:root {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2a2a2a;
    --text-primary: #e9e9e9;
    --text-secondary: #cccccc;
    --accent-primary: #ba9fd1;
    --border-color: #555;
}

[data-theme="light"] {
    --bg-primary: #f5f5f5;
    --bg-secondary: #dddddd;
    --text-primary: #1c1c1c;
    --text-secondary: #666666;
    --accent-primary: #5a67d8;
    --border-color: #d1d5db;
}

body {
    font-family: 'Optima', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    margin: 0;
    padding: 0;
    font-size: 1.325em;
}

/* Main container - centered fixed width */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 40px 20px 20px 20px;
}

h1, h2, h3 {
    margin-bottom: 1rem;
    font-weight: normal;
}

header h1 {
    text-align: center;
    margin-top: 0.25em;
    margin-bottom: 0;
    font-size: 3em;
    line-height: 1.08;
}

.header-links {
    text-align: center;
    margin-bottom: 0;
    margin-top: 0.65em;
}

.header-links a {
    margin: 0 0.125em;
    text-decoration: none;
}

.header-links a:hover {
    text-decoration: underline;
}

header nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 25px;
}

header nav a {
    font-size: 1em;
    padding: 7px 12px;
    background-color: var(--bg-secondary);
    border-radius: 3px;
    text-decoration: none;
    color: var(--text-primary);
    white-space: nowrap;
}

.header-separator {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 1em 0 1.4em 0;
}

p {
    margin-bottom: 1rem;
}

a {
    color: var(--accent-primary);
    text-decoration: none;
}

a:hover {
    color: var(--text-secondary);
}

footer {
    margin-top: 1.5em;
    padding-top: 1.5em;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1em;
}

.theme-toggle-container {
    display: flex;
    align-items: center;
}

.theme-toggle {
    display: flex;
    cursor: pointer;
}

.theme-option {
    padding: 8px 12px;
    font-size: 0.8em;
    transition: all 0.3s ease;
    user-select: none;
    border: 2px solid transparent;
}

.theme-option.dark {
    background-color: #2a2a2a; /* Dark theme secondary bg */
    color: #e9e9e9; /* Dark theme text */
}

.theme-option.light {
    background-color: #f5f5f5; /* Light theme secondary bg */
    color: #2c2c2c; /* Light theme text */
}

.theme-option.active {
    border-color: var(--accent-primary);
}

details summary {
  list-style: none; /* Remove default triangle */
  cursor: pointer;
  position: relative;
  padding-left: 1.5em;
}

details summary::-webkit-details-marker {
  display: none; /* Remove default triangle in WebKit browsers */
}

details summary::before {
  content: '▲'; /* Plain Unicode triangle */
  position: absolute;
  left: 0.1em;
  top: 0.64em;
  transition: transform 0.2s ease;
  transform: rotate(90deg);
  color: inherit;
  background: none;
  border: none;
  font-size: 0.8em;
}

details[open] summary::before {
  transform: rotate(180deg);
}

details summary h2 {
  display: inline;
  margin: 0;
  font-size: 1.5em;
}

details {
  margin-bottom: 0.65em;
}

.collapsible-content {
  margin-top: 1em;
  padding-left: 1.5em;
}

.spaced-list li {
  margin-bottom: 0.5em;
}

.spaced-list li:last-child {
  margin-bottom: 0; /* Remove margin from the last item */
}