body {
    font-family: Arial, sans-serif;
    margin: 0;
    background-color: #f8f8f8;
}

header, nav, footer {
    background-color: #192a56;
    color: #fff;
    padding: 18px;
    text-align: center;
}

nav a {
    color: #fff;
    text-decoration: none;
    margin: 0 10px;
}

main {
    background: #fff;
    max-width: 700px;
    margin: 24px auto;
    padding: 24px;
    box-shadow: 0 2px 8px rgba(25, 42, 86, 0.10);
}

h1, h2, h3 {
    color: #273c75;
}