header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px; /* Adjust the height as needed */
    background: linear-gradient(135deg, #1e3c72, #2a5298);
    z-index: 999;
    border: none;
    box-shadow: none; /* Remove shadows if unnecessary */
}

main {
    margin-top: 60px; /* Match the header height */
}