/**
 * AI Connects Engineering - Blog Listing Stylesheet
 * Optimized for filtering with single unified grid
 */

:root {
    --primary: #0C1F3F;
    --accent: #00BCD4;
    --accent-dark: #0097a7;
    --accent-green: #00a888;
    --white: #ffffff;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-400: #94a3b8;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    --gradient-primary: linear-gradient(135deg, #0C1F3F 0%, #1E3A5F 100%);
}

/* ==========================================================================
   Skip Link
   ========================================================================== */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--accent);
    color: var(--white);
    padding: 8px 16px;
    z-index: 1000000;
    text-decoration: none;
    font-weight: 600;
    transition: top 0.2s ease;
}

.skip-link:focus {
    top: 0;
}

/* ==========================================================================
   Blog Hero
   ========================================================================== */
.blog-hero {
    background: var(--gradient-primary);
    padding: 8rem 2rem 3rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.blog-hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(30deg, transparent 48%, rgba(0, 163, 224, 0.03) 50%, transparent 52%),
        linear-gradient(-30deg, transparent 48%, rgba(0, 163, 224, 0.03) 50%, transparent 52%);
    background-size: 60px 100px;
    pointer-events: none;
}

.blog-hero-content {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.blog-hero h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 800;
    color: var(--white);
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.blog-hero p {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.6;
}

/* ==========================================================================
   Blog Section
   ========================================================================== */
.blog-section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem 4rem;
}

/* ==========================================================================
   Featured Article
   ========================================================================== */
.featured-article {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
    background: var(--white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
    margin-bottom: 3rem;
}

.featured-image {
    overflow: hidden;
}

.featured-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.featured-article:hover .featured-image img {
    transform: scale(1.03);
}

.featured-content {
    padding: 2.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.featured-badge {
    display: inline-block;
    background: var(--gradient-primary);
    color: var(--white);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
    width: fit-content;
}

.featured-content h2 {
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.featured-content h2 a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

.featured-content h2 a:hover {
    color: var(--accent);
}

.featured-content p {
    color: var(--gray-600);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

/* ==========================================================================
   Blog Meta
   ========================================================================== */
.blog-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
    font-size: 0.8rem;
}

.blog-category {
    background: rgba(0, 188, 212, 0.1);
    color: var(--accent-dark);
    padding: 0.25rem 0.625rem;
    border-radius: 4px;
    font-weight: 600;
}

.date {
    color: var(--gray-400);
}

.read-more {
    color: var(--accent-dark);
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    transition: gap 0.2s ease;
}

.read-more:hover {
    gap: 0.5rem;
}

/* ==========================================================================
   Filter Section
   ========================================================================== */
.filter-section {
    margin-bottom: 2rem;
}

.filter-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
    margin-bottom: 1rem;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 2px solid var(--gray-200);
    background: var(--white);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-600);
    cursor: pointer;
    transition: all 0.2s ease;
}

.filter-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.filter-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--white);
}

.article-count {
    text-align: center;
    color: var(--gray-400);
    font-size: 0.875rem;
}

/* ==========================================================================
   Articles Grid - SINGLE UNIFIED CONTAINER
   ========================================================================== */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

/* ==========================================================================
   Article Card
   ========================================================================== */
.article-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    transition: all 0.25s ease;
}

.article-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
}

/* Hidden state for filtering */
.article-card.hidden {
    display: none;
}

.card-link {
    display: block;
    text-decoration: none;
    color: inherit;
}

.card-image {
    overflow: hidden;
    aspect-ratio: 16/10;
}

.card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.article-card:hover .card-image img {
    transform: scale(1.05);
}

.card-content {
    padding: 1.25rem;
}

.card-content h3 {
    font-size: 1rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: 0.5rem;
    color: var(--primary);
    transition: color 0.2s ease;
}

.article-card:hover .card-content h3 {
    color: var(--accent);
}

.card-content p {
    color: var(--gray-600);
    font-size: 0.875rem;
    line-height: 1.5;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ==========================================================================
   No Results
   ========================================================================== */
.no-results {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--gray-400);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
    background: var(--gray-900);
    color: var(--gray-400);
    padding: 4rem 2rem 2rem;
}

.footer-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
    gap: 3rem;
}

.footer-brand {
    max-width: 280px;
}

.footer-brand .logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    margin-bottom: 1rem;
}

.footer-brand .logo img {
    height: 36px;
    width: auto;
}

.footer-brand .logo-text {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--white);
}

.footer-brand .logo-text span {
    color: var(--accent-green);
}

.footer-brand p {
    font-size: 0.9rem;
    line-height: 1.6;
}

.footer-title {
    color: var(--white);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

