:root {
  --bg: #222;
  --fg: #ddd;
  --muted: #999;

  --accent1: #cc3;
  /* yellow */
  --accent2: #3cc;
  /* cyan */
  --accent3: #c3c;
  /* magenta */

  --code-bg: #111;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  max-width: 700px;
  margin: 2rem auto;
  padding: 1rem;
  background: var(--bg);
  color: var(--fg);
  font-family:
    system-ui,
    -apple-system,
    Segoe UI,
    Roboto,
    sans-serif;
  line-height: 1.6;
}

body > aside {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  padding: 6rem 1.5rem;
  background: rgba(0, 0, 0, 0.8);
}

header,
footer {
  text-align: center;
}

iframe {
  border-radius: 0.5rem;
  width: 100%;
  margin: 0 auto;
  max-width: 650px;
  height: 100%;
  background: var(--fg);
}

details > summary {
  cursor: pointer;
  font-size: larger;
  font-family: Georgia, serif;
  color: var(--accent3);
}

details {
  border-bottom: solid 1px var(--accent3);
}

/* Headings */
h1,
h2,
h3,
h4 {
  margin-top: 2rem;
  line-height: 1.25em;
  color: var(--fg);
}

h1 {
  text-align: center;
}

h2 {
  border-top: 1px solid var(--accent3);
  padding-top: 1rem;
  margin-top: 4rem;
}

/* Text */
p {
  margin: 1rem 0;
}

a {
  cursor: pointer;
  color: var(--accent2);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

a.run {
  position: absolute;
  bottom: 0.2rem;
  right: 0.5rem;
}

a.run::after {
  content: "Run ▶︎";
}

a.close {
  position: absolute;
  top: 2rem;
  right: 3rem;
  color: var(--accent2);
}

a.close::after {
  content: "Close";
}

blockquote {
  border-left: 3px solid var(--accent3);
  padding-left: 1rem;
  color: var(--muted);
  margin: 1rem 0;
}

/* Lists */
ul,
ol {
  padding-left: 1.5rem;
}

li {
  margin: 0.3rem 0;
}

ul {
  list-style-type: none;
}

li::before {
  content: "•";
  display: inline-block;
  width: 1rem;
  margin-left: -1rem;
}

/* Inline code */
code {
  background: var(--code-bg);
  padding: 0.2em 0.4em;
  border-radius: 4px;
  font-family: "ui-monospace", SFMono-Regular, Menlo, monospace;
  font-size: 0.9em;
  color: var(--accent1);
}

/* Code blocks */
pre {
  position: relative;
  background: var(--code-bg);
  padding: 1rem;
  overflow-x: auto;
  border-radius: 6px;
  border: 1px solid var(--accent3);
}

pre code {
  background: none;
  padding: 0;
  color: var(--fg);
}

/* Tables (GitHub markdown support) */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
}

th,
td {
  border: 1px solid var(--accent3);
  padding: 0.5rem;
  text-align: left;
}

th {
  background: #2a2a2a;
}

/* Horizontal rule */
hr {
  border: none;
  border-top: 1px solid var(--accent3);
  margin: 2rem 0;
}

nav {
  margin: 2rem 0;
}

nav ul {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: center;
  padding: 0;
  margin: 0;
  text-align: left;
}

nav .hamburger {
  display: none;
}

nav.fixed {
  margin: 0;
  position: fixed;
  top: 0;
  right: 0;
  width: fit-content;
  min-width: 3rem;
  background: var(--code-bg);
  padding: 0.5rem;
  border: 1px solid var(--accent3);
  z-index: 1000;
}

nav.fixed ul {
  display: none;
}

nav.fixed.show ul {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding: 1rem;
}

nav.fixed .hamburger {
  display: block;
}