/* =============================================================================
   Scrum Day London - Main Stylesheet
   A modern, professional Agile conference website
   ============================================================================= */

/* CSS Variables */
:root {
    /* Brand Colors */
    --color-primary: #0F2F5C;
    --color-primary-dark: #0A1F3F;
    --color-primary-light: #1A4A7C;
    --color-accent: #4FC3E8;
    --color-pink: #ec4899;
    --color-pink-dark: #d03682;
    
    /* Neutral Colors */
    --color-white: #FFFFFF;
    --color-light-gray: #F5F7FA;
    --color-medium-gray: #E1E8ED;
    --color-dark-gray: #5A6C7D;
    --color-text: var(--color-primary);
    --color-text-light: #6B7C8D;
    --color-pink: #ec4899;
    --color-pink-dark: #d03682;
    
    /* Typography */
    --font-primary: 'Manrope', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'Space Mono', 'Courier New', monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 5rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(15, 47, 92, 0.08);
    --shadow-md: 0 4px 16px rgba(15, 47, 92, 0.12);
    --shadow-lg: 0 8px 32px rgba(15, 47, 92, 0.16);
    --shadow-xl: 0 16px 48px rgba(15, 47, 92, 0.2);
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    line-height: 1.7;
    background-color: var(--color-white);
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all var(--transition-fast);
}

ul {
    list-style: none;
}

button {
    font-family: var(--font-primary);
    cursor: pointer;
    border: none;
    background: none;
}

/* Container */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Navigation */
.main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--color-white);
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.nav-brand a {
    display: flex;
    flex-direction: column;
    line-height: 1.1;
}

.brand-text {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--color-pink);
    letter-spacing: -0.02em;
}

.brand-location {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-primary);
    letter-spacing: 0.15em;
    font-weight: 700;
}

.brand-logo {
    height: 56px;
    width: auto;
    display: block;
}

@media (max-width: 480px) {
    .brand-logo {
        height: 42px;
    }
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 28px;
    height: 28px;
}

.nav-toggle span {
    display: block;
    width: 100%;
    height: 3px;
    background: var(--color-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

.nav-menu {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.nav-menu li a {
    padding: 0.5rem 1rem;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-text);
    border-radius: 6px;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-menu li a:hover,
.nav-menu li a.active {
    color: var(--color-primary);
    background: var(--color-light-gray);
}

.nav-menu li a.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 1rem;
    right: 1rem;
    height: 2px;
    background: var(--color-accent);
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding-top: 80px;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        linear-gradient(135deg, rgba(15, 47, 92, 0.75) 0%, rgba(26, 74, 124, 0.75) 100%),
        url("../images/Sdl_banner_001.jpeg");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 1;
}

.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(79, 195, 232, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(79, 195, 232, 0.1) 0%, transparent 50%);
}

.hero-background::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        repeating-linear-gradient(0deg, transparent, transparent 2px, rgba(255, 255, 255, 0.03) 2px, rgba(255, 255, 255, 0.03) 4px);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: var(--color-white);
    animation: fadeInUp 0.8s ease;
}

.hero-date {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    letter-spacing: 0.2em;
    color: var(--color-accent-light);
    margin-bottom: var(--spacing-sm);
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-title {
    margin-bottom: var(--spacing-sm);
}

.title-main {
    display: block;
    font-size: clamp(3rem, 10vw, 7rem);
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 0.9;
    animation: fadeInUp 0.8s ease 0.3s backwards;
}

.title-sub {
    display: block;
    font-size: clamp(1.5rem, 5vw, 3.5rem);
    font-weight: 300;
    letter-spacing: 0.3em;
    margin-top: 0.5rem;
    color: var(--color-accent-light);
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.hero-tagline {
    font-size: clamp(1.1rem, 2.5vw, 1.5rem);
    font-weight: 400;
    margin-bottom: var(--spacing-lg);
    opacity: 0.95;
    animation: fadeInUp 0.8s ease 0.5s backwards;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.6s backwards;
}

.hero-scroll {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--color-white);
    opacity: 0.7;
    animation: fadeIn 1s ease 1s backwards;
}

.hero-scroll span {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    font-family: var(--font-mono);
}

