:root {
    --borderstyle: solid;
    --textalign: center;
    --font_code: Menlo,Consolas,Monaco,Liberation Mono,Lucida Console,monospace;
    --code_align: left;
}

* {
    color: grey;
    background-color: black;
    border-color: forestgreen;
    /* border-style: none; */
}

header {
    text-align: var(--textalign);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-style: solid;
    height: 100px;
}

header .header_name {
    margin-left: 0px;
    padding-left: 40px;
    border-style: none;
    background-color: lightgreen;
}

header .header_links {
    border-style: none;
}

header h1 {
    font-size: 50px;
    background-color: transparent;
    border-style: none;
}

header nav ul {
    list-style: none;
    display: flex;
    border-style: none;
}

header nav li {
    border-style: none;
    padding-right: 10px;
}

#image_header {
    /* code from Xpert */
    background-size: contain;
    background-position: center;
    display: flex;
    justify-content: right;
    height: 100px;
    border-style: none;
}

#image_header #image_header_subtitle {
    margin-right: 0px;
    padding-right: 0px;
    border-style: none;
}

.row {
    display: flex;
    direction: horizontal;
    border-style: solid;
}

.row .row_title {
    font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
    text-align: right;
    padding-right: 15px;
    font-size: 35px;
    /* code from Xpert */
    flex-basis: 15%;
    flex-grow: 0;
    /* border-style: solid; */
}

.row .row_content {
    /* code from Xpert */
    flex-basis: 85%;
    flex-grow: 0;
}

#about_content {
    padding-bottom: 10px;
}

#link_tiles {
    display: flex;
    /* code from Xpert */
    flex-wrap: wrap;
    align-content: flex-start;
}

.link_tile {
    /* code from Xpert */
    flex-basis: calc(50% - 10px);
    margin: 5px;
    padding: 5px;
    text-align: center;
    border-style: solid;
}

/* code from Xpert */
.link_tile:first-child {
    flex-basis: 100%;
}

.link_tile:first-child img {
    max-width: 100%;
    max-height: 100%;
}

.link_tile img {
    max-width: 50%;
    height: 75%;
}

footer {
    font-family: var(--font_code);
    text-align: var(--textalign);
    padding: 10px;
    margin: 10px;
}

.row_content li {
    padding: 20px;
}

@media screen and (max-width: 767px) {
    body {
        min-width: 100%;
    }
}