/* ============================================
   CSS CUSTOM PROPERTIES (Design System)
   ============================================ */
:root {
    /* Color Palette - Light Theme with Cool Colors */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --light-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    
    /* Solid Colors - Light Theme */
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #4facfe;
    --text-primary: #2d3748;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --bg-light: #ffffff;
    --bg-gray: #f7fafc;
    --bg-card: #ffffff;
    --bg-card-hover: #f7fafc;
    --border-color: #e2e8f0;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
    --radius-xl: 2rem;
    
    /* Shadows - Light Theme */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.2);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-gray);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: clamp(1.25rem, 2.5vw, 1.75rem); }

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition-base);
}

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

/* ============================================
   UTILITY CLASSES
   ============================================ */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.text-center {
    text-align: center;
}

.gradient-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: inline-block;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    display: inline-block;
    padding: 1rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    border: none;
    transition: all var(--transition-base);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.1);
    transition: var(--transition-base);
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem var(--spacing-md);
    gap: 2rem;
}

/* Left Logo */
.nav-brand {
    flex-shrink: 0;
    display: flex;
    align-items: center;
}

.nav-logo {
    height: 90px;
    width: auto;
    object-fit: contain;
    transition: var(--transition-base);
}

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

/* Center Navigation Menu */
.nav-menu {
    display: flex;
    list-style: none;
    gap: 0.5rem;
    align-items: center;
    justify-content: center;
    flex-wrap: nowrap;
    flex: 1;
    white-space: nowrap;
}

.nav-link {
    color: var(--text-secondary);
    font-size: 1.05rem;
    font-weight: 600;
    padding: 0.6rem 1.25rem;
    border-radius: var(--radius-sm);
    transition: var(--transition-base);
    position: relative;
    display: flex;
    align-items: center;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--primary-gradient);
    transition: var(--transition-base);
}

.nav-link:hover {
    color: var(--text-primary);
    background: rgba(139, 92, 246, 0.05);
}

.nav-link:hover::after {
    width: 80%;
}

/* Right Logo */
.nav-logo-container {
    flex-shrink: 0;
    display: flex;
    align-items: center;
}

.nav-logo-right {
    height: 90px;
    width: 90px;
    object-fit: cover;
    border-radius: 50%;
    transition: var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.nav-logo-right:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

/* Mobile Toggle Button */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 0.4rem;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition-base);
}


/* ============================================
   HERO SECTION
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding-top: 140px; /* Adjusted for navbar with 90px logos */
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--light-gradient);
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    z-index: -1;
}

/* Page-specific hero backgrounds using Unsplash images */

/* Home page - DNA/Cancer Research */
#home .hero-background {
    background-image: 
        linear-gradient(rgba(10, 10, 15, 0.7), rgba(10, 10, 15, 0.8)),
        url('https://images.unsplash.com/photo-1576086213369-97a306d36557?w=1920&q=80');
}

/* Speakers page - Conference/Presentation */
body:has([href="speakers.html"].nav-link) .hero[style*="min-height: 50vh"] .hero-background,
.speakers-page .hero-background {
    background-image: 
        linear-gradient(rgba(10, 10, 15, 0.75), rgba(10, 10, 15, 0.85)),
        url('https://images.unsplash.com/photo-1540575467063-178a50c2df87?w=1920&q=80');
}

/* Organizers page - Cancer cells background */
.organizers-page .hero-background {
    background-image: 
        linear-gradient(rgba(10, 10, 15, 0.7), rgba(10, 10, 15, 0.8)),
        url('/assets/images/cancer_cells_bg.png?v=2');
}

/* Program page - Cancer cells background */
.program-page .hero-background {
    background-image: 
        linear-gradient(rgba(10, 10, 15, 0.75), rgba(10, 10, 15, 0.85)),
        url('/assets/images/cancer_cells_bg.png?v=2');
}

/* Venue page - Cancer cells background */
.venue-page .hero-background {
    background-image: 
        linear-gradient(rgba(10, 10, 15, 0.7), rgba(10, 10, 15, 0.8)),
        url('/assets/images/cancer_cells_bg.png?v=2');
}

/* Instructions page - Cancer cells background */
.instructions-page .hero-background {
    background-image: 
        linear-gradient(rgba(10, 10, 15, 0.75), rgba(10, 10, 15, 0.85)),
        url('/assets/images/cancer_cells_bg.png?v=2');
}

/* Default for other pages */
body:has(.hero[style*="min-height: 50vh"]) .hero-background {
    background-image: 
        linear-gradient(rgba(10, 10, 15, 0.75), rgba(10, 10, 15, 0.85)),
        url('https://images.unsplash.com/photo-1532187863486-abf9dbad1b69?w=1920&q=80');
}

.hero-background::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(102, 126, 234, 0.15) 0%, transparent 70%);
    animation: pulse 8s ease-in-out infinite;
}

