.dark-mode h1,
.dark-mode h2,
.dark-mode h3,
.dark-mode h4 {
  color: #fff;
}

.dark-mode a {
  color: #909090;
}

.dark-mode {
  background-color: #333;
  color: #fff;
}

.dark-mode footer {
  background-color: #444;
  color: #fff;
  padding: 10px;
}

.dark-mode nav ul li a {
  background-color: #555;
  border: 2px solid #666;
  color: #fff;
}

.dark-mode .selected-item {
  background-color: #777;
}

.dark-mode nav ul li a:hover {
  background-color: #444;
}

.dark-mode nav ul li a.active {
  background-color: #444;
  font-weight: bold;
  box-shadow: 0 0 10px #fff;
}

.dark-mode .download-link {
  background-color: #ddd;
  color: #000;
}

.dark-mode .download-link:hover {
  background-color: #aaa;
}

.dark-mode-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  display: flex;
  align-items: center;
}

.dark-mode .timeline-line {
  background-color: #ddd;
}

.dark-mode .timeline-line.dotted {
  border-left: 2px dotted #ddd;
  background: none;
}

.dark-mode .year-marker {
  color: #ddd;
}

.dark-mode .timeline-event {
  box-shadow: 0 0 5px #ddd;
}

.dark-mode .timeline-heading h3 {
  box-shadow: 0 0 10px #ddd;
}

.dark-mode .timeline-event::after {
  color: #ddd;
}

.dark-mode .timeline-event::before {
  color: #ddd;
}

.dark-mode .detail-box {
  background-color: #555;
  color: #ddd;
}