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

.footer-links a {
    color: var(--gray-400);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: var(--accent);
}

.footer-contact p {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
    font-size: 0.9rem;
    line-height: 1.5;
}

.footer-contact svg {
    flex-shrink: 0;
    margin-top: 2px;
    color: var(--accent);
}

.footer-contact a {
    color: var(--gray-400);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-contact a:hover {
    color: var(--accent);
}

.footer-bottom {
    max-width: 1200px;
    margin: 2.5rem auto 0;
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-800);
    text-align: center;
    font-size: 0.85rem;
}

.footer-bottom p {
    margin: 0.25rem 0;
}

/* ==========================================================================
   Mobile Navigation
   ========================================================================== */
@media (max-width: 768px) {
    .mobile-toggle {
        display: flex !important;
        flex-direction: column !important;
        gap: 5px !important;
        cursor: pointer !important;
        padding: 12px !important;
        min-width: 48px !important;
        min-height: 48px !important;
        justify-content: center !important;
        align-items: center !important;
        background: transparent !important;
        border: none !important;
        z-index: 10001 !important;
    }
    
    .mobile-toggle span {
        width: 24px !important;
        height: 2.5px !important;
        background: var(--primary) !important;
        display: block !important;
        border-radius: 2px !important;
        transition: all 0.3s ease !important;
    }
    
    .mobile-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(6px, 6px) !important;
    }
    
    .mobile-toggle.active span:nth-child(2) {
        opacity: 0 !important;
    }
    
    .mobile-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(6px, -6px) !important;
    }
    
    .nav-menu {
        display: flex !important;
        position: absolute !important;
        top: calc(100% + 8px) !important;
        right: 0 !important;
        left: auto !important;
        width: 220px !important;
        max-height: 0 !important;
        background: #ffffff !important;
        flex-direction: column !important;
        padding: 0 !important;
        opacity: 0 !important;
        visibility: hidden !important;
        transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1) !important;
        z-index: 9999 !important;
        list-style: none !important;
        border-radius: 12px !important;
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15) !important;
        overflow: hidden !important;
        transform: scale(0.95) translateY(-10px) !important;
        pointer-events: none !important;
        transform: scale(0.95) translateY(-10px) !important;
    }
    
    .nav-menu.active {
        display: flex !important;
        max-height: 500px !important;
        padding: 0.5rem 0 !important;
        opacity: 1 !important;
        visibility: visible !important;
        transform: scale(1) translateY(0) !important;
        pointer-events: auto !important;
    }
    
    .nav-menu li {
        border-bottom: 1px solid rgba(0, 0, 0, 0.05) !important;
        list-style: none !important;
    }
    
    .nav-menu li:last-child {
        border-bottom: none !important;
    }
    
    .nav-menu a {
        display: block !important;
        padding: 0.875rem 1.25rem !important;
        font-size: 0.9375rem !important;
        color: #1a1a2e !important;
        text-decoration: none !important;
    }
    
    .nav-menu .nav-cta {
        background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%) !important;
        color: white !important;
        border-radius: 8px !important;
        margin: 0.5rem 1rem 0.75rem !important;
        text-align: center !important;
    }
}

/* ==========================================================================
   Responsive - Tablet
   ========================================================================== */
@media (max-width: 1024px) {
    .articles-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 2rem;
    }
}

/* ==========================================================================
   Responsive - Mobile
   ========================================================================== */
@media (max-width: 768px) {
    .blog-hero {
        padding: 6rem 1rem 2rem;
    }
    
    .blog-hero h1 {
        font-size: 1.75rem;
    }
    
    .blog-hero p {
        font-size: 1rem;
    }
    
    .blog-section {
        padding: 2rem 1rem 3rem;
    }
    
    .featured-article {
        grid-template-columns: 1fr;
    }
    
    .featured-content {
        padding: 1.5rem;
    }
    
    .featured-content h2 {
        font-size: 1.25rem;
    }
    
    .filter-container {
        gap: 0.375rem;
    }
    
    .filter-btn {
        padding: 0.375rem 0.75rem;
        font-size: 0.8rem;
    }
    
    .articles-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .card-content {
        padding: 1rem;
    }
    
    .footer {
        padding: 3rem 1rem 2rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .footer-brand {
        max-width: 100%;
    }
    
    .footer-brand .logo {
        justify-content: center;
    }
    
    .footer-contact p {
        justify-content: center;
    }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */
@media print {
    .nav,
    .mobile-toggle,
    .filter-section,
    .footer,
    .skip-link {
        display: none !important;
    }
}

/* ==========================================================================
   Reduced Motion
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}