* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #f59e0b;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --white: #ffffff;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Hero Section */
.hero {
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 80px;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('hero-pattern.svg') repeat;
    opacity: 0.1;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: var(--white);
    max-width: 800px;
    margin: 0 auto;
    animation: fadeInUp 1s ease;
}

.hero-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    font-weight: 500;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    font-weight: 300;
}

.hero-details {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.detail-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
}

.icon {
    font-size: 1.5rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
}

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

.btn-primary:hover {
    background: #d97706;
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(245, 158, 11, 0.3);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    color: var(--white);
    border: 2px solid var(--white);
}

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

.hero-wave {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    overflow: hidden;
    line-height: 0;
}

.hero-wave svg {
    position: relative;
    display: block;
    width: calc(100% + 1.3px);
    height: 120px;
}

.hero-wave path {
    fill: var(--white);
}

/* Conference Info Section */
.conference-info {
    padding: 4rem 0;
    background: var(--bg-light);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.info-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

.info-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.info-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.info-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* About Section */
.about-section {
    padding: 5rem 0;
    background: var(--white);
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.header-line {
    width: 100px;
    height: 4px;
    background: linear-gradient(to right, var(--primary-color), var(--accent-color));
    margin: 0 auto;
    border-radius: 2px;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.about-content p {
    margin-bottom: 1.5rem;
    color: var(--text-light);
    line-height: 1.8;
}

.about-image {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.about-image img {
    width: 100%;
    height: 400px;
    object-fit: cover;
    display: block;
}

/* Host Section */
.host-section {
    padding: 5rem 0;
    background: var(--bg-light);
}

.host-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.host-image {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.host-image img {
    width: 100%;
    height: 400px;
    object-fit: cover;
    display: block;
}

.host-badge {
    position: absolute;
    bottom: 20px;
    left: 20px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1.5rem;
    border-radius: 15px;
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1.5rem;
}

.host-badge span {
    display: block;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-light);
    margin-top: 0.5rem;
}

.host-info h2 {
    color: var(--text-dark);
    margin-bottom: 1.5rem;
    font-size: 2rem;
}

.host-info p {
    margin-bottom: 1.5rem;
    color: var(--text-light);
    line-height: 1.8;
}

/* Tracks Section */
.tracks-section {
    padding: 5rem 0;
    background: var(--white);
}

.tracks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.track-card {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.track-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(37, 99, 235, 0.3);
}

.track-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.track-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

/* Important Dates */
.dates-section {
    padding: 5rem 0;
    background: var(--bg-light);
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 100%;
    background: var(--primary-color);
}

.timeline-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    position: relative;
}

.timeline-item:nth-child(odd) {
    flex-direction: row-reverse;
}

.timeline-icon {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    z-index: 2;
    box-shadow: 0 0 0 10px var(--white), 0 0 0 12px var(--primary-color);
}

.timeline-content {
    width: 45%;
    background: var(--white);
    padding: 1.5rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
}

.timeline-content h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.date {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.status {
    font-size: 0.9rem;
    color: var(--text-light);
}

.status.extended {
    color: #ef4444;
    font-weight: 600;
}

/* Past Events */
.past-events {
    padding: 5rem 0;
    background: var(--white);
}

.events-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.event-card {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
}

.event-badge {
    width: 180px;
    height: 220px;
    background: linear-gradient(135deg, #1e3a8a, #1e40af);
    border-radius: 15px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    color: var(--white);
    box-shadow: var(--shadow-lg);
    transition: transform 0.3s ease;
}

.event-badge:hover {
    transform: translateY(-10px) scale(1.05);
}

.badge-text {
    font-size: 1.2rem;
    font-weight: 700;
    text-align: center;
}

.badge-year {
    font-size: 3rem;
    font-weight: 700;
    text-align: center;
}

.badge-ieee {
    font-size: 1.5rem;
    font-weight: 700;
    text-align: center;
    border-top: 2px solid rgba(255, 255, 255, 0.3);
    padding-top: 0.5rem;
}

/* Footer */
.footer {
    background: #1f2937;
    color: var(--white);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--accent-color);
}

.footer-section p {
    color: #d1d5db;
    line-height: 1.8;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #d1d5db;
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #9ca3af;
}

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

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInFromRight {
    from {
        opacity: 0;
        transform: translateX(100%);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Selection Color */
::selection {
    background: var(--primary-color);
    color: var(--white);
}

::-moz-selection {
    background: var(--primary-color);
    color: var(--white);
}

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    box-shadow: var(--shadow);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: var(--white);
    box-shadow: var(--shadow-lg);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo h2 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 700;
    text-decoration: none;
}

/* Nav Menu */
.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

/* Submit Button */
.btn-submit {
    background: var(--accent-color);
    color: var(--white) !important;
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

/* Nav Toggle (Hamburger Button) */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 25px;
    background: none;
    border: none;
    cursor: pointer;
    z-index: 1001;
    padding: 0;
    position: relative;
}

