* {
    box-sizing: border-box;
}

section#tutorial {
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #000;
    margin: 0;
    padding: 10px;
}

section#tutorial h1{
    color: #fff;
    font-family: "Tahoma";
    text-align: center;
    max-width: 100%;
}

div.video {
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #333333;
    padding: 5px;
    
}

div.video h2 {
    max-width: 100%;
    font-family: "tahoma";
    font-size: 1.5em;
    font-weight: 700;
    color: #fff;
    text-align: center;
    padding: 10px;
    margin: 5px;
}

div.video iframe {
    max-width: 100%;
    height: 50%;
    border: 5px solid #fff;
}

div.video iframe:hover {
    border: 10px solid #6699cc;
    transition:  border 1s;
}

@media screen and (min-width: 768px){
    div.video iframe {
        max-width: 100%;
        height: 315px;
    }
}

@media screen and (min-width: 500px){
    div.video iframe {
        max-width: 100%;
        height: 315px;
    }
}