.scroll-indicator {
    width: 2px;
    height: 40px;
    background: linear-gradient(to bottom, var(--color-accent-light), transparent);
    animation: scrollBounce 2s infinite;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 1rem 2rem;
    font-weight: 600;
    font-size: 1rem;
    border-radius: 8px;
    transition: all var(--transition-normal);
    text-align: center;
    border: 2px solid transparent;
}

.btn-primary {
    background: #E84A6A;
    color: var(--color-white);
    box-shadow: 0 4px 12px rgba(232, 74, 106, 0.3);
}

.btn-primary:hover {
    background: #c93a58;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(232, 74, 106, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--color-white);
    border-color: #E84A6A;
}

.btn-secondary:hover {
    background: #E84A6A;
    color: var(--color-white);
}

.btn-tertiary {
    background: #E84A6A;
    color: var(--color-white);
    backdrop-filter: blur(10px);
}

.btn-tertiary:hover {
    background: #c93a58;
}

.btn-ticket {
    width: 100%;
    background: #E84A6A;
    color: var(--color-white);
}

.btn-ticket:hover {
    background: #c93a58;
    transform: translateY(-2px);
}

.btn-ticket.btn-featured {
    background: #E84A6A;
}

.btn-ticket.btn-featured:hover {
    background: #c93a58;
}

/* Sections */
section {
    padding: var(--spacing-xl) 0;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.section-title.centered {
    text-align: center;
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-light);
    text-align: center;
    margin-bottom: var(--spacing-lg);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.section-cta {
    text-align: center;
    margin-top: var(--spacing-lg);
}

/* Overview Section */
.overview {
    background: var(--color-white);
}

.overview-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.overview-text {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

.overview-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.stat {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--color-light-gray);
    border-radius: 12px;
    transition: all var(--transition-normal);
}

.stat:hover {
    background: var(--color-primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.stat:hover .stat-number,
.stat:hover .stat-label {
    color: var(--color-white);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: 0.5rem;
    transition: color var(--transition-normal);
}

.stat-label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-dark-gray);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    transition: color var(--transition-normal);
}

.overview-visual {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.visual-card {
    background: var(--color-light-gray);
    padding: var(--spacing-md);
    border-radius: 12px;
    border-left: 4px solid var(--color-accent);
    transition: all var(--transition-normal);
}

.visual-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.visual-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.visual-card p {
    color: var(--color-text-light);
    line-height: 1.6;
}

/* Featured Speakers Section */
.featured-speakers {
    background: var(--color-light-gray);
}

.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.speaker-card {
    background: var(--color-white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    animation: fadeInUp 0.6s ease backwards;
}

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

.speaker-image {
    position: relative;
    width: 100%;
    aspect-ratio: 1;
    overflow: hidden;
}

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

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

.speaker-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to top, rgba(15, 47, 92, 0.9), transparent);
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: var(--spacing-md);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

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

.view-profile {
    color: var(--color-white);
    font-weight: 600;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.speaker-card h3,
.speaker-card p {
    padding: 0 var(--spacing-md);
}

.speaker-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-top: var(--spacing-md);
    margin-bottom: 0.25rem;
}

.speaker-role {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: 0.25rem;
}

.speaker-company {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}

/* Schedule Section */
.schedule-preview {
    background: var(--color-white);
}

.schedule-tabs {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.tab-btn {
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
    background: var(--color-light-gray);
    border-radius: 8px;
    transition: all var(--transition-fast);
}

.tab-btn.active {
    background: #E84A6A;
    color: var(--color-white);
}

.tab-btn:hover {
    background: #c93a58;
    color: var(--color-white);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.4s ease;
}

.schedule-item {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--color-light-gray);
    border-radius: 12px;
    margin-bottom: var(--spacing-md);
    border-left: 4px solid var(--color-accent);
    transition: all var(--transition-normal);
}

.schedule-item:hover {
    background: var(--color-white);
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.schedule-time {
    font-family: var(--font-mono);
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-primary);
}

.schedule-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: 0.75rem;
}

.schedule-meta {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
    flex-wrap: wrap;
}

.schedule-speaker {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.95rem;
    color: var(--color-text);
}

.schedule-speaker img {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    object-fit: cover;
}

.schedule-room {
    font-size: 0.9rem;
    color: var(--color-text-light);
    padding: 0.375rem 0.875rem;
    background: var(--color-white);
    border-radius: 6px;
    font-weight: 500;
}

/* Tickets Section */
.tickets-section {
    background: var(--color-light-gray);
}