.hero-background::after {
    content: '';
    position: absolute;
    bottom: -50%;
    left: -50%;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(118, 75, 162, 0.15) 0%, transparent 70%);
    animation: pulse 8s ease-in-out infinite reverse;
}

/* Add subtle DNA helix pattern */
.hero::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        repeating-linear-gradient(
            45deg,
            transparent,
            transparent 100px,
            rgba(102, 126, 234, 0.02) 100px,
            rgba(102, 126, 234, 0.02) 102px
        ),
        repeating-linear-gradient(
            -45deg,
            transparent,
            transparent 100px,
            rgba(118, 75, 162, 0.02) 100px,
            rgba(118, 75, 162, 0.02) 102px
        );
    z-index: 0;
    pointer-events: none;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.2); opacity: 0.8; }
}

.hero-content {
    text-align: center;
    z-index: 1;
    padding: var(--spacing-2xl) 0;
}

.hero-title {
    margin-bottom: var(--spacing-md);
    font-weight: 800;
    color: #ffffff;
    line-height: 1.3;
}

.hero-workshop-title {
    font-size: 0.75em;
    display: block;
    margin-top: 0.5rem;
}

.hero-subtitle {
    font-size: clamp(1.25rem, 2.5vw, 1.75rem);
    color: #ffffff;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
}

.hero-date {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
}

.hero-organizer {
    font-size: 1.1rem;
    color: #f7fafc;
    margin-bottom: var(--spacing-sm);
}

.hero-partnership {
    font-size: 1rem;
    color: #e2e8f0;
    margin-bottom: var(--spacing-xl);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

.mouse {
    width: 30px;
    height: 50px;
    border: 2px solid var(--text-secondary);
    border-radius: 20px;
    display: flex;
    justify-content: center;
    padding-top: 8px;
}

.wheel {
    width: 4px;
    height: 10px;
    background: var(--text-secondary);
    border-radius: 2px;
    animation: scroll 1.5s infinite;
}

@keyframes scroll {
    0% { opacity: 1; transform: translateY(0); }
    100% { opacity: 0; transform: translateY(15px); }
}

/* Fade-in Animations */
.animate-fade-in {
    animation: fadeIn 1s ease-out;
}

.animate-fade-in-delay-1 {
    animation: fadeIn 1s ease-out 0.2s both;
}

.animate-fade-in-delay-2 {
    animation: fadeIn 1s ease-out 0.4s both;
}

.animate-fade-in-delay-3 {
    animation: fadeIn 1s ease-out 0.6s both;
}

.animate-fade-in-delay-4 {
    animation: fadeIn 1s ease-out 0.8s both;
}

.animate-fade-in-delay-5 {
    animation: fadeIn 1s ease-out 1s both;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   SECTION STYLES
   ============================================ */
section {
    padding: var(--spacing-3xl) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-md);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: var(--primary-gradient);
    margin: var(--spacing-md) auto;
    border-radius: 2px;
}

.section-description {
    text-align: center;
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto var(--spacing-xl);
}

/* ============================================
   THEME SECTION
   ============================================ */
.theme-section {
    background: var(--bg-light);
    position: relative;
}

/* Add subtle molecular pattern */
.theme-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.03) 0%, transparent 50%),
                      radial-gradient(circle at 80% 80%, rgba(118, 75, 162, 0.03) 0%, transparent 50%),
                      radial-gradient(circle at 40% 20%, rgba(79, 172, 254, 0.03) 0%, transparent 50%);
    z-index: 0;
    pointer-events: none;
}

.theme-section > .container {
    position: relative;
    z-index: 1;
}

.theme-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.theme-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.theme-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transition: var(--transition-base);
}

.theme-card:hover {
    transform: translateY(-10px);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-glow);
}

.theme-card:hover::before {
    transform: scaleX(1);
}

.theme-image {
    width: 100%;
    height: 250px;
    margin-bottom: var(--spacing-md);
    border-radius: var(--radius-md);
    overflow: hidden;
    position: relative;
}

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

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

.theme-card h3 {
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.theme-card p {
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ============================================
   FOCUS SECTION
   ============================================ */
.focus-section {
    background: var(--bg-gray);
    position: relative;
}

/* Add subtle grid pattern */
.focus-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(rgba(102, 126, 234, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(102, 126, 234, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    z-index: 0;
    pointer-events: none;
}

.focus-section > .container {
    position: relative;
    z-index: 1;
}

.focus-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.focus-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.focus-item:hover {
    transform: translateX(10px);
    background: var(--bg-card-hover);
    border-color: rgba(102, 126, 234, 0.3);
}

.focus-number {
    font-size: 2rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    flex-shrink: 0;
    font-family: var(--font-heading);
}

.focus-item p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin: 0;
}

/* ============================================
   INSTITUTES & SPONSORS SECTION
   ============================================ */
.institutes-section {
    background: var(--bg-light);
    position: relative;
}

