/* ===== CSS RESET & BASE STYLES ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary-blue: #8bbfbc;
    --accent-blue: #00509e;
    --red-accent: #8bbfbc;
    --light-blue: #e8f2ff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --white: #ffffff;
    --green-500: #10b981;
    --orange-500: #f59e0b;
    --purple-500: #8b5cf6;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Border radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--gray-50);
    font-size: var(--font-size-base);
    overflow-x: hidden;
}

/* ===== HEADER STYLES ===== */
.hero-header {
    background: linear-gradient(135deg, var(--accent-blue) 0%, var(--primary-blue) 100%);
    color: var(--white);
    padding: var(--spacing-2xl) 0;
    position: relative;
    overflow: hidden;
}

.hero-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="0.5" fill="rgba(255,255,255,0.05)"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.1;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
    position: relative;
    z-index: 1;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.header-logo {
    height: 56px;
    width: auto;
    filter: brightness(1.1);
    transition: transform var(--transition-normal);
}

.header-logo:hover {
    transform: scale(1.05);
}

.header-text h1 {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    line-height: 1.2;
    letter-spacing: -0.025em;
}

.workshop-details {
    display: flex;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.detail-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-lg);
    font-weight: 500;
}

.detail-item i {
    color: var(--light-blue);
    font-size: var(--font-size-xl);
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--red-accent);
    color: var(--white);
    padding: var(--spacing-lg) var(--spacing-2xl);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-lg);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-lg);
    border: 2px solid transparent;
}

.cta-button:hover {
    background: #a50829;
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(255, 255, 255, 0.2);
}

/* ===== NAVIGATION STYLES ===== */
.main-nav {
    background: var(--red-accent);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
}

.nav-links {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: var(--spacing-2xl);
    padding: var(--spacing-lg) 0;
}

.nav-link {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--font-size-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-1px);
}

.nav-link i {
    font-size: var(--font-size-base);
}

/* ===== MAIN CONTENT STYLES ===== */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-2xl) var(--spacing-xl);
}

.content-section {
    background: var(--white);
    margin: var(--spacing-3xl) 0;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-3xl);
    transition: transform var(--transition-normal);
}

.content-section:hover {
    transform: translateY(-2px);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-header h2 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.025em;
}

.section-line {
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-blue), var(--red-accent));
    margin: 0 auto var(--spacing-lg);
    border-radius: var(--radius-sm);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--gray-600);
    font-style: italic;
}

/* ===== ABOUT SECTION STYLES ===== */
.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.about-card {
    background: var(--gray-50);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-normal);
    border: 2px solid transparent;
}

.about-card:hover {
    background: var(--white);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--light-blue);
}

.card-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--accent-blue), var(--primary-blue));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-lg);
    transition: transform var(--transition-normal);
}

.about-card:hover .card-icon {
    transform: scale(1.1) rotate(5deg);
}

.card-icon i {
    font-size: var(--font-size-2xl);
    color: var(--white);
}

.about-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-md);
}

.about-description {
    font-size: var(--font-size-lg);
    line-height: 1.8;
    color: var(--gray-700);
    text-align: left;
    max-width: 800px;
    margin: 0 auto;
}

/* ===== SPEAKERS SECTION STYLES ===== */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.speaker-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-md);
    border: 2px solid transparent;
}

.speaker-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--light-blue);
}

.speaker-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 1;
}

.speaker-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.speaker-card:hover .speaker-image img {
    transform: scale(1.1);
}

.speaker-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(4, 42, 105, 0.8), rgba(0, 80, 158, 0.8));
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.speaker-card:hover .speaker-overlay {
    opacity: 1;
}

.speaker-links {
    display: flex;
    gap: var(--spacing-md);
}

.speaker-link {
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-blue);
    text-decoration: none;
    transition: all var(--transition-fast);
    transform: translateY(20px);
}

.speaker-card:hover .speaker-link {
    transform: translateY(0);
}

.speaker-link:hover {
    background: var(--white);
    transform: scale(1.1);
}

.speaker-info {
    padding: var(--spacing-xl);
    text-align: center;
}

.speaker-info h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-sm);
}

.speaker-affiliation {
    font-size: var(--font-size-lg);
    font-weight: 500;
    color: var(--accent-blue);
    margin-bottom: var(--spacing-sm);
}

.speaker-expertise {
    font-size: var(--font-size-sm);
    color: var(--gray-600);
    font-style: italic;
}

/* ===== SCHEDULE SECTION STYLES ===== */
.schedule-timeline {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.talk-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: all var(--transition-normal);
    border-left: 5px solid var(--gray-200);
    cursor: pointer;
    position: relative;
}