.nav-toggle span {
    width: 100%;
    height: 3px;
    background: var(--text-dark);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 2px;
    display: block;
    transform-origin: center;
}

/* Enhanced Hamburger Animation for Overlay */
.nav-toggle.open span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
    background: var(--primary-color);
}

.nav-toggle.open span:nth-child(2) {
    opacity: 0;
    transform: translateX(-10px);
}

.nav-toggle.open span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
    background: var(--primary-color);
}

/* Mobile Menu - Slide Overlay from Right with Blur Background */
@media (max-width: 968px) {
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        flex-direction: column;
        background: rgba(255, 255, 255);
        width: 100%;
        height: 100vh;
        text-align: center;
        transition: right 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        box-shadow: none;
        padding: 80px 2rem 2rem;
        gap: 1.5rem;
        justify-content: flex-start;
        z-index: 999;
    }

    .nav-menu.open {
        right: 0;
    }

    .nav-menu::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: linear-gradient(135deg, rgba(37, 99, 235, 0.05) 0%, rgba(245, 158, 11, 0.05) 100%);
        z-index: -1;
    }

    .nav-menu li {
        width: 100%;
        opacity: 0;
        transform: translateX(50px);
        transition: all 0.4s ease;
    }

    .nav-menu.open li {
        opacity: 1;
        transform: translateX(0);
    }

    /* Staggered animation for menu items */
    .nav-menu.open li:nth-child(1) { transition-delay: 0.1s; }
    .nav-menu.open li:nth-child(2) { transition-delay: 0.15s; }
    .nav-menu.open li:nth-child(3) { transition-delay: 0.2s; }
    .nav-menu.open li:nth-child(4) { transition-delay: 0.25s; }
    .nav-menu.open li:nth-child(5) { transition-delay: 0.3s; }
    .nav-menu.open li:nth-child(6) { transition-delay: 0.35s; }
    .nav-menu.open li:nth-child(7) { transition-delay: 0.4s; }
    .nav-menu.open li:nth-child(8) { transition-delay: 0.45s; }
    .nav-menu.open li:nth-child(9) { transition-delay: 0.5s; }

    .nav-menu a {
        display: block;
        padding: 1rem 0;
        font-size: 1.2rem;
        font-weight: 600;
        color: var(--text-dark);
        transition: all 0.3s ease;
        border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    }

    .nav-menu a:hover {
        color: var(--primary-color);
        transform: translateX(10px);
        border-bottom-color: var(--primary-color);
    }

    .nav-menu .btn-submit {
        margin-top: 1rem;
        border: 2px solid var(--accent-color);
        border-radius: 25px;
        padding: 0.75rem 1.5rem;
        background: var(--accent-color);
        color: var(--white) !important;
        font-size: 1.1rem;
        border-bottom: none;
    }

    .nav-menu .btn-submit:hover {
        transform: translateY(-3px);
        box-shadow: 0 10px 20px rgba(245, 158, 11, 0.3);
    }

    .nav-toggle {
        display: flex;
        z-index: 1000;
    }

    .nav-toggle.open {
        position: fixed;
        right: 20px;
        top: 20px;
    }

    .nav-toggle.open span {
        background: var(--primary-color);
    }

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

    .hero-subtitle {
        font-size: 1.2rem;
    }

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

    .timeline::before {
        left: 30px;
    }

    .timeline-item,
    .timeline-item:nth-child(odd) {
        flex-direction: row;
    }

    .timeline-icon {
        position: absolute;
        left: 0;
    }

    .timeline-content {
        width: calc(100% - 80px);
        margin-left: 80px;
    }

    .info-grid,
    .tracks-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-details {
        flex-direction: column;
        gap: 1rem;
    }

    .section-header h2 {
        font-size: 2rem;
    }

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

    .btn {
        width: 100%;
    }

    .host-badge {
        font-size: 1.2rem;
        padding: 1rem;
    }

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

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

    /* Adjust mobile menu for smaller screens */
    .nav-menu {
        padding: 70px 1.5rem 2rem;
    }

    .nav-menu a {
        font-size: 1.1rem;
        padding: 0.875rem 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

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

    .hero-subtitle {
        font-size: 1rem;
    }

    .detail-item {
        font-size: 0.85rem;
        padding: 0.5rem 1rem;
    }

    .section-header h2 {
        font-size: 1.75rem;
    }

    .info-card,
    .track-card {
        padding: 1.5rem;
    }

    .about-image img,
    .host-image img {
        height: 300px;
    }

    /* Further adjustments for very small screens */
    .nav-menu {
        padding: 60px 1rem 2rem;
    }

    .nav-menu a {
        font-size: 1rem;
        padding: 0.75rem 0;
    }

    .nav-toggle {
        width: 25px;
        height: 20px;
    }
}