body {
    background-color: #777;
}

.grid {
    display: grid;
    grid-template-columns: minmax(17em, 25%) 1fr;
}

main, nav, header, footer {
    margin: 20px;
    padding: 1.5em;
    background-color: #fff;
    border: 4px solid #9fefef;
}

main {
    margin-left:10px;
    padding: 1.25em 3em 2em;
}

nav {
    margin-right: 10px;
}
nav ul {
    margin: 0;
    padding: 0;
    list-style-type: none;
    list-style-position: outside;
    line-height: 1.75;
}
nav li ul {
    padding-left: 1em;
}
nav a {
    display: block;
    font-size: 125%;
    color: #000;
    text-decoration: none;
}
nav a.active {
    font-weight: bold;
}

header {
    margin-bottom: 0;
    text-align: center;
}
header a {
    color: #000;
    text-decoration: none;
}
header h1 {
    margin: 0;
}

footer {
    margin-top: 0;
    text-align: center;
}

pre, img {
    max-width: 100%;
    border: 4px solid #9fefef;
}

pre {
    padding: 1em;
    background-color: #ffffea;
}

*:hover {
    border-color: #57a8a8;
}