.tickets-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    max-width: 1100px;
    margin: 0 auto;
}

.ticket-card {
    background: var(--color-white);
    border-radius: 16px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    position: relative;
    display: flex;
    flex-direction: column;
}

.ticket-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.ticket-card.featured {
    border: 3px solid var(--color-accent);
    transform: scale(1.05);
}

.ticket-card.featured:hover {
    transform: scale(1.05) translateY(-8px);
}

.ticket-badge {
    position: absolute;
    top: -12px;
    right: var(--spacing-md);
    background: var(--color-accent);
    color: var(--color-white);
    padding: 0.375rem 1rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.1em;
}

.ticket-header {
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-light-gray);
}

.ticket-name {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.ticket-price {
    display: flex;
    flex-direction: column;
}

.price-amount {
    font-size: 3rem;
    font-weight: 800;
    color: var(--color-accent);
    line-height: 1;
}

.price-period {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-top: 0.25rem;
}

.ticket-features {
    flex-grow: 1;
    margin-bottom: var(--spacing-md);
}

.ticket-features li {
    padding: 0.75rem 0;
    color: var(--color-text);
    border-bottom: 1px solid var(--color-light-gray);
    font-size: 0.95rem;
}

.ticket-features li:last-child {
    border-bottom: none;
}

.ticket-note {
    text-align: center;
    font-size: 0.85rem;
    color: var(--color-text-light);
    margin-top: var(--spacing-sm);
    font-style: italic;
}

/* Sponsors Section */
.sponsors-section {
    background: var(--color-white);
}

.sponsors-tier {
    margin-bottom: var(--spacing-xl);
}

.tier-title {
    text-align: center;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.sponsors-logos {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.sponsor-logo {
    padding: var(--spacing-md);
    transition: all var(--transition-normal);
}

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

.logo-placeholder {
    font-family: var(--font-mono);
    font-weight: 700;
    letter-spacing: 0.1em;
    padding: var(--spacing-md) var(--spacing-lg);
    border: 2px solid var(--color-medium-gray);
    border-radius: 8px;
    color: var(--color-dark-gray);
    transition: all var(--transition-normal);
}

.sponsors-logos.platinum .logo-placeholder {
    font-size: 1.5rem;
}

.sponsors-logos.gold .logo-placeholder {
    font-size: 1.25rem;
}

.sponsors-logos.silver .logo-placeholder {
    font-size: 1rem;
}

.sponsor-logo:hover .logo-placeholder {
    border-color: var(--color-accent);
    color: var(--color-accent);
    background: var(--color-light-gray);
}

/* FAQ Section */
.faq-section {
    background: var(--color-light-gray);
}

.faq-grid {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: var(--color-white);
    border-radius: 12px;
    margin-bottom: var(--spacing-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-primary);
    text-align: left;
    transition: all var(--transition-fast);
}

.faq-question:hover {
    background: var(--color-light-gray);
}

.faq-icon {
    font-size: 1.5rem;
    color: var(--color-pink);
    transition: transform var(--transition-fast);
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 var(--spacing-lg) var(--spacing-md);
    color: var(--color-text);
    line-height: 1.7;
}

/* Footer */
.main-footer {
    background: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-title {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
}

.footer-text {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

.footer-social {
    display: flex;
    gap: var(--spacing-sm);
}

.footer-social a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    transition: all var(--transition-fast);
}

.footer-social a:hover {
    background: var(--color-accent);
    transform: translateY(-2px);
}

.footer-heading {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: color var(--transition-fast);
}

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

.footer-contact li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: var(--spacing-sm);
    color: rgba(255, 255, 255, 0.8);
}

.footer-contact svg {
    flex-shrink: 0;
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer-legal {
    display: flex;
    gap: var(--spacing-md);
}

.footer-legal a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

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

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

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

@keyframes scrollBounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(10px);
    }
}

/* Page Header */
.page-header {
    padding: calc(80px + var(--spacing-xl)) 0 var(--spacing-xl);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    color: var(--color-white);
    text-align: center;
}

.page-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    line-height: 1.1;
}

.page-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
}

/* About Page Styles */
.about-mission {
    background: var(--color-white);
}

.content-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-xl);
}

.content-main p {
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.lead-text {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.info-box {
    background: var(--color-light-gray);
    padding: var(--spacing-lg);
    border-radius: 12px;
    position: sticky;
    top: 100px;
}

