/* ===================================
   CSS Custom Properties (Variables)
   =================================== */
:root {
    /* Color Scheme - Based on INS 2026 Branding */
    --primary-dark: #0B4F6C;
    --primary: #1565A0;
    --primary-light: #1BA098;
    --secondary: #20B2AA;
    --accent: #FFB300;
    --accent-light: #FFC947;

    /* Neutral Colors */
    --white: #FFFFFF;
    --light-gray: #F5F7FA;
    --gray: #E0E7EF;
    --dark-gray: #6B7280;
    --text-dark: #1F2937;
    --text-light: #6B7280;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #0B4F6C 0%, #1565A0 50%, #1BA098 100%);
    --gradient-secondary: linear-gradient(135deg, #1BA098 0%, #20B2AA 100%);
    --gradient-accent: linear-gradient(135deg, #FFB300 0%, #FFC947 100%);
    --gradient-overlay: linear-gradient(135deg, rgba(11, 79, 108, 0.95) 0%, rgba(27, 160, 152, 0.85) 100%);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Poppins', 'Inter', 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: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;

    /* 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);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===================================
   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(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
    background-color: var(--white);
}

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

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

ul {
    list-style: none;
}

/* ===================================
   Utility Classes
   =================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

.section-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--gradient-accent);
    color: var(--white);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-md);
}

.section-title {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-dark);
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* Button Styles */
.btn-primary,
.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-base);
    border: none;
    text-align: center;
    justify-content: center;
}

.btn-primary {
    background: var(--gradient-accent);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

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

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

.btn-large {
    padding: 1.125rem 2.5rem;
    font-size: 1.125rem;
}

/* Animation Classes */
.fade-in {
    animation: fadeIn var(--transition-slow) ease-out;
}

.fade-in-delay {
    animation: fadeIn var(--transition-slow) ease-out 0.3s backwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===================================
   Navigation
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: transparent;
    padding: var(--spacing-md) 0;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-text {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--white);
    transition: color var(--transition-base);
}

.logo-image {
    height: 50px;
    width: auto;
    transition: all var(--transition-base);
}

.navbar.scrolled .logo-image {
    height: 45px;
}

.navbar.scrolled .logo-text {
    color: var(--primary-dark);
}

.logo-text .highlight {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-link {
    color: var(--white);
    font-weight: 500;
    font-size: 0.9375rem;
    position: relative;
    transition: all var(--transition-base);
}

.navbar.scrolled .nav-link {
    color: var(--text-dark);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-btn {
    background: var(--gradient-accent);
    color: var(--white) !important;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
}

.nav-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--white);
    font-size: 1.5rem;
    cursor: pointer;
}

.navbar.scrolled .mobile-menu-toggle {
    color: var(--primary-dark);
}

.mobile-menu-close {
    display: none;
    /* Hidden on desktop */
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: var(--spacing-3xl) 0;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    /* background: var(--gradient-primary);*/
    background-image: url('../assets/header-bg.jpg');
    background-repeat: no-repeat;
    background-size: cover;
    z-index: -1;
}

.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 20% 50%, rgba(255, 179, 0, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(32, 178, 170, 0.15) 0%, transparent 50%);
    animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        opacity: 0.8;
    }

    50% {
        opacity: 1;
    }
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

.hero-text {
    color: var(--white);
}

.hero-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.hero-title {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 300;
    font-style: italic;
    margin-bottom: var(--spacing-xl);
    opacity: 0.95;
}

.hero-subtitle i {
    font-size: 0.75rem;
    opacity: 0.7;
    margin: 0 var(--spacing-xs);
}

.hero-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    align-items: center;
}

.detail-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 1.125rem;
}

.detail-item i {
    font-size: 1.5rem;
    color: var(--accent);
}

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

/* Countdown Timer */
.countdown-container {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
    width: 100%;
}

.countdown-title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    color: var(--white);
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.countdown {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
}

.countdown-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(5px);
}

.countdown-value {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--accent);
    line-height: 1;
}

.countdown-label {
    font-size: 0.875rem;
    color: var(--white);
    margin-top: var(--spacing-xs);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.hero-wave {
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
    width: 100%;
}

.hero-wave svg {
    display: block;
    width: 100%;
    height: auto;
}

/* ===================================
   About Section
   =================================== */
.about {
    padding: var(--spacing-3xl) 0;
    background: var(--white);
}

.about-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.about-text h3 {
    font-family: var(--font-heading);
    font-size: 2rem;
    color: var(--primary-dark);
    margin-bottom: var(--spacing-md);
}

.about-text p {
    font-size: 1.0625rem;
    line-height: 1.8;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.about-text strong {
    color: var(--primary);
    font-weight: 600;
}