.institutes-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: radial-gradient(circle at 50% 50%, rgba(102, 126, 234, 0.02) 0%, transparent 70%);
    z-index: 0;
    pointer-events: none;
}

.institutes-section > .container {
    position: relative;
    z-index: 1;
}

.institutes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.institute-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 180px;
    transition: var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.institute-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.institute-card img {
    max-width: 100%;
    max-height: 100px;
    object-fit: contain;
    filter: brightness(1.1);
    transition: var(--transition-base);
    margin-bottom: var(--spacing-sm);
}

.institute-card:hover img {
    filter: brightness(1.2);
    transform: scale(1.05);
}

.institute-name {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-align: center;
    margin-top: var(--spacing-sm);
    font-weight: 500;
    line-height: 1.4;
}

/* BD Partnership Section */
.bd-partnership-section {
    margin-top: var(--spacing-3xl);
    padding-top: var(--spacing-xl);
    border-top: 2px solid var(--border-color);
    text-align: center;
}

.bd-partnership-title {
    font-size: clamp(1.75rem, 3vw, 2.5rem);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-weight: 700;
}

.bd-partnership-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.bd-logo-container {
    display: flex;
    justify-content: center;
    align-items: center;
}

.bd-logo {
    max-width: 300px;
    max-height: 150px;
    object-fit: contain;
    transition: var(--transition-base);
}

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

/* ============================================
   SPEAKERS SECTION
   ============================================ */
.speakers-section {
    background: var(--bg-gray);
}

.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.speaker-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.speaker-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(102, 126, 234, 0.1), transparent);
    transition: var(--transition-slow);
}

.speaker-card:hover::before {
    left: 100%;
}

.speaker-card:hover {
    transform: translateY(-8px);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-lg);
    border-color: rgba(102, 126, 234, 0.3);
}

.speaker-avatar {
    width: 120px;
    height: 120px;
    margin: 0 auto var(--spacing-md);
    border-radius: 50%;
    background: var(--primary-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    border: 3px solid rgba(255, 255, 255, 0.1);
    transition: var(--transition-base);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.speaker-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.speaker-card:hover .speaker-avatar {
    border-color: rgba(102, 126, 234, 0.5);
    box-shadow: 0 6px 25px rgba(102, 126, 234, 0.4);
    transform: scale(1.05);
}

.avatar-placeholder {
    font-size: 2rem;
    font-weight: 700;
    color: white;
}

.speaker-card h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.speaker-title {
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.speaker-affiliation {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ============================================
   REGISTRATION & CONTACT SECTION
   ============================================ */
.registration-section {
    background: linear-gradient(180deg, rgba(15, 12, 41, 0.8) 0%, var(--bg-dark) 100%);
}

.registration-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.registration-card,
.contact-card {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    transition: all var(--transition-base);
}

.registration-card:hover,
.contact-card:hover {
    transform: translateY(-5px);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-lg);
}

.registration-card h2,
.contact-card h2 {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
}

.contact-info {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--primary-color);
}

.contact-info p {
    margin-bottom: var(--spacing-xs);
}

.contact-info strong {
    color: var(--text-primary);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background: var(--bg-light);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-2xl) 0 var(--spacing-md);
}

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

.footer-section h3,
.footer-section h4 {
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.footer-section p {
    color: var(--text-muted);
    margin-bottom: var(--spacing-xs);
}

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

.footer-section ul li {
    margin-bottom: var(--spacing-xs);
}

.footer-section ul li a {
    color: var(--text-secondary);
    transition: var(--transition-base);
}

.footer-section ul li a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
    /* Adjust navbar for mobile */
    .nav-container {
        padding: 0.75rem var(--spacing-md);
        gap: 1rem;
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: space-between;
    }
    
    /* Logos side by side on mobile */
    .nav-brand {
        order: 0;
        flex: 0 0 auto;
    }
    
    .nav-logo-container {
        order: 2;
        flex: 0 0 auto;
    }
    
    /* Smaller logos on mobile */
    .nav-logo {
        height: 60px;
        width: auto;
    }
    
    .nav-logo-right {
        height: 60px;
        width: 60px;
    }
    
    /* Position nav toggle between logos */
    .nav-toggle {
        display: flex;
        order: 1;
        position: relative;
        top: auto;
        right: auto;
        z-index: 1001;
        margin-left: auto;
    }
    
    /* Mobile menu */
    .nav-menu {
        position: fixed;
        top: 100px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 100px);
        background: rgba(10, 10, 15, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: flex-start;
        padding: var(--spacing-xl);
        transition: var(--transition-base);
        gap: var(--spacing-md);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
    }
    
    .theme-grid,
    .focus-grid,
    .speakers-grid {
        grid-template-columns: 1fr;
    }
    
    .registration-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-3xl: 3rem;
        --spacing-2xl: 2rem;
    }
    
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .nav-brand h2 {
        font-size: 1rem;
    }
}