.info-box h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.fact-list {
    list-style: none;
}

.fact-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--color-medium-gray);
    font-size: 0.95rem;
}

.fact-list li:last-child {
    border-bottom: none;
}

.fact-list strong {
    color: var(--color-primary);
    font-weight: 600;
}

/* Timeline */
.about-history {
    background: var(--color-light-gray);
}

.timeline {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 80px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--color-accent);
}

.timeline-item {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.timeline-year {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-pink);
    text-align: right;
    padding-top: 0.5rem;
}

.timeline-item::after {
    content: '';
    position: absolute;
    left: 73px;
    top: 10px;
    width: 16px;
    height: 16px;
    background: var(--color-pink-dark);
    border-radius: 50%;
    border: 3px solid var(--color-white);
    box-shadow: 0 0 0 3px var(--color-pink-dark);
}

.timeline-content {
    background: var(--color-white);
    padding: var(--spacing-md);
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
}

.timeline-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: 0.75rem;
}

.timeline-content p {
    color: var(--color-primary-dark);
    line-height: 1.7;
}

/* Theme Section */
.about-theme {
    background: var(--color-white);
}

.theme-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.theme-card {
    background: var(--color-light-gray);
    padding: var(--spacing-lg);
    border-radius: 12px;
    text-align: center;
    transition: all var(--transition-normal);
}

.theme-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    background: var(--color-white);
}

.theme-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-pink);
}

.theme-icon i {
    font-size: inherit;
    color: inherit;
    display: inline-block;
    line-height: 1;
}

.theme-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.theme-card p {
    color: var(--color-text-light);
    line-height: 1.6;
}

/* Values Section */
.about-values {
    background: var(--color-light-gray);
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.value-item {
    background: var(--color-white);
    padding: var(--spacing-lg);
    border-radius: 12px;
    border-top: 4px solid var(--color-accent);
    text-align: center;
    transition: all var(--transition-normal);
}

.value-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.value-item h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.value-item p {
    color: var(--color-text-light);
    line-height: 1.6;
}

/* CTA Section */
.about-cta {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    color: var(--color-white);
    text-align: center;
}

.cta-content h2 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.cta-content p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    opacity: 0.95;
}

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

/* Nav menu responsive behavior (matches Bootstrap's lg collapse breakpoint) */
@media (max-width: 991.98px) {
    .navbar-collapse {
        margin-top: var(--spacing-sm);
        border-top: 1px solid var(--color-medium-gray);
        padding-top: var(--spacing-sm);
    }

    .nav-menu {
        flex-direction: column;
        align-items: stretch;
        gap: 0.25rem;
        width: 100%;
    }

    .nav-menu li a {
        display: block;
        width: 100%;
        text-align: center;
    }
}

/* Responsive Design */
@media (max-width: 1024px) {
    .overview-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .overview-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .schedule-item {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }
    
    .tickets-grid {
        grid-template-columns: 1fr;
    }
    
    .ticket-card.featured {
        transform: scale(1);
    }
    
    .ticket-card.featured:hover {
        transform: scale(1) translateY(-8px);
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-xl: 3rem;
    }
    
    .hero-cta {
        flex-direction: column;
        width: 100%;
        max-width: 300px;
        margin: 0 auto;
    }
    
    .btn {
        width: 100%;
    }
    
    .overview-stats {
        grid-template-columns: 1fr;
    }
    
    .schedule-tabs {
        flex-direction: column;
    }
    
    .tab-btn {
        width: 100%;
    }
}

    .content-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline::before {
        left: 60px;
    }
    
    .timeline-item {
        grid-template-columns: 80px 1fr;
    }
    
    .timeline-item::after {
        left: 53px;
    }


/* Speakers Page Styles */
.speakers-full {
    background: var(--color-white);
}

.speakers-intro {
    max-width: 800px;
    margin: 0 auto var(--spacing-xl);
    text-align: center;
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text);
}

.speakers-grid-full {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.speaker-card-full {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: var(--spacing-lg);
    background: var(--color-light-gray);
    border-radius: 16px;
    overflow: hidden;
    padding: var(--spacing-lg);
    transition: all var(--transition-normal);
}

.speaker-card-full:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-lg);
    background: var(--color-white);
}

