*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    font-family: "Roboto", sans-serif;
    /* border: 2px solid #ffbb00; */
}

header {
    background-color: #6e78cc;
    color: #fff;
    padding: 20px;
    text-align: center;
    width: 750px;
    margin: 0 auto;
}



.container {
    /* border: 2px solid #00ff15; */
    display: flex;
    flex-direction: row;
    width: 750px;
    margin: 0 auto;
}

.left-column {
    width: 20%;
    background-color: #f0f0f0;
    padding: 20px;
    margin: 0 auto;
}

.right-column {
    width: 80%;
    padding: 20px;
}

.left-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.left-column li {
    margin-bottom: 10px;
}

.left-column a {
    text-decoration: none;
    color: #337ab7;
}

.right-column div {
    display: none;
}

.right-column div:target {
    display: block;
}

.image-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

.image-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 20px;
}