/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #ffffff;
    background-color: #1a1a1a;
    position: relative;
}

/* Video Background */
#background-video {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: -1;
    opacity: 0.3;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: #1a1a1a url('images/header-background.png') center center;
    background-size: cover;
    background-repeat: no-repeat;
    color: white;
    padding: 2rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: relative;
    z-index: 1;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at center, rgba(0, 0, 0, 0.9) 0%, rgba(0, 0, 0, 0.7) 40%, rgba(0, 0, 0, 0.4) 70%, rgba(0, 0, 0, 0.2) 100%);
    z-index: -1;
}

.header-content {
    text-align: center;
}

.logo {
    font-size: 3.5rem;
    font-weight: 300;
    margin-bottom: 0.2rem;
    letter-spacing: 0.15em;
    font-family: 'Orbitron', 'Audiowide', 'Rajdhani', 'Chakra Petch', 'Exo 2', monospace;
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(102, 126, 234, 0.3);
    text-transform: uppercase;
    font-style: normal;
}

.logo a {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(102, 126, 234, 0.3);
    text-decoration: none;
    transition: all 0.3s ease;
    font-family: 'Orbitron', 'Audiowide', 'Rajdhani', 'Chakra Petch', 'Exo 2', monospace;
    text-transform: uppercase;
    font-weight: 300;
    letter-spacing: 0.15em;
}

.logo a:hover {
    text-shadow: 0 0 40px rgba(102, 126, 234, 0.5);
    transform: scale(1.02);
}

.logo::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    opacity: 0.8;
    z-index: -1;
}

.tagline {
    font-size: 0.85rem;
    font-weight: 400;
    font-style: italic;
    opacity: 0.8;
    color: #ffffff;
    margin-top: 0;
}

/* Main Content */
.main {
    padding: 0;
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 4rem;
    padding: 4rem 0;
    background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 50%, #1a1a1a 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(102, 126, 234, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(118, 75, 162, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(102, 126, 234, 0.05) 0%, transparent 50%);
    pointer-events: none;
}

.hero > * {
    position: relative;
    z-index: 1;
}

.hero h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #ffffff;
    line-height: 1.2;
}

.hero-description {
    font-size: 1.2rem;
    color: #cccccc;
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Categories Section */
.categories h3 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 2rem;
    text-align: center;
    color: #ffffff;
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.category-card {
    background: #2d2d2d;
    border: 1px solid #404040;
    border-radius: 12px;
    padding: 1.5rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.category-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
    border-color: #667eea;
}

.category-card h4 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: #ffffff;
}

.category-card h4 a {
    color: #667eea;
    text-decoration: none;
    transition: color 0.3s ease;
}

.category-card h4 a:hover {
    color: #5a6fd8;
    text-decoration: underline;
}

.category-card p {
    color: #cccccc;
    font-size: 0.95rem;
    line-height: 1.5;
}

/* Article Lists */
.article-list {
    margin: 0;
}

.category-hero {
    text-align: center;
    margin-bottom: 3rem;
    padding: 3rem 0;
    background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 50%, #1a1a1a 100%);
    position: relative;
    overflow: hidden;
}

.category-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(102, 126, 234, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(118, 75, 162, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(102, 126, 234, 0.05) 0%, transparent 50%);
    pointer-events: none;
}

.category-hero > * {
    position: relative;
    z-index: 1;
}

.category-hero h3 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #ffffff;
    line-height: 1.2;
}

.category-hero .category-description {
    font-size: 1.2rem;
    color: #cccccc;
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.6;
}

.article-list h3 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #ffffff;
    border-bottom: 2px solid #667eea;
    padding-bottom: 0.5rem;
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.article-item {
    background: #2d2d2d;
    border: 1px solid #404040;
    border-radius: 8px;
    padding: 1.25rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

.article-item:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.1);
    border-color: #667eea;
}

.article-item h4 {
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.article-item h4 a {
    color: #ffffff;
    text-decoration: none;
    transition: color 0.3s ease;
}

.article-item h4 a:hover {
    color: #667eea;
}

.article-item .article-number {
    color: #667eea;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

