body {
  margin: 0;
  font-family: sans-serif;
  background-color: #111;
  color: #f0f0f0;
}
#container {
  display: flex;
  min-height: 100vh;
  flex-direction: row;
}
#sidebar {
  width: 250px;
  padding: 1rem;
  background-color: #222;
}
.book-toggle {
  background: none;
  color: inherit;
  border: none;
  font-size: 1rem;
  cursor: pointer;
}
.chapter-list {
  margin-left: 1rem;
}
#content {
  flex: 1;
  display: flex;
  flex-direction: column;
}
#reading-pane {
  flex: 1;
  padding: 2rem;
}
#footer {
  background-color: #222;
  color: #ccc;
  padding: 1rem;
  text-align: center;
  margin-top: auto;
}
a {
  color: #81cfff;
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
#toggle-theme {
  position: fixed;
  bottom: 1rem;
  right: 1rem;
  padding: 0.5rem 1rem;
  background-color: #333;
  color: #fff;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  z-index: 1000;
}


.theme-dark {
  background-color: #111;
  color: #f0f0f0;
}

.theme-dark a {
  color: #81cfff;
}

.theme-dark #sidebar {
  background-color: #222;
}

.theme-dark #footer {
  background-color: #222;
  color: #ccc;
}

.theme-light {
  background-color: #fefefe;
  color: #111;
}

.theme-light a {
  color: #007acc;
}

.theme-light #sidebar {
  background-color: #e0e0e0;
}

.theme-light #footer {
  background-color: #ddd;
  color: #222;
}