/**
 * AI Connects Engineering - Blog Stylesheet
 * Version: 5.0 - Matching working dropdown from blog-pcb-high-frequency-emc.html
 * 
 * Mobile nav uses !important to guarantee override of styles.css
 * This is acceptable practice when overriding a base stylesheet.
 */

/* ==========================================================================
   CSS Custom Properties
   ========================================================================== */
:root {
    --primary: #0a2540;
    --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, #0a2540 0%, #1a4a7a 100%);
    --gradient-accent: linear-gradient(135deg, #00BCD4 0%, #0097a7 100%);
    --shadow-dropdown: 0 10px 40px rgba(0, 0, 0, 0.15), 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* ==========================================================================
   Article Hero
   ========================================================================== */
.article-hero {
    background: var(--gradient-primary);
    padding: 8rem 2rem 2.5rem;
    color: var(--white);
}

.article-hero-content {
    max-width: 900px;
    margin: 0 auto;
}

/* Breadcrumb */
.breadcrumb {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    flex-wrap: wrap;
}

.breadcrumb a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

.breadcrumb span {
    color: var(--accent);
}

/* Category Badge */
.article-category {
    display: inline-block;
    background: var(--gradient-accent);
    color: var(--white);
    padding: 0.375rem 1rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

/* Hero Title */
.article-hero h1 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 800;
    color: var(--white);
    margin-bottom: 1rem;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

/* Article Meta */
.article-meta {
    display: flex;
    gap: 1.5rem;
    color: rgba(255, 255, 255, 0.65);
    font-size: 0.875rem;
    font-weight: 500;
}

/* ==========================================================================
   Article Content
   ========================================================================== */
.article-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2.5rem 2rem 3rem;
}

.article-content {
    font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--gray-700);
}

.article-content p {
    margin-bottom: 1.5rem;
}

.article-content h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary);
    margin: 2.5rem 0 1rem;
    line-height: 1.3;
}

.article-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary);
    margin: 1.75rem 0 0.75rem;
}

.article-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--primary);
    margin: 1.5rem 0 0.5rem;
}

.article-content ul,
.article-content ol {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
}

.article-content li {
    margin-bottom: 0.75rem;
}

.article-content li strong {
    color: var(--primary);
    font-weight: 600;
}

/* ==========================================================================
   Content Components
   ========================================================================== */

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
    margin: 1.5rem 0 2rem;
}

.feature-item {
    background: var(--gray-50);
    border-radius: 12px;
    padding: 1.5rem;
    border-left: 4px solid var(--accent);
}

.feature-item h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary);
    margin: 0 0 0.5rem 0;
}

.feature-item p {
    font-size: 0.9rem;
    color: var(--gray-600);
    margin: 0;
    line-height: 1.5;
}

/* Highlight Box */
.highlight-box {
    background: linear-gradient(135deg, #e0f7fa 0%, #b2ebf2 100%);
    border-left: 4px solid var(--accent);
    padding: 1.25rem 1.5rem;
    border-radius: 12px;
    margin: 2rem 0;
}

.highlight-box h4 {
    color: var(--primary);
    margin: 0 0 0.5rem 0;
    font-size: 1rem;
    font-weight: 600;
}

.highlight-box p {
    margin: 0;
    color: var(--gray-700);
    font-size: 0.95rem;
}

/* Workflow Box */
.workflow-box {
    background: var(--gray-50);
    padding: 1.25rem 1.5rem;
    border-radius: 12px;
    margin: 2rem 0;
    border-left: 4px solid var(--accent);
}

.workflow-box h3 {
    color: var(--primary);
    margin: 0 0 0.75rem 0;
    font-size: 1.125rem;
    font-weight: 600;
}

.workflow-box p {
    margin: 0;
    font-size: 0.95rem;
    color: var(--gray-700);
}

/* ==========================================================================
   CTA Box
   ========================================================================== */
.cta-box {
    background: var(--gradient-primary);
    padding: 2.5rem;
    border-radius: 16px;
    text-align: center;
    margin: 2.5rem 0;
}

.cta-box h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 0 0.75rem 0;
    color: #ffffff;
}

.cta-box p {
    margin: 0 0 1.5rem 0;
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.9);
}

.btn-primary,
.cta-box .btn-primary {
    display: inline-block;
    background: var(--accent);
    color: #ffffff;
    padding: 0.875rem 2rem;
    border-radius: 10px;
    text-decoration: none;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
}

