body {
    font-family: sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background-color: #333;
    color: #fff;
    padding: 1rem;
    text-align: center;
}

header img.logo{
    max-width: 100px;
    border-radius: 50%;
}

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

nav li {
    display: inline;
    margin: 0 1rem;
}

nav a {
    color: #fff;
    text-decoration: none;
}

main {
    padding: 2rem;
}

main img.principal{
    max-width: 100%;
}

footer {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 1rem;
    position: fixed;
    bottom: 0;
    width: 100%;
}

/* Estils de Bootstrap */
.btn-primary {
    background-color: #007bff;
    border-color: #007bff;
}

.btn-primary:hover {
    background-color: #0069d9;
    border-color: #0062cc;
}

.alert-success {
    background-color: #d4edda;
    border-color: #c3e6cb;
    color: #155724;
}

/* Pseudoclasses */
a:hover {
    text-decoration: underline;
}

/* Ombres i costats arrodonits */
.principal {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
}