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

:root {
    --primary-color: hsl(175, 70%, 50%);
    --primary-dark: hsl(175, 70%, 40%);
    --secondary-color: hsl(220, 15%, 25%);
    --accent-color: hsl(45, 95%, 60%);
    --text-primary: hsl(220, 15%, 15%);
    --text-secondary: hsl(220, 10%, 50%);
    --text-light: hsl(220, 15%, 70%);
    --bg-primary: hsl(0, 0%, 100%);
    --bg-secondary: hsl(220, 15%, 97%);
    --bg-card: hsl(0, 0%, 100%);
    --border-color: hsl(220, 15%, 90%);
    --shadow-light: 0 2px 8px hsla(220, 15%, 0%, 0.08);
    --shadow-medium: 0 4px 16px hsla(220, 15%, 0%, 0.12);
    --shadow-heavy: 0 8px 32px hsla(220, 15%, 0%, 0.16);
    --border-radius: 8px;
    --border-radius-lg: 12px;
    --transition: all 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

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

/* Header Styles */
.header {
    background: var(--bg-card);
    box-shadow: var(--shadow-light);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 20px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
}

.nav-logo {
    width: 32px;
    height: 32px;
}

.nav-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 0;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--primary-color);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    gap: 0.25rem;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

/* Button Styles */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 0.95rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background: hsl(220, 15%, 20%);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 60vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--bg-secondary), var(--bg-primary));
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0.1;
    z-index: 1;
}

.hero-bg-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 600px;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Section Styles */
.featured-section,
.categories-preview {
    padding: 4rem 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.section-footer {
    text-align: center;
    margin-top: 3rem;
}

/* Video Grid */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.video-card {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-light);
    overflow: hidden;
    transition: var(--transition);
}

.video-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
}

.video-thumbnail {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
}

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

.video-duration {
    position: absolute;
    bottom: 0.5rem;
    right: 0.5rem;
    background: hsla(0, 0%, 0%, 0.8);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 500;
}

.video-content {
    padding: 1.5rem;
}

.video-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    line-height: 1.3;
    color: var(--text-primary);
}

.video-channel {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 0.75rem;
}

.video-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-size: 0.85rem;
}

.video-views {
    color: var(--text-light);
}

.video-category {
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.video-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.video-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
}

.video-link:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

/* Categories Grid */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
}

.category-card {
    background: var(--bg-card);
    padding: 2rem 1.5rem;
    border-radius: var(--border-radius-lg);
    text-decoration: none;
    color: var(--text-primary);
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    text-align: center;
    border: 2px solid transparent;
}

.category-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
    border-color: var(--primary-color);
}

.category-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.category-card p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.category-count {
    display: inline-block;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* Search and Filter Styles */
.search-section {
    background: var(--bg-secondary);
    padding: 2rem 0;
}

.search-form {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.search-input {
    flex: 1;
    min-width: 250px;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px hsla(175, 70%, 50%, 0.1);
}

.filter-select {
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    background: white;
    cursor: pointer;
    transition: var(--transition);
}

.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.filters-section {
    padding: 2rem 0;
    background: var(--bg-secondary);
}

.filters-container {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    align-items: center;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.filter-group label {
    font-weight: 500;
    color: var(--text-secondary);
}

/* Video Detail Styles */
.video-detail {
    padding: 2rem 0;
}

.video-player {
    max-width: 800px;
    margin: 0 auto 2rem;
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-medium);
}

.video-embed {
    position: relative;
    width: 100%;
    height: 450px;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

.video-info {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-light);
}

.video-info h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.video-info-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.video-info-channel {
    font-size: 1.1rem;
    color: var(--primary-color);
    font-weight: 600;
}

.video-info-stats {
    display: flex;
    gap: 1rem;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.video-description-full {
    line-height: 1.7;
    color: var(--text-primary);
    margin-bottom: 2rem;
}

.video-topics {
    margin-bottom: 2rem;
}

.video-topics h3 {
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.topics-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.topic-tag {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.content-disclaimer {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--primary-color);
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Footer Styles */
.footer {
    background: var(--secondary-color);
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: hsl(220, 15%, 80%);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    border-top: 1px solid hsl(220, 15%, 35%);
    padding-top: 1rem;
    text-align: center;
    color: hsl(220, 15%, 70%);
}

.disclaimer-text {
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* Page Content Styles */
.page-content {
    padding: 3rem 0;
    max-width: 800px;
    margin: 0 auto;
}

.page-content h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.page-content h2 {
    font-size: 1.8rem;
    font-weight: 600;
    margin: 2rem 0 1rem;
    color: var(--text-primary);
}

.page-content h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin: 1.5rem 0 0.75rem;
    color: var(--text-primary);
}

.page-content p {
    margin-bottom: 1rem;
    line-height: 1.7;
    color: var(--text-primary);
}

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

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

.contact-info {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    margin: 2rem 0;
}

.contact-info h3 {
    color: var(--primary-color);
    margin-top: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--bg-card);
        box-shadow: var(--shadow-medium);
        flex-direction: column;
        padding: 1rem 0;
        gap: 0;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-link {
        padding: 1rem 2rem;
        width: 100%;
        text-align: left;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .video-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .categories-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }

    .search-form {
        flex-direction: column;
    }

    .search-input {
        min-width: auto;
    }

    .video-embed {
        height: 250px;
    }

    .video-info-meta {
        flex-direction: column;
        align-items: flex-start;
    }

    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .video-content {
        padding: 1rem;
    }

    .category-card {
        padding: 1.5rem 1rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}