body {
    font-family: 'Comic Sans MS', cursive, sans-serif;
    background: url('fondo-libreta.jpg') repeat;
    text-align: center;
    margin: 0;
}

header {
    background: black;
    padding: 20px;
}

#titulo {
    color: white;
    transition: color 0.3s;
}

#titulo:hover {
    color: white;
    background: black;
    padding: 5px;
}

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

nav ul li {
    display: inline;
    margin: 0 15px;
}

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

.videos, .comentarios {
    margin: 20px;
    padding: 20px;
    background: white;
    border-radius: 10px;
    box-shadow: 5px 5px 10px gray;
}

footer {
    background: black;
    color: white;
    padding: 10px;
}

.social {
    color: white;
    margin: 10px;
    text-decoration: none;
    font-weight: bold;
}