:root {
        --primary-color: #2c3e50;
        --secondary-color: #3498db;
        --text-color: #333;
        --background-color: #ffffff;
        --light-gray: #f8f9fa;
        --border-color: #e9ecef;
        --shadow: 0 2px 10px rgba(0,0,0,0.1);
        --max-width: 1200px;
        --container-padding: 20px;
    }
    
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }
    
    body {
        font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
        line-height: 1.6;
        color: var(--text-color);
        background-color: var(--background-color);
    }
    
    .container {
        max-width: var(--max-width);
        margin: 0 auto;
        padding: 0 var(--container-padding);
    }
    
    .header {
        background: var(--light-gray);
        border-bottom: 1px solid var(--border-color);
        padding: 20px 0;
        margin-bottom: 40px;
    }
    
    .header-content {
        display: flex;
        align-items: center;
        justify-content: center;
        flex-wrap: wrap;
        gap: 20px;
    }
    
    .logo-section {
        display: flex;
        align-items: center;
        gap: 15px;
    }
    
    .logo {
        width: 60px;
        height: 60px;
        border-radius: 8px;
        display: none;
    }
    
    .site-title {
        font-size: 2rem;
        font-weight: 700;
        color: var(--primary-color);
        margin: 0;
        display: none;
    }
    
    .nav {
        display: flex;
        gap: 30px;
    }
    
    .nav a {
        color: var(--text-color);
        text-decoration: none;
        font-weight: 500;
        padding: 8px 16px;
        border-radius: 6px;
        transition: all 0.2s ease;
    }
    
    .nav a:hover {
        background: var(--secondary-color);
        color: white;
    }
    
    .nav a.active {
        background: var(--primary-color);
        color: white;
    }
    
    .main {
        min-height: 60vh;
    }
    
    .content {
        background: white;
        padding: 40px;
        border-radius: 12px;
        box-shadow: var(--shadow);
        margin-bottom: 40px;
    }
    
    h1 {
        color: var(--primary-color);
        font-size: 2.5rem;
        margin-bottom: 20px;
        border-bottom: 3px solid var(--secondary-color);
        padding-bottom: 10px;
    }
    
    h2 {
        color: var(--primary-color);
        font-size: 1.8rem;
        margin: 30px 0 15px 0;
    }
    
    h3 {
        color: var(--secondary-color);
        font-size: 1.4rem;
        margin: 25px 0 15px 0;
    }
    
    p {
        margin-bottom: 15px;
        color: var(--text-color);
    }
    
    strong {
        color: var(--primary-color);
    }
    
    em {
        color: var(--secondary-color);
    }
    
    code {
        background: var(--light-gray);
        padding: 2px 6px;
        border-radius: 4px;
        font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
        font-size: 0.9em;
    }
    
    hr {
        border: none;
        height: 2px;
        background: linear-gradient(to right, transparent, var(--border-color), transparent);
        margin: 40px 0;
        border-radius: 2px;
    }
    
    a {
        color: var(--secondary-color);
        text-decoration: none;
    }
    
    a:hover {
        text-decoration: underline;
    }
    
    .content-image {
        max-width: 100%;
        height: auto;
        display: block;
        margin: 20px auto;
    }
    
    .content-table {
        width: 100%;
        border-collapse: collapse;
        margin: 20px 0;
        background: white;
        border-radius: 8px;
        overflow: hidden;
        box-shadow: var(--shadow);
    }
    
    .content-table th,
    .content-table td {
        padding: 12px 15px;
        text-align: left;
        border-bottom: 1px solid var(--border-color);
    }
    
    .content-table th {
        background: var(--light-gray);
        font-weight: 600;
        color: var(--primary-color);
        border-bottom: 2px solid var(--secondary-color);
    }
    
    .content-table tr:hover {
        background: var(--light-gray);
    }
    
    .content-table tr:last-child td {
        border-bottom: none;
    }
    
    .session-card {
        background: var(--light-gray);
        border: 1px solid var(--border-color);
        border-radius: 12px;
        padding: 25px;
        margin: 20px 0;
        transition: all 0.3s ease;
        box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    }
    
    .session-card:hover {
        background: #e9ecef;
        box-shadow: 0 4px 15px rgba(0,0,0,0.1);
        transform: translateY(-2px);
    }
    
    .session-card h3 {
        margin-top: 0;
        color: var(--primary-color);
        border-bottom: 2px solid var(--secondary-color);
        padding-bottom: 10px;
    }
    
    .rsvp-attendees {
        background: rgba(52, 152, 219, 0.1);
        border-left: 3px solid var(--secondary-color);
        padding: 12px 15px;
        margin: 15px 0;
        border-radius: 8px;
        font-size: 0.95em;
    }
    
    .rsvp-count {
        font-weight: 600;
        color: var(--secondary-color);
    }
    
    .attendee-names {
        color: var(--text-color);
        margin-top: 5px;
    }
    
    .past-session {
        opacity: 0.85;
        border-left: 4px solid var(--secondary-color);
    }
    
    .past-session h3 {
        color: #666;
    }
    
    .no-sessions-message {
        background: linear-gradient(135deg, var(--light-gray), #f0f4f8);
        border: 2px dashed var(--border-color);
        border-radius: 16px;
        padding: 40px;
        margin: 30px 0;
        text-align: center;
        color: var(--text-color);
    }
    
    .no-sessions-message h3 {
        color: var(--secondary-color);
        margin-bottom: 20px;
    }
    
    .cta-button {
        display: inline-block;
        background: var(--secondary-color);
        color: white;
        padding: 15px 30px;
        text-decoration: none;
        border-radius: 8px;
        font-weight: 600;
        font-size: 1.1rem;
        margin: 20px 0;
        transition: all 0.3s ease;
        box-shadow: 0 4px 15px rgba(52, 152, 219, 0.3);
    }
    
    .cta-button:hover {
        background: var(--primary-color);
        transform: translateY(-2px);
        box-shadow: 0 6px 20px rgba(52, 152, 219, 0.4);
        color: white;
        text-decoration: none;
    }
    
    .cta-button:active {
        transform: translateY(0);
    }
    
    .button-container {
        text-align: center;
        margin: 30px 0;
    }
    
    .footer {
        background: var(--primary-color);
        color: white;
        text-align: center;
        padding: 30px 0;
        margin-top: 60px;
    }
    
    .footer-content {
        text-align: center;
    }
    
    .footer-content p {
        margin-bottom: 10px;
        color: white;
    }
    
    .footer-content a {
        color: white;
        text-decoration: none;
        margin: 0 10px;
    }
    
    .footer-content a:hover {
        color: var(--secondary-color);
    }
    
    .footer-content em {
        font-size: 0.9em;
        opacity: 0.8;
        font-style: italic;
    }
    
    @media (max-width: 768px) {
        .container {
            padding: 0 15px;
        }
        
        .header-content {
            flex-direction: column;
            text-align: center;
        }
        
        .nav {
            gap: 15px;
        }
        
        .content {
            padding: 25px;
        }
        
        .content-table {
            font-size: 0.9rem;
        }
        
        .content-table th,
        .content-table td {
            padding: 8px 10px;
        }
        
        .cta-button {
            padding: 12px 25px;
            font-size: 1rem;
        }
        
        h1 {
            font-size: 2rem;
        }
        
        h2 {
            font-size: 1.5rem;
        }
    }
    
    @media (max-width: 480px) {
        .site-title {
            font-size: 1.5rem;
        }
        
        .nav {
            flex-direction: column;
            gap: 10px;
        }
        
        .nav a {
            padding: 10px;
            text-align: center;
        }
    }