body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background: #f8f9fa;
}

nav {
    background: #2c3e50;
    padding: 15px;
    margin-bottom: 20px;
}

nav a {
    color: white;
    text-decoration: none;
    margin-right: 20px;
    padding: 5px 10px;
}

nav a:hover {
    background: #34495e;
    border-radius: 3px;
}

.study {
    border: 1px solid #ddd;
    padding: 15px;
    margin: 10px 0;
    border-radius: 5px;
    background: white;
}

.pathology {
    border-left: 4px solid #e53935;
    background: #ffebee;
}

.normal {
    border-left: 4px solid #43a047;
    background: #e8f5e8;
}

.btn {
    background: #3498db;
    color: white;
    padding: 8px 15px;
    text-decoration: none;
    border-radius: 3px;
    margin-right: 10px;
    display: inline-block;
}

.btn:hover {
    background: #2980b9;
}