body {
    background: #3EA1FF repeat;
    
}
header h1{
    color:green;
    text-align: center;
    font-size: 3em;
}

header h2 {
    margin: 10px;
    padding: 160px;
    background-color: white;
    background-image: url(https://as01.epimg.net/futbol/imagenes/2019/05/27/champions/1558936886_306072_1558937370_noticia_normal.jpg);
    color: black;
    opacity: 0.7;
    border-radius: 20px;
    text-align: center;
    font-variant: small-caps;
}

header h3 {
    margin: 60px;
    padding: 10px;
    background-color: white;
    border-radius: 20px;
    opacity: 0.6;
    text-align: center;
    color: rebeccapurple;
    
}

#introduccion h4 {
    margin: 40px;
    padding: 10px;
    text-align: center;
    color: green;
    font-size: 2em;
}

#videos {
    background-color: white;
    border-radius: 20px;
    opacity: 0.8;
    margin: 80px;
    padding: 10px;
    text-align: center;
    color: green;
    font-size: 1em;
}


    
#videos iframe {
     border: 10px solid green;
    border-radius: 20px;
    margin: 0 auto;
    display: block;
    opacity:0.9;
}

footer {
    background-color: yellowgreen;
    margin: 20px;
    border-radius: 20px;
    height: 2em;
    
}

footer p {
    text-align: center;
    font-size: 100%;
}