o-header {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            padding: 6rem 0;
            text-align: center;
        }
        
        .demo-nav {
            position: sticky;
            top: 0;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid #e5e7eb;
            z-index: 1000;
        }
        
        .demo-nav .container {
            display: flex;
        