/* based from https://www.w3schools.com/css/tryit.asp?filename=trycss_template3 */
/* I also like https://www.w3schools.com/w3css/tryit.asp?filename=tryw3css_templates_start_page&stacked=h */

/* Light mode */
:root {
  --background: #ddd;
  --header-background: #bbb;
  --nav-background: #444;
  --top-background: #fff;
  --color: #000;
  --nav-color: #eee;
  --link-color: #00d;
  --link-visited-color: #608;
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --background: #444;
    --header-background: #777;
    --nav-background: #bbb;
    --top-background: #000;
    --color: #ddd;
    --nav-color: #333;
    --link-color: #aaf;
    --link-visited-color: #a8f;
  }
}

* {
  box-sizing: border-box;
  font-family: Arial, Helvetica, sans-serif;
}

body {
  margin: 0;
  background-color: var(--background);
  font-family: Arial, Helvetica, sans-serif;
}

.topnav {
  overflow: hidden;
  background-color: var(--nav-background);
  color: var(--nav-color);
}

.topnav a {
  float: left;
  display: block;
  text-align: center;
  padding: 10px 10px;
  text-decoration: none;
}

.topnav a:hover {
  background-color: #fff;
  color: #000;
}

.content, .active-nav {
  background-color: var(--background);
  color: var(--color);
}

.content {
  padding: 10px;
}

.top {
  padding: 3px;
  background-color: var(--top-background);
  color: var(--color);
}

.content a:link, .top a:link {
  color: var(--link-color);
}

.content a:visited, .top a:visited {
  color: var(--link-visited-color);
}

ul {
  margin: 0px;
  padding: 0px 0px 0px 20px;
}

li {
  margin: 4px;
}