body {
    background-color: #555;
    font-family: "Comic Sans MS", "Comic Sans", cursive;
}

.iframeDiv {
    margin-left: auto;
    margin-right: auto;
}

/* Add a black background color to the top navigation */
.topnav {
    background-color: #333;
    overflow: hidden;
    border-radius: 0px 0px 25px 25px;
}

.topbar {
    background-color: #333;
    overflow: hidden;
    border-radius: 25px 25px 0px 0px;
}

/* Style the links inside the navigation bar */
.topnav a {
    float: left;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
}

/* Change the color of links on hover */
.topnav a:hover {
    background-color: #ddd;
    color: black;
}

/* Add a color to the active/current link */
.topnav a.active {
    background-color: #3ad6c0;
    color: black;
}

.challenge img {
    width: 600px;
    border-radius: 25px;
    display:block;
    margin-left: auto;
    margin-right: auto;
}

.challenge h1 {
    text-align: center
}

.challenge p {
    text-align: center
}

.topbar img {
    height: 100px;
    border-radius: 25px;
}

.iframeDiv {
    width: 960px;
    height: 540px;
}

.content {

}

.content img {
    width: 600px;
    border-radius: 25px;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

h1 {
    text-align: center
}

h2 {
    text-align: center
}

p {
    text-align: center
}

a {
    text-align: center
}

.listholder {
    display: flex;
    flex-direction: row;
    width: 50%;
    margin-left: auto;
    margin-right: auto;
}

.list {
    display: flex;
    flex-direction: column;
    margin: 5px;
    margin-left: auto;
    margin-right: auto;
}

a:link {
    color: #89e6b4;
    text-decoration: none;
}