.about-features {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--light-gray);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

.feature-item:hover {
    background: var(--gradient-primary);
    color: var(--white);
    transform: translateX(10px);
}

.feature-item i {
    font-size: 2rem;
    color: var(--accent);
    flex-shrink: 0;
}

.feature-item h4 {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    margin-bottom: 0.25rem;
}

.feature-item p {
    font-size: 0.9375rem;
    margin: 0;
    opacity: 0.9;
}

.about-image {
    position: sticky;
    top: 100px;
}

.about-image img {
    width: 100%;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
}

/* ===================================
   Welcome Speech Section
   =================================== */
.welcome-speech {
    padding: var(--spacing-3xl) 0;
    background: var(--white);
}

.welcome-content {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.chairman-info {
    position: sticky;
    top: 100px;
}

.chairman-image {
    width: 100%;
    margin-bottom: var(--spacing-md);
}

.chairman-image img {
    width: 100%;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
    display: block;
}

.chairman-details {
    text-align: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background: linear-gradient(135deg, #0B4F6C 0%, #1BA098 100%);
    border-radius: var(--radius-lg);
    color: var(--white);
}

.chairman-details h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
    color: var(--white);
}

.chairman-details .chairman-title {
    font-size: 1rem;
    color: var(--accent);
    font-weight: 600;
    margin: 0;
}

.chairman-photo {
    position: sticky;
    top: 100px;
}

.chairman-photo img {
    width: 100%;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
    margin-bottom: var(--spacing-md);
}

.chairman-name {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    color: var(--white);
}

.chairman-name h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.chairman-name p {
    font-size: 1rem;
    color: var(--accent);
    font-weight: 600;
}

.speech-text {
    background: var(--light-gray);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

.speech-text p {
    font-size: 1.0625rem;
    line-height: 1.8;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    text-align: justify;
}

.speech-text p:last-child {
    margin-bottom: 0;
}

.speech-text .greeting,
.speech-text .closing {
    font-style: italic;
    color: var(--primary);
    font-weight: 600;
}

.speech-text strong {
    color: var(--primary-dark);
    font-weight: 600;
}

/* ===================================
   Events Section
   =================================== */

.events {
    padding: var(--spacing-3xl) 0;
    background: var(--light-gray);
}

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

.event-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

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

.event-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-2xl);
}

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

.event-card.featured {
    background: var(--gradient-primary);
    color: var(--white);
}

.event-card.featured .event-icon {
    background: rgba(255, 255, 255, 0.2);
}

.event-card.featured h3,
.event-card.featured p {
    color: var(--white);
}

.featured-badge {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: var(--gradient-accent);
    color: var(--white);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
}

.event-icon {
    width: 70px;
    height: 70px;
    background: var(--gradient-secondary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

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

.event-card h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    color: var(--primary-dark);
    margin-bottom: var(--spacing-md);
}

.event-card p {
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

.event-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.9375rem;
    color: var(--primary);
    font-weight: 500;
}

.event-card.featured .event-meta {
    color: var(--accent);
}

.event-meta i {
    font-size: 1rem;
}

/* ===================================
   Venue Section
   =================================== */
.venue {
    padding: var(--spacing-3xl) 0;
    background: var(--white);
}

.venue-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.venue-card {
    background: var(--gradient-primary);
    color: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-xl);
    position: sticky;
    top: 100px;
}

.venue-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.venue-header i {
    font-size: 2.5rem;
    color: var(--accent);
}

.venue-header h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
}

.venue-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.venue-detail {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.venue-detail i {
    font-size: 1.5rem;
    color: var(--accent);
    flex-shrink: 0;
    margin-top: 0.25rem;
}

.venue-detail strong {
    display: block;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.venue-detail p {
    opacity: 0.9;
    line-height: 1.6;
}

.venue-map {
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.venue-map iframe {
    border-radius: var(--radius-xl);
}

/* ===================================
   Contact Section
   =================================== */
.contact {
    padding: var(--spacing-3xl) 0;
    background: var(--light-gray);
}

.contact-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.contact-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    text-align: center;
}

.contact-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.contact-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-secondary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
}

.contact-icon i {
    font-size: 2.5rem;
    color: var(--white);
}

.contact-card h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    color: var(--primary-dark);
    margin-bottom: var(--spacing-md);
}

.contact-card p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.contact-link {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--light-gray);
    border-radius: var(--radius-md);
    color: var(--primary);
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
    transition: all var(--transition-base);
}

.contact-link:hover {
    background: var(--gradient-primary);
    color: var(--white);
}

