body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f3f3f3;
}

header {
    background-color: #68b98d;
    padding: 20px;
    color: white;
    text-align: center;
}

nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
}

nav ul li {
    display: inline;
    margin-right: 20px;
}

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

main {
    padding: 20px;
}

section {
    margin-bottom: 40px;
    clear: both;
}

footer {
    background-color: #68b98d;
    color: white;
    text-align: center;
    padding: 10px;
}

footer a:link {
    color: rgb(207, 228, 164);
}

footer a:hover {
    color: olivedrab;
}

iframe {
    width: 100%;
    height: 50%;
    border: none;
    margin-top: 1em;
}

.imagem_principal {
    max-width: 100%;
}

.div_esquerda {
    max-width: 35em;
    float: left;
    margin: 1em;
}

.div_direita {
    margin: 1em;
    padding: 1em;
    width: auto;
}