:root {
  --bg: #000000;
  --fg: #f0f0f0;
  --accent: #5A7863;
  --max: 900px;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
}

body {
  font-family: serif;
  max-width: var(--max);
  margin: 1rem auto;
  padding: 0 1rem;
  line-height: 1.6;
}

/* Theme toggle */
html.dark {
  --bg: #ffffff;
  --fg: #000000;
}

/* Basic layout */
header, footer {
  margin-bottom: 1rem;
}

hr {
  border: none;
  border-top: 1px solid var(--fg);
  margin: 1rem 0;
}

nav a {
  margin-right: 1rem;
  color: var(--accent);
  text-decoration: none;
}

nav a:hover {
  text-decoration: underline;
}

/* Content links */
a {
  color: var(--accent);
  text-decoration: underline;
}

/* Headings */
h1, h2, h3 {
  font-weight: normal;
  color: var(--accent);
}

/* Lists */
ul, ol {
  margin: 0.5rem 0 0.5rem 1.5rem;
}

/* Code blocks */
pre {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.12);
  padding: 0.75rem;
  overflow-x: auto;
}

/* Inline code */
code {
  background: rgba(255,255,255,0.05);
  padding: 0.1rem 0.25rem;
}

/* Theme toggle button */
.theme-toggle {
  display: inline-block;
  margin-right: 1rem;
}

.theme-toggle button {
  background: transparent;
  border: 1px solid var(--fg);
  color: var(--fg);
  padding: 0.25rem 0.5rem;
  cursor: pointer;
  font-family: inherit;
}

.theme-toggle button:hover {
  background: var(--fg);
  color: var(--bg);
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.theme-btn {
  background: transparent;
  border: 1px solid var(--fg);
  color: var(--fg);
  padding: 0.2rem 0.5rem;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.9rem;
}

.theme-btn:hover {
  background: var(--fg);
  color: var(--bg);
}