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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
}

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

/* Header */
.header {
    background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
    color: white;
    padding: 40px 0;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.conference-info h1 {
    font-size: 2.2rem;
    margin-bottom: 10px;
}

.location-date {
    font-size: 1.2rem;
    margin-bottom: 5px;
}

.theme {
    font-style: italic;
    font-size: 1.1rem;
}

.header-links {
    display: flex;
    align-items: center;
    gap: 10px;
}

.header-links .link {
    color: white;
    text-decoration: none;
    font-weight: 500;
}

.header-links .link:hover {
    text-decoration: underline;
}

.header-links .separator {
    color: rgba(255, 255, 255, 0.7);
}

/* Navigation */
.navbar {
    background-color: #0d2137;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.nav-menu {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: block;
    padding: 15px 20px;
    color: white;
    text-decoration: none;
    transition: background-color 0.3s;
}

.nav-link:hover,
.nav-link.active {
    background-color: #1e3c72;
}

/* Dropdown */
.dropdown {
    position: relative;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #0d2137;
    list-style: none;
    min-width: 200px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
}

.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-link {
    display: block;
    padding: 12px 20px;
    color: white;
    text-decoration: none;
    transition: background-color 0.3s;
}

.dropdown-link:hover {
    background-color: #1e3c72;
}

/* Main Content */
.main-content {
    padding: 60px 0;
    min-height: 500px;
}

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

.welcome-section h2 {
    font-size: 2rem;
    color: #1e3c72;
    margin-bottom: 20px;
}

.welcome-section p {
    font-size: 1.1rem;
    color: #666;
}

/* Footer */
.footer {
    background-color: #0d2137;
    color: white;
    padding: 40px 0 20px;
}

.footer-content {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.footer-section {
    margin: 20px;
}

.footer-section h3 {
    margin-bottom: 10px;
    font-size: 1.2rem;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: 20px;
    text-align: center;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.7);
}

/* Responsive */
@media (max-width: 768px) {
    .header-top {
        flex-direction: column;
        text-align: center;
    }

    .nav-menu {
        flex-direction: column;
    }

    .nav-link {
        padding: 12px 15px;
        text-align: center;
    }

    .dropdown-menu {
        position: static;
        box-shadow: none;
    }

    .footer-content {
        flex-direction: column;
        align-items: center;
    }
}