.speaker-card-full .speaker-image {
    width: 100%;
    aspect-ratio: 1;
    border-radius: 12px;
    overflow: hidden;
}

.speaker-card-full .speaker-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.speaker-details {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.speaker-bio {
    color: var(--color-text);
    line-height: 1.7;
    flex-grow: 1;
}

.speaker-topics {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.topic {
    display: inline-block;
    padding: 0.375rem 0.875rem;
    background: var(--color-primary);
    color: var(--color-white);
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.speakers-cta {
    text-align: center;
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 16px;
    color: var(--color-white);
}

.speakers-cta h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.speakers-cta p {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.95;
}

/* Form Styles */
.form-section {
    background: var(--color-white);
}

.form-container {
    max-width: 700px;
    margin: 0 auto;
    background: var(--color-light-gray);
    padding: var(--spacing-xl);
    border-radius: 16px;
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: 0.875rem 1rem;
    font-family: var(--font-primary);
    font-size: 1rem;
    border: 2px solid var(--color-medium-gray);
    border-radius: 8px;
    background: var(--color-white);
    transition: all var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(79, 195, 232, 0.1);
}

.form-textarea {
    min-height: 150px;
    resize: vertical;
}

.form-input.error,
.form-textarea.error,
.form-select.error {
    border-color: #e74c3c;
}

.form-success {
    background: #27ae60;
    color: white;
    padding: 1rem;
    border-radius: 8px;
    margin-top: 1rem;
    text-align: center;
}

.form-error {
    background: #e74c3c;
    color: white;
    padding: 1rem;
    border-radius: 8px;
    margin-top: 1rem;
    text-align: center;
}

@media (max-width: 768px) {
    .speaker-card-full {
        grid-template-columns: 1fr;
    }

    .speaker-card-full .speaker-image {
        max-width: 300px;
        margin: 0 auto;
    }

    .timeline-year {
        font-size: 1.25rem;
    }
}

/* Speaker Papers Page */
.papers-full {
    background: var(--color-white);
}

.papers-intro {
    max-width: 800px;
    margin: 0 auto var(--spacing-lg);
    text-align: center;
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text);
}

.papers-theme-box {
    max-width: 900px;
    margin: 0 auto var(--spacing-xl);
    background: var(--color-light-gray);
    border-left: 4px solid var(--color-accent);
    border-radius: 12px;
    padding: var(--spacing-lg);
    text-align: center;
}

.papers-theme-label {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    letter-spacing: 0.15em;
    color: var(--color-accent);
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 0.5rem;
}

.papers-theme-box h2 {
    color: var(--color-primary);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.papers-theme-box p {
    color: var(--color-text-light);
}

.papers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.paper-card {
    background: var(--color-light-gray);
    border-radius: 16px;
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    transition: all var(--transition-normal);
}

.paper-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    background: var(--color-white);
}

.paper-speaker {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.paper-avatar {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
}

.paper-name {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-primary);
}

.paper-role {
    font-size: 0.85rem;
    color: var(--color-text-light);
}

.paper-topic {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--color-primary-dark);
    line-height: 1.5;
    flex-grow: 1;
}

.paper-read-btn {
    align-self: flex-start;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

/* PDF Viewer Modal */
.pdf-modal {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
}

.pdf-modal.active {
    display: flex;
}

.pdf-modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(10, 31, 63, 0.75);
}

.pdf-modal-content {
    position: relative;
    background: var(--color-white);
    border-radius: 16px;
    width: min(900px, 100%);
    height: min(85vh, 1000px);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    animation: fadeInUp 0.3s ease;
}

.pdf-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-primary);
    color: var(--color-white);
}

.pdf-modal-header h3 {
    font-size: 1.1rem;
    font-weight: 700;
}

.pdf-modal-close {
    color: var(--color-white);
    font-size: 1.75rem;
    line-height: 1;
    padding: 0.25rem 0.5rem;
}

.pdf-modal-close:hover {
    color: var(--color-accent);
}

.pdf-modal-body {
    flex-grow: 1;
    background: var(--color-medium-gray);
}

.pdf-modal-body iframe {
    width: 100%;
    height: 100%;
    border: none;
}

@media (max-width: 768px) {
    .papers-grid {
        grid-template-columns: 1fr;
    }

    .pdf-modal-content {
        height: 90vh;
    }

    .pdf-modal-header h3 {
        font-size: 0.95rem;
    }
}