:root {
    --primary-color: #333;
    --secondary-color: #555;
    --accent-color: #ff4444;
    --background-color: #f0f4f8;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --transition-speed: 0.3s;
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    background: linear-gradient(135deg, var(--background-color) 0%, #e0e8f0 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    padding: 1.5rem;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin: 0;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

nav li a {
    color: var(--primary-color);
    text-decoration: none;
    padding: 0.75rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border-radius: 6px;
    transition: all var(--transition-speed) ease;
}

nav li a:hover {
    color: var(--accent-color);
    background-color: rgba(255, 68, 68, 0.1);
    transform: translateY(-2px);
}

/* Main Content */
main {
    flex: 1;
    padding: 2rem 1rem;
}

.videos-section {
    max-width: 1200px;
    margin: 0 auto;
}

h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

/* Video Grid */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.video-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: transform var(--transition-speed) ease;
}

.video-card:hover {
    transform: translateY(-5px);
}

.video-iframe {
    width: 100%;
    aspect-ratio: 16/9;
    border: none;
}

.video-info {
    padding: 1.5rem;
    background: linear-gradient(to bottom, rgba(255, 255, 255, 0.95), white);
}

.video-info h3 {
    font-size: 1.25rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.video-info p {
    color: var(--secondary-color);
    font-size: 0.95rem;
}

/* Footer */
footer {
    background: linear-gradient(135deg, var(--primary-color) 0%, rgba(51, 51, 51, 0.9) 100%);
    color: white;
    padding: 2rem 1rem;
    margin-top: auto;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

/* Responsive */
@media (max-width: 1200px) {
    .video-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
    }
    
    nav ul {
        gap: 1rem;
    }
}

@media (max-width: 768px) {
    .video-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 1rem;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    nav ul {
        flex-direction: column;
        gap: 0.75rem;
    }
    
    nav li a {
        padding: 0.5rem 1rem;
    }
}

@media (max-width: 480px) {
    .video-grid {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    
    .video-card {
        aspect-ratio: 1.5/1;
    }
    
    header {
        padding: 1rem;
    }
    
    h1 {
        font-size: 1.75rem;
    }
    
    .video-info h3 {
        font-size: 1.1rem;
    }
    
    .video-info p {
        font-size: 0.85rem;
    }
}