:root {
    --deep-blue: #1a237e;
    --accent-blue: #3f51b5;
    --accent-blue-light: #7986cb;
    --accent-blue-light-2: #c5cae9;
    --white: #ffffff;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-900: #212121;
    --text-primary: #212121;
    --text-secondary: #757575;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--white) 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

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

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 40px 0;
}

.title-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 16px;
}

.header-logo {
    height: 64px;
    width: auto;
}

h1 {
    font-size: 3rem;
    font-weight: 700;
    margin: 0;
    color: var(--deep-blue);
    background: linear-gradient(135deg, var(--deep-blue) 0%, var(--accent-blue) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.25rem;
    font-weight: 400;
    max-width: 600px;
    margin: 0 auto;
}

.header-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-top: 24px;
}

.header-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.875rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.website-btn {
    background: linear-gradient(135deg, var(--deep-blue) 0%, var(--accent-blue) 100%);
    color: var(--white);
    box-shadow: 0 4px 12px rgba(26, 35, 126, 0.3);
}

.website-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(26, 35, 126, 0.4);
}

.youtube-btn {
    background: linear-gradient(135deg, #ff0000 0%, #cc0000 100%);
    color: var(--white);
    box-shadow: 0 4px 12px rgba(255, 0, 0, 0.3);
}

.youtube-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 0, 0, 0.4);
}

.loading {
    text-align: center;
    padding: 60px 20px;
    font-size: 1.25rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.error {
    background: linear-gradient(135deg, #fee 0%, #ffebee 100%);
    border: 1px solid #ffcdd2;
    color: #c62828;
    padding: 20px;
    border-radius: 12px;
    margin: 24px 0;
    box-shadow: 0 2px 8px rgba(198, 40, 40, 0.1);
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
    margin-top: 40px;
    padding: 0 8px;
}

.content-card {
    background: var(--white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    border: 1px solid rgba(0, 0, 0, 0.04);
    position: relative;
}

.content-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--accent-blue-light-2) 0%, transparent 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.content-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12);
}

.content-card:hover::before {
    opacity: 0.05;
}

.thumbnail {
    width: 100%;
    height: 220px;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.content-card:hover .thumbnail {
    transform: scale(1.02);
}

.card-content {
    padding: 20px;
    position: relative;
    z-index: 1;
}

.card-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.4;
    letter-spacing: -0.01em;
}

.card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 16px;
}

.source-badge {
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.source-blog {
    background: linear-gradient(135deg, var(--accent-blue-light-2) 0%, var(--accent-blue-light) 100%);
    color: var(--deep-blue);
}

.source-youtube {
    background: linear-gradient(135deg, #ffebee 0%, #ffcdd2 100%);
    color: #c62828;
}

@media (max-width: 768px) {
    .container {
        padding: 16px;
    }
    
    header {
        padding: 20px 0;
        margin-bottom: 20px;
    }
    
    .title-container {
        flex-direction: column;
        gap: 12px;
    }
    
    .header-logo {
        height: 48px;
    }
    
    h1 {
        font-size: 2.25rem;
    }
    
    .subtitle {
        font-size: 1.125rem;
    }
    
    .header-buttons {
        flex-direction: column;
        align-items: center;
        gap: 12px;
    }
    
    .header-btn {
        padding: 10px 20px;
        font-size: 0.8rem;
    }
    
    .content-grid {
        grid-template-columns: 1fr;
        gap: 20px;
        margin-top: 32px;
        padding: 0;
    }
    
    .content-card {
        border-radius: 12px;
    }
    
    .card-content {
        padding: 16px;
    }
    
    .card-title {
        font-size: 1.1rem;
    }
    
    .loading {
        padding: 40px 20px;
        font-size: 1.125rem;
    }
}

/* Footer Styles */
.footer {
    background: transparent;
    color: var(--text-primary);
    margin-top: 40px;
    padding: 40px 0 20px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: center;
}

.footer-section h4 {
    font-size: 1.5625rem;
    font-weight: 700;
    margin-bottom: 25px;
    color: var(--text-primary);
    text-align: center;
}

.social-links {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    justify-content: center;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    background: var(--gray-100);
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.social-links a:hover {
    background: var(--accent-blue-light-2);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.social-icon {
    width: 25px;
    height: 25px;
    transition: all 0.3s ease;
}

.social-links a:hover .social-icon {
    transform: scale(1.1);
}

/* Footer Mobile Styles */
@media (max-width: 768px) {
    .footer {
        padding: 30px 0 20px;
        margin-top: 30px;
    }
    
    .footer-content {
        padding: 0 16px;
    }
    
    .footer-section h4 {
        font-size: 1.375rem;
    }
    
    .social-links {
        gap: 12px;
    }
    
    .social-links a {
        width: 45px;
        height: 45px;
    }
    
    .social-icon {
        width: 22px;
        height: 22px;
    }
}

/* Skeleton loading styles */
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.skeleton-card {
    background: var(--white);
    border-radius: 16px;
    padding: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    margin-bottom: 16px;
}

.skeleton-thumbnail {
    width: 100%;
    height: 200px;
    border-radius: 12px;
    margin-bottom: 16px;
}

.skeleton-title {
    height: 20px;
    border-radius: 4px;
    margin-bottom: 8px;
}

.skeleton-title.short {
    width: 70%;
}

.skeleton-meta {
    height: 16px;
    width: 40%;
    border-radius: 4px;
}