* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    display: grid;
    grid-template-columns: 20% 80%;
    grid-template-areas:
        'header header'
        'sidebar videos'
        'footer footer';
    font-family: "Erica One", sans-serif;
    font-weight: 200;
    font-style: normal;
    background-image: linear-gradient(to bottom, rgb(59, 0, 161), black);
    color: white;
    position: relative;
}

header {
    display: flex;
    grid-area: header;
    background-color: rgb(59, 0, 161);
    color: white;
    align-items: center;
    border-bottom: 3px solid white;
    margin-bottom: 25px;
    font-size: 125%;
}

header img {
    border-radius: 50vh;
    padding: 1em;
    max-width: 200px;
}

#nav_list {
    grid-area: sidebar;
    display: flex;
    flex-direction: column;
}

#nav_list ul {
    position: sticky;
    top: 20px;
}

#nav_list li {
    margin-bottom: 8px;
}

#nav_list a {
    display: block;
    background-color: white;
    color: black;
    padding: 8px 20px;
    border-radius: 8px;
    text-decoration: none;
    transition: all ease-in-out 200ms;
}

#nav_list a:hover {
    background-color: black;
    color: white;
}

.btn {
    display: inline-block;
    align-self: center;
    margin-top: 1em;
    padding: 1em 2em;
    background-color: green;
    color: aliceblue;
    text-decoration: none;
    font-weight: 600;
    border-radius: 10px;
    box-shadow: 1px 1px 12px 2px gray;
}

.return-to-top {
    display: none;
    /* Hidden by default */
    position: fixed;
    left: 75px;
    bottom: 75px;
    z-index: 9999;
    /* Make sure it does not overlap */
    cursor: pointer;
    /* Add a mouse pointer on hover */
    border: none;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, .5);
    transition: all ease-in-out 300ms;
}

.return-to-top img {
    max-width: 50px;
}

.return-to-top:hover {
    background-color: rgba(255, 0, 255, 1);
}


section {
    max-width: 75%;
    margin: 0 auto;
}

main {
    grid-area: videos;
}

.videowrapper {
    position: relative;
    padding-bottom: 56.25%;
    /* 16:9 */
    padding-top: 25px;
    height: 0;
    margin: 0 auto;
    border: none;
}

.videowrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: 5px;
}

.caption {
    margin-top: 10px;
    margin-bottom: 30px;
    font-family: Arial, Helvetica, sans-serif;
    border-left: 25px solid white;
    padding-left: 10px;
    max-width: 75%;

}

article h4 {
    font-size: 150%;
    padding-bottom: 10px;
}

footer {
    grid-area: footer;
    font-family: Arial, Helvetica, sans-serif;
    padding: 2em;
    margin-top: 6em;
    margin: auto;
}





@media (max-width: 600px) {
    #nav_list {
        display: none;
    }

    header {
        flex-direction: column;
        padding-bottom: 20px;
        font-size: 100%;
    }

    body {
        grid-template-columns: 1fr;
        grid-template-areas:
            'header'
            'videos'
            'footer';
    }

    section {
        max-width: 100%;
    }

    h4 {
        font-size: 80%;
        padding: 1em;

    }

    .videowrapper {
        border: none;
    }
}