.organizer-info {
    text-align: center;
    color: var(--text-dark);
}

.organizer-info p {
    margin: 0;
}

/* ===================================
   Registration CTA Section
   =================================== */
.registration-cta {
    padding: var(--spacing-3xl) 0;
    background: var(--gradient-primary);
    color: var(--white);
    text-align: center;
}

.cta-content h2 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.cta-content>p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xl);
    opacity: 0.95;
}

.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--spacing-lg);
}

.cta-note {
    font-size: 0.9375rem;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    justify-content: center;
    opacity: 0.9;
}

.cta-note i {
    color: var(--accent);
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--primary-dark);
    color: var(--white);
    padding: var(--spacing-3xl) 0 var(--spacing-lg);
}

.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 {
    font-family: var(--font-heading);
    margin-bottom: var(--spacing-md);
    color: var(--accent);
}

.footer-section p {
    opacity: 0.9;
    line-height: 1.7;
}

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

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

.footer-social a:hover {
    background: var(--accent);
    transform: translateY(-3px);
}

.footer-section ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-section ul li {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    opacity: 0.9;
}

.footer-section ul li a:hover {
    color: var(--accent);
}

.footer-section ul li i {
    color: var(--accent);
    width: 20px;
}

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

.footer-bottom p {
    opacity: 0.8;
    font-size: 0.9375rem;
    margin: var(--spacing-xs) 0;
}

/* ===================================
   Scroll to Top Button
   =================================== */
.scroll-to-top {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 50px;
    height: 50px;
    background: var(--gradient-accent);
    color: var(--white);
    border: none;
    border-radius: var(--radius-full);
    font-size: 1.25rem;
    cursor: pointer;
    box-shadow: var(--shadow-xl);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: 999;
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-2xl);
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .about-image {
        position: relative;
        top: 0;
    }

    .venue-content {
        grid-template-columns: 1fr;
    }

    .venue-card {
        position: relative;
        top: 0;
    }
}

@media (max-width: 768px) {
    :root {
        --spacing-3xl: 3rem;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        flex-direction: column;
        align-items: flex-start;
        background: var(--white);
        padding: var(--spacing-3xl) var(--spacing-lg);
        box-shadow: var(--shadow-2xl);
        transition: right var(--transition-base);
    }

    .nav-links.active {
        right: 0;
    }

    .nav-link {
        color: var(--text-dark) !important;
        width: 100%;
        padding: var(--spacing-sm) 0;
    }

    .mobile-menu-toggle {
        display: block;
    }

    .section-title {
        font-size: 2rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .countdown {
        grid-template-columns: repeat(2, 1fr);
    }

    .countdown-value {
        font-size: 2rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .hero-cta .btn-large {
        width: 100%;
    }

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

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

    .chairman-photo {
        position: relative;
        top: 0;
    }

    .speech-text {
        padding: var(--spacing-md);
    }

    .cta-buttons {
        flex-direction: column;
        align-items: stretch;
    }

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

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }

    .container {
        padding: 0 var(--spacing-sm);
    }

    .hero-title {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .countdown-value {
        font-size: 1.5rem;
    }

    .countdown-label {
        font-size: 0.75rem;
    }
}

/* ===================================
   Mobile Responsive Styles
   =================================== */

/* Tablet and Mobile Devices */
@media (max-width: 768px) {

    /* Mobile Navigation Close Button */
    .mobile-menu-close {
        display: block;
        position: absolute;
        top: var(--spacing-md);
        right: var(--spacing-md);
        background: none;
        border: none;
        color: var(--primary-dark);
        font-size: 1.75rem;
        cursor: pointer;
        z-index: 1001;
        padding: var(--spacing-xs);
        transition: all var(--transition-base);
    }

    .mobile-menu-close:hover {
        color: var(--accent);
        transform: rotate(90deg);
    }

    .mobile-menu-close:active {
        transform: scale(0.9) rotate(90deg);
    }

    /* Welcome Speech Section - Mobile Layout */
    .welcome-content {
        grid-template-columns: 1fr;
        /* Single column layout */
        gap: var(--spacing-xl);
    }

    .chairman-info {
        position: static;
        /* Disable sticky positioning on mobile */
        top: auto;
    }

    /* About Section - Mobile Layout */
    .about-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    .about-image {
        position: static;
        top: auto;
    }

}

/* Small Mobile Devices */
@media (max-width: 480px) {

    /* Chairman Section Optimization */
    .chairman-image {
        max-width: 300px;
        margin: 0 auto var(--spacing-md);
    }

    .chairman-details {
        padding: var(--spacing-sm) var(--spacing-md);
    }

    .chairman-details h3 {
        font-size: 1.125rem;
    }

    .speech-text {
        padding: var(--spacing-md);
    }

    .speech-text p {
        font-size: 1rem;
    }
}