/* Article Content */
.article-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 0;
}

.article-header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid #e1e5e9;
}

.article-header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #ffffff;
    line-height: 1.2;
}

.article-meta {
    color: #cccccc;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.article-content h2 {
    font-size: 1.6rem;
    font-weight: 600;
    margin: 2rem 0 1rem 0;
    color: #ffffff;
}

.article-content h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin: 1.5rem 0 0.75rem 0;
    color: #ffffff;
}

.article-content p {
    margin-bottom: 1rem;
    line-height: 1.7;
    color: #e0e0e0;
}

.article-content ul, .article-content ol {
    margin: 1rem 0;
    padding-left: 2rem;
}

.article-content li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

.article-content blockquote {
    border-left: 4px solid #667eea;
    padding-left: 1rem;
    margin: 1.5rem 0;
    font-style: italic;
    color: #cccccc;
}

.article-content code {
    background-color: #f8f9fa;
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.9rem;
}

.article-content pre {
    background-color: #f8f9fa;
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1rem 0;
    border: 1px solid #e1e5e9;
}

.article-content pre code {
    background: none;
    padding: 0;
}

/* Navigation */
.nav-breadcrumb {
    margin-bottom: 2rem;
    padding: 1rem 0;
    border-bottom: 1px solid #e1e5e9;
}

.nav-breadcrumb a {
    color: #667eea;
    text-decoration: none;
    font-size: 0.9rem;
}

.nav-breadcrumb a:hover {
    text-decoration: underline;
}

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.3s ease;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.back-to-top.visible {
    opacity: 1;
}

.back-to-top:hover {
    background: #5a6fd8;
}

/* Footer */
.footer {
    background: #2d2d2d;
    padding: 2rem 0;
    margin-top: 4rem;
    border-top: 1px solid #404040;
    text-align: center;
}

.footer p {
    color: #cccccc;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .logo {
        font-size: 2rem;
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .hero-description {
        font-size: 1.1rem;
    }
    
    .category-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .article-grid {
        grid-template-columns: 1fr;
    }
    
    .article-header h1 {
        font-size: 1.8rem;
    }
    
    .article-content h2 {
        font-size: 1.4rem;
    }
    
    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 1.5rem 0;
    }
    
    .logo {
        font-size: 1.8rem;
    }
    
    .tagline {
        font-size: 1rem;
    }
    
    .hero h2 {
        font-size: 1.6rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .category-card {
        padding: 1.25rem;
    }
    
    .article-item {
        padding: 1rem;
    }
}

/* Print Styles */
@media print {
    .header, .footer, .back-to-top {
        display: none;
    }
    
    .main {
        padding: 0;
    }
    
    .article-content {
        max-width: none;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for accessibility */
a:focus, button:focus {
    outline: 2px solid #667eea;
    outline-offset: 2px;
}

/* Dark mode support - now default */
@media (prefers-color-scheme: light) {
    body {
        background-color: #ffffff;
        color: #1a1a1a;
    }
    
    .category-card, .article-item {
        background: white;
        border-color: #e1e5e9;
        color: #1a1a1a;
    }
    
    .article-content {
        color: #333;
    }
    
    .article-content h1, .article-content h2, .article-content h3 {
        color: #1a1a1a;
    }
    
    .footer {
        background: #f8f9fa;
        border-color: #e1e5e9;
    }
    
    .hero h2 {
        color: #1a1a1a;
    }
    
    .hero-description {
        color: #666;
    }
    
    .categories h3 {
        color: #1a1a1a;
    }
    
    .category-card h4 {
        color: #1a1a1a;
    }
    
    .category-card p {
        color: #666;
    }
    
    .article-list h3 {
        color: #1a1a1a;
    }
    
    .article-item h4 a {
        color: #1a1a1a;
    }
    
    .article-header h1 {
        color: #1a1a1a;
    }
    
    .article-meta {
        color: #666;
    }
    
    .article-content h2, .article-content h3 {
        color: #1a1a1a;
    }
    
    .article-content p {
        color: #333;
    }
    
    .article-content blockquote {
        color: #555;
    }
    
    .footer p {
        color: #666;
    }
}