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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #fff;
}

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

/* Header */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: #333;
    font-weight: 700;
    font-size: 1.2rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-link {
    text-decoration: none;
    color: #666;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-link:hover,
.nav-link.active {
    color: #e74c3c;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    transition: 0.3s;
}

/* Hero */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 80px 20px;
    display: flex;
    align-items: center;
    min-height: 500px;
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    z-index: 2;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    font-weight: 700;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.hero-bg {
    position: absolute;
    right: -100px;
    top: 50%;
    transform: translateY(-50%);
    opacity: 0.1;
    z-index: 1;
}

.hero-bg img {
    width: 600px;
    height: auto;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 30px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    transition: all 0.3s;
    border: 2px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background: #e74c3c;
    color: white;
    border-color: #e74c3c;
}

.btn-primary:hover {
    background: #c0392b;
    border-color: #c0392b;
}

.btn-outline {
    background: transparent;
    color: #e74c3c;
    border-color: #e74c3c;
}

.btn-outline:hover {
    background: #e74c3c;
    color: white;
}

/* Video Grid */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 50px;
}

.video-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    text-decoration: none;
    color: inherit;
}

.video-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.video-thumbnail {
    position: relative;
    aspect-ratio: 16/9;
    overflow: hidden;
}

.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.video-duration {
    position: absolute;
    bottom: 8px;
    right: 8px;
    background: rgba(0,0,0,0.8);
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
}

.video-info {
    padding: 20px;
}

.video-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
    line-height: 1.3;
}

.video-channel {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.video-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: #999;
}

.video-category {
    background: #f8f9fa;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    color: #666;
}

/* Sections */
.featured,
.categories-preview {
    padding: 80px 0;
}

.featured h2,
.categories-preview h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: #333;
}

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

/* Categories Grid */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.category-card {
    background: white;
    padding: 40px 30px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    text-align: center;
    text-decoration: none;
    color: inherit;
    transition: transform 0.3s, box-shadow 0.3s;
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.category-card h3 {
    font-size: 1.4rem;
    margin-bottom: 12px;
    color: #e74c3c;
}

.category-card p {
    color: #666;
}

/* Search & Filter */
.search-section {
    background: #f8f9fa;
    padding: 40px 0;
}

.search-controls {
    display: flex;
    gap: 20px;
    align-items: center;
    flex-wrap: wrap;
}

.search-input {
    flex: 1;
    min-width: 250px;
    padding: 12px 16px;
    border: 2px solid #ddd;
    border-radius: 6px;
    font-size: 1rem;
}

.search-input:focus {
    outline: none;
    border-color: #e74c3c;
}

.filter-select {
    padding: 12px 16px;
    border: 2px solid #ddd;
    border-radius: 6px;
    font-size: 1rem;
    background: white;
}

.filter-select:focus {
    outline: none;
    border-color: #e74c3c;
}

/* Video Detail */
.video-detail {
    padding: 40px 0;
}

.video-player {
    aspect-ratio: 16/9;
    background: #000;
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 30px;
}

.video-player iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.video-detail-info h1 {
    font-size: 2rem;
    margin-bottom: 15px;
}

.video-detail-meta {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.video-detail-meta span {
    color: #666;
}

.video-description {
    line-height: 1.8;
    color: #555;
    margin-bottom: 30px;
}

.video-topics {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.topic-tag {
    background: #f0f0f0;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.9rem;
    color: #666;
}

/* Footer */
.footer {
    background: #2c3e50;
    color: white;
    padding: 50px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 20px;
    color: #ecf0f1;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 8px;
}

.footer-section a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: #e74c3c;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #34495e;
    color: #95a5a6;
}

/* Contact Form */
.contact-form {
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #333;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #ddd;
    border-radius: 6px;
    font-size: 1rem;
    font-family: inherit;
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #e74c3c;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .video-grid {
        grid-template-columns: 1fr;
    }
    
    .search-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .search-input {
        min-width: auto;
    }
    
    .video-detail-meta {
        flex-direction: column;
        gap: 10px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 60px 15px;
    }
    
    .featured,
    .categories-preview {
        padding: 60px 0;
    }
    
    .video-info {
        padding: 15px;
    }
}

/* Page Content */
.page-content {
    padding: 40px 0;
    min-height: 60vh;
}

.page-header {
    text-align: center;
    margin-bottom: 50px;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: #333;
}

.page-header p {
    font-size: 1.1rem;
    color: #666;
    max-width: 600px;
    margin: 0 auto;
}

.content-section {
    margin-bottom: 40px;
}

.content-section h2 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: #333;
}

.content-section h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: #444;
}

.content-section p {
    margin-bottom: 15px;
    line-height: 1.7;
    color: #555;
}

.content-section ul,
.content-section ol {
    margin-bottom: 15px;
    padding-left: 30px;
}

.content-section li {
    margin-bottom: 8px;
    line-height: 1.6;
    color: #555;
}