body {
    font-family: Arial, sans-serif;
    max-width: 900px;
    margin: 0 auto;
    padding: 40px;
}

nav {
    margin-bottom: 30px;
}

nav a {
    margin-right: 20px;
    text-decoration: none;
    color: blue;
}

form {
    max-width: 500px;
}

input,
textarea {
    width: 100%;
    padding: 10px;
    margin-top: 5px;
    margin-bottom: 15px;
    box-sizing: border-box;
}

button {
    padding: 10px 20px;
    cursor: pointer;
}