body {
    margin: 0;
    font-family: Arial, sans-serif;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100px; /* adjust to match your header image height */
    background: #333; /* optional */
    padding: 0;
    margin: 0;
    display: flex;
    align-items: center;
}

header img {
    height: 100%;
    width: auto;
}

#sidebar {
    position: fixed;
    top: 100px; /* same as header height */
    left: 0;
    width: 220px;
    bottom: 0;
    background: #444;
    color: white;
    padding: 10px;
    overflow-y: auto;
}

#sidebar a {
    color: white;
    text-decoration: none;
}

main {
    margin-left: 240px;
    margin-top: 110px; /* slightly more than header height */
    padding: 20px;
}