(0, 255, 136, 0.15);
    color: var(--success-color);
    border: 1px solid rgba(0, 255, 136, 0.3);
}

.module-item.available:hover {
    background: rgba(0, 255, 136, 0.08);
    border-color: var(--success-color);
    transform: translateX(8px);
}

.module-item.available:hover .module-name {
    color: var(--success-color);
}

.module-item.available:hover::before {
    width: 5px;
    box-shadow: 0 0 10px var(--success-color);
}

/* Coming Soon State */
.module-item.coming-soon {
    cursor: not-allowed;
    opacity: 0.6;
}

.module-item.coming-soon::before {
    background: var(--warning-color);
}

.module-item.coming-soon .module-icon {
    color: var(--warning-color);
}

.module-item.coming-soon .status-badge {
    background: rgba(255, 165, 0, 0.15);
    color: var(--warning-color);
    border: 1px solid rgba(255, 165, 0, 0.3);
}

.module-item.coming-soon:hover {
    opacity: 0.7;
    transform: none;
}

/* Locked/Disabled State (for future use) */
.module-item.locked {
    cursor: not-allowed;
    opacity: 0.4;
}

.module-item.locked::before {
    background: var(--disabled-color);
}

.module-item.locked .module-icon {
    color: var(--disabled-color);
}

.module-item.locked .status-badge {
    background: rgba(85, 85, 85, 0.15);
    color: var(--disabled-color);
    border: 1px solid rgba(85, 85, 85, 0.3);
}

.category-card {
    cursor: pointer;
    position: relative;
}

.category-card::after {
    content: '▼';
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    font-size: 0.8rem;
    color: var(--text-muted);
    transition: transform 0.3s;
}

.category-card.expanded::after {
    transform: rotate(180deg);
}

/* Resource Card Specifics */
.card-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    font-size: 0.85rem;
}

.tag {
    background: rgba(0, 242, 255, 0.1);
    color: var(--primary);
    padding: 0.2rem 0.6rem;
    border-radius: 20px;
}

.rating {
    color: #ffc107;
}

/* Footer */
.site-footer {
    padding: var(--spacing-lg) 0;
    border-top: var(--border-light);
    text-align: center;
    color: var(--text-muted);
    margin-top: var(--spacing-lg);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .main-nav {
        display: none; /* Simple hide for now, JS will handle toggle */
    }
}