    body { 
        font-family: 'Ubuntu', sans-serif; 
        background-color: #f8f9fa;
    }
    
    .concept-container {
        max-width: 1400px;
        margin: 0 auto;
        padding: 20px;
    }
    
    .info-card {
        background: white;
        border-radius: 12px;
        box-shadow: 0 2px 8px rgba(0,0,0,0.1);
        border: 1px solid #e9ecef;
        margin-bottom: 20px;
        overflow: hidden;
    }
    
    .info-card-header {
        background: linear-gradient(135deg, #43883d 0%, #3F8827 100%);
        color: white;
        padding: 16px 20px;
        font-weight: 600;
        border-bottom: none;
    }
    
    .info-card-body {
        padding: 20px;
    }
    
    .metadata-item {
        background: #f8f9fa;
        border-radius: 8px;
        padding: 12px 16px;
        margin-bottom: 12px;
        border-left: 4px solid #43883d;
    }
    
    .metadata-label {
        font-size: 0.85rem;
        color: #6c757d;
        font-weight: 500;
        margin-bottom: 4px;
    }
    
    .metadata-value {
        font-weight: 600;
        color: #212529;
    }
    
    .preview-container {
        background: white;
        border-radius: 12px;
        box-shadow: 0 2px 8px rgba(0,0,0,0.1);
        border: 1px solid #e9ecef;
        overflow: hidden;
        height: 600px;
    }
    
    .preview-iframe {
        width: 100%;
        height: 100%;
        border: none;
    }
    
    .no-preview {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        height: 100%;
        text-align: center;
        padding: 40px;
        color: #6c757d;
    }
    
    .no-preview-icon {
        font-size: 4rem;
        color: #43883d;
        margin-bottom: 20px;
    }
    
    .btn-action {
        background: linear-gradient(135deg, #43883d 0%, #3F8827 100%);
        color: white;
        border: none;
        padding: 12px 24px;
        border-radius: 8px;
        font-weight: 600;
        text-decoration: none;
        display: inline-flex;
        align-items: center;
        transition: all 0.3s ease;
        margin-bottom: 12px;
        width: 100%;
        justify-content: center;
    }
    
    .btn-action:hover {
        color: white;
        transform: translateY(-2px);
        box-shadow: 0 4px 12px rgba(67, 136, 61, 0.3);
    }
    
    .btn-outline-action {
        background: transparent;
        color: #43883d;
        border: 2px solid #43883d;
        padding: 12px 24px;
        border-radius: 8px;
        font-weight: 600;
        text-decoration: none;
        display: inline-flex;
        align-items: center;
        transition: all 0.3s ease;
        width: 100%;
        justify-content: center;
    }
    
    .btn-outline-action:hover {
        background: #43883d;
        color: white;
        transform: translateY(-2px);
    }
    
    .header-title {
        background: white;
        border-radius: 12px;
        box-shadow: 0 2px 8px rgba(0,0,0,0.1);
        border: 1px solid #e9ecef;
        padding: 24px;
        margin-bottom: 24px;
        text-align: center;
    }
    
    .header-title h1 {
        color: #43883d;
        font-weight: 700;
        margin-bottom: 8px;
    }
    
    .header-subtitle {
        color: #6c757d;
        font-size: 1.1rem;
    }
    
    .back-btn {
        background: #6c757d;
        color: white;
        border: none;
        padding: 10px 20px;
        border-radius: 8px;
        text-decoration: none;
        display: inline-flex;
        align-items: center;
        font-weight: 500;
        margin-bottom: 20px;
        transition: all 0.3s ease;
    }
    
    .back-btn:hover {
        background: #5a6268;
        color: white;
        transform: translateY(-1px);
    }
    
    .content-card {
        background: white;
        border-radius: 12px;
        box-shadow: 0 2px 8px rgba(0,0,0,0.1);
        border: 1px solid #e9ecef;
        padding: 24px;
        margin-bottom: 20px;
    }
    
    .content-text {
        line-height: 1.6;
        color: #495057;
    }