body {
    font-family: Arial, Helvetica, sans-serif;
    margin: 0;
    padding: 0;
    background: #f3f3f3;
    color: #333;
}

header {
    background: #222;
    color: white;
    padding: 20px;
    text-align: center;
}

.intro, .bloque {
    max-width: 800px;
    margin: 30px auto;
    padding: 20px;
    background: white;
    border-radius: 6px;
    box-shadow: 0 0 5px rgba(0,0,0,0.1);
}

.bloque h2 {
    margin-top: 0;
}

img {
    width: 100%;
    margin-top: 15px;
    border-radius: 5px;
}

footer {
    text-align: center;
    padding: 15px;
    background: #222;
    color: white;
    margin-top: 40px;
}