.btn-primary:hover,
.cta-box .btn-primary:hover {
    background: var(--accent-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 188, 212, 0.3);
}

/* ==========================================================================
   Skip Link (Accessibility)
   ========================================================================== */
.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;
}

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

/* ==========================================================================
   Mobile Navigation (768px and below)
   Uses !important to override styles.css - matching working pattern
   ========================================================================== */
@media (max-width: 768px) {
    /* Mobile Toggle - Always visible on mobile */
    .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;
    }
    
    /* Hamburger Animation */
    .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;
    }
    
    /* Dropdown Menu - Closed State */
    .nav-menu {
        position: absolute !important;
        top: calc(100% + 8px) !important;
        right: 0 !important;
        left: auto !important;
        bottom: 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: var(--shadow-dropdown) !important;
        overflow: hidden !important;
        transform: scale(0.95) translateY(-10px) !important;
    }
    
    /* Dropdown Menu - Open State */
    .nav-menu.active {
        max-height: 500px !important;
        padding: 0.5rem 0 !important;
        opacity: 1 !important;
        visibility: visible !important;
        transform: scale(1) translateY(0) !important;
    }
    
    /* Menu Items */
    .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;
    }
    
    /* Menu Links */
    .nav-menu a {
        display: block !important;
        padding: 0.875rem 1.25rem !important;
        font-size: 0.9375rem !important;
        color: #1a1a2e !important;
        text-decoration: none !important;
        background: transparent !important;
        transition: background 0.2s ease, color 0.2s ease !important;
    }
    
    .nav-menu a:hover {
        background: var(--gray-100) !important;
        color: var(--accent) !important;
    }
    
    .nav-menu a.active {
        color: var(--accent) !important;
        background: rgba(0, 188, 212, 0.08) !important;
    }
    
    /* CTA Button in Menu */
    .nav-menu .nav-cta {
        background: var(--gradient-accent) !important;
        color: white !important;
        border-radius: 8px !important;
        margin: 0.5rem 1rem 0.75rem !important;
        text-align: center !important;
    }
    
    .nav-menu .nav-cta:hover {
        background: linear-gradient(135deg, #0097a7 0%, #00838f 100%) !important;
        color: white !important;
    }
    
    /* Article Hero - Mobile */
    .article-hero {
        padding: 6rem 1rem 2rem;
    }
    
    .article-hero h1 {
        font-size: 1.5rem;
    }
    
    .article-meta {
        flex-direction: column;
        gap: 0.25rem;
    }
    
    .article-container {
        padding: 2rem 1rem 2.5rem;
    }
    
    .article-content {
        font-size: 1rem;
    }
    
    .article-content h2 {
        font-size: 1.375rem;
        margin: 2rem 0 0.75rem;
    }
    
    .article-content h3 {
        font-size: 1.125rem;
    }
    
    /* Feature Grid - Mobile */
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    /* CTA Box - Mobile */
    .cta-box {
        padding: 2rem 1.5rem;
        margin: 2rem 0;
    }
    
    .cta-box h3 {
        font-size: 1.25rem;
    }
}

/* ==========================================================================
   Tablet (769px - 1024px)
   ========================================================================== */
@media (min-width: 769px) and (max-width: 1024px) {
    .article-hero {
        padding: 7rem 1.5rem 2rem;
    }
    
    .article-hero h1 {
        font-size: 2rem;
    }
    
    .article-container {
        padding: 2.25rem 1.5rem 2.75rem;
    }
}

/* ==========================================================================
   Footer - Matching index.html structure
   ========================================================================== */
.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;
    color: var(--gray-400);
}

.footer-title {
    color: var(--white);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
}

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

.footer-links li {
    margin-bottom: 0.625rem;
}

.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: 3rem auto 0;
    padding-top: 2rem;
    border-top: 1px solid var(--gray-800);
    text-align: center;
    font-size: 0.85rem;
    color: var(--gray-400);
}

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

/* Footer Mobile */
@media (max-width: 768px) {
    .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;
    }
    
    .footer-bottom {
        margin-top: 2rem;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 2rem;
    }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */
@media print {
    .nav,
    .mobile-toggle,
    .cta-box,
    .footer,
    .skip-link {
        display: none !important;
    }
    
    .article-hero {
        background: none !important;
        color: #000 !important;
        padding: 1rem 0 !important;
    }
    
    .article-category {
        background: none !important;
        color: #000 !important;
        border: 1px solid #000 !important;
    }
}

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