header {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 1.8rem;
    margin-bottom: 15px;
    text-align: center;
}

nav ul {
    display: flex;
    justify-content: center;
    list-style: none;
    flex-wrap: wrap;
}

nav ul li {
    margin: 0 10px;
}

nav ul li a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    padding: 5px 10px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

nav ul li a:hover {
    background-color: var(--dark-blue);
}