body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    text-align: center;
    background-color: #f5f5f5;
}

header {
    background-color: #0077b6;
    color: white;
    padding: 20px;
}

nav ul {
    list-style: none;
    padding: 0;
    background-color: #005f8f;
    margin: 0;
}

nav ul li {
    display: inline;
    padding: 15px;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: bold;
}

section {
    padding: 20px;
    margin: 20px auto;
    background: white;
    border-radius: 10px;
    width: 80%;
    box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.1);
}

.plano {
    display: inline-block;
    width: 30%;
    padding: 15px;
    margin: 10px;
    background: #0077b6;
    color: white;
    border-radius: 5px;
}

footer {
    background-color: #0077b6;
    color: white;
    padding: 10px;
    margin-top: 20px;
}