.talk-card.opening {
    border-left-color: var(--green-500);
}

.talk-card.primer {
    border-left-color: var(--accent-blue);
}

.talk-card.break {
    border-left-color: var(--orange-500);
}

.talk-card.technical {
    border-left-color: var(--primary-blue);
}

.talk-card.closing {
    border-left-color: var(--purple-500);
}

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

.talk-card.hovered .talk-abstract {
    max-height: 400px;
    opacity: 1;
    padding: var(--spacing-lg) var(--spacing-xl) var(--spacing-xl);
}

.talk-card {
    display: grid;
    grid-template-columns: 200px 1fr;
    min-height: 120px;
}

.talk-time {
    background: var(--gray-50);
    padding: var(--spacing-xl);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    border-right: 1px solid var(--gray-200);
}

.time {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-sm);
}

.duration {
    font-size: var(--font-size-sm);
    color: var(--gray-600);
    background: var(--gray-200);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-weight: 500;
}

.talk-content {
    padding: var(--spacing-xl);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.talk-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--spacing-lg);
}

.talk-header h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--primary-blue);
    line-height: 1.3;
}

.talk-speakers {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    align-items: center;
}

.speaker-tag {
    background: var(--light-blue);
    color: var(--primary-blue);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    white-space: nowrap;
}

.speaker-tag.networking {
    background: var(--orange-500);
    color: var(--white);
}

.talk-summary {
    color: var(--gray-700);
    font-size: var(--font-size-base);
    line-height: 1.6;
}

.talk-abstract {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: all var(--transition-slow);
    background: var(--gray-50);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-md);
}

.talk-abstract h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-md);
}

.talk-abstract p {
    color: var(--gray-700);
    line-height: 1.7;
    font-size: var(--font-size-base);
}

.talk-actions {
    margin-top: var(--spacing-lg);
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.slides-btn {
    background: var(--accent-blue);
    color: var(--white);
    border: none;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-normal);
}

.slides-btn:hover {
    background: var(--primary-blue);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* ===== REFERENCES SECTION STYLES ===== */
.references-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.reference-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    border: 2px solid transparent;
    display: flex;
    gap: var(--spacing-lg);
}

.reference-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--light-blue);
}

.reference-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--accent-blue), var(--primary-blue));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: transform var(--transition-normal);
}

.reference-card:hover .reference-icon {
    transform: scale(1.1) rotate(5deg);
}

.reference-icon i {
    font-size: var(--font-size-xl);
    color: var(--white);
}

.reference-content h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
}

.reference-authors {
    font-size: var(--font-size-sm);
    color: var(--gray-600);
    margin-bottom: var(--spacing-xs);
}

.reference-year {
    font-size: var(--font-size-sm);
    color: var(--accent-blue);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.reference-description {
    font-size: var(--font-size-sm);
    color: var(--gray-700);
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
}

.reference-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--accent-blue);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: all var(--transition-normal);
}

.reference-link:hover {
    color: var(--primary-blue);
    transform: translateX(2px);
}

/* ===== FOOTER STYLES ===== */
.site-footer {
    background: var(--primary-blue);
    color: var(--white);
    padding: var(--spacing-2xl) 0;
    margin-top: var(--spacing-3xl);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

.footer-links {
    display: flex;
    gap: var(--spacing-xl);
}

.footer-links a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-normal);
}

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

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 1024px) {
    .header-content {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-lg);
    }
    
    .workshop-details {
        justify-content: center;
    }
    
    .talk-card {
        grid-template-columns: 1fr;
    }
    
    .talk-time {
        border-right: none;
        border-bottom: 1px solid var(--gray-200);
    }
}

@media (max-width: 768px) {
    .main-content {
        padding: var(--spacing-xl) var(--spacing-md);
    }
    
    .content-section {
        padding: var(--spacing-xl);
        margin: var(--spacing-xl) 0;
    }
    
    .header-content {
        padding: 0 var(--spacing-md);
    }
    
    .nav-container {
        padding: 0 var(--spacing-md);
    }
    
    .nav-links {
        gap: var(--spacing-md);
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .header-text h1 {
        font-size: var(--font-size-2xl);
    }
    
    .workshop-details {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .speakers-grid {
        grid-template-columns: 1fr;
    }
    
    .references-grid {
        grid-template-columns: 1fr;
    }
    
    .reference-card {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .nav-links {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .nav-link {
        justify-content: center;
        padding: var(--spacing-md);
    }
    
    .cta-button {
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: var(--font-size-base);
    }
    
    .talk-header {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}

/* ===== ANIMATIONS ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content-section {
    animation: fadeInUp var(--transition-slow) ease-out;
}

/* ===== UTILITY CLASSES ===== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ===== PRINT STYLES ===== */
@media print {
    .hero-header,
    .main-nav,
    .site-footer {
        display: none;
    }
    
    .content-section {
        box-shadow: none;
        border: 1px solid var(--gray-300);
        break-inside: avoid;
    }
    
    .talk-abstract {
        max-height: none !important;
        opacity: 1 !important;
    }
}