body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    line-height: 1.6;
}
header {
    background: #015958;
    color: white;
    padding: 1em;
    text-align: center;
}
nav a {
    margin: 0 10px;
    color: #ccf1f0;
    text-decoration: none;
}
main {
    padding: 20px;
}
footer {
    background: #eee;
    padding: 10px;
    text-align: center;
}
a.whatsapp {
    display: inline-block;
    background: #25d366;
    color: white;
    padding: 10px 15px;
    margin-top: 20px;
    text-decoration: none;
    border-radius: 5px;
}