.reading-highlight {
  background-color: rgba(255, 255, 0, 0.4); 
  outline: 2px solid orange;
  box-shadow: 0 0 5px rgba(255, 165, 0, 0.7);
  transition: background-color 0.3s ease, outline 0.3s ease, box-shadow 0.3s ease;
}

.reader-controls {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.control-buttons {
  display: flex;
  justify-content: center;
  gap: 8px; 
}

.reader-control-button {
  background: var(--button-bg, #eee);
  border: none;
  color: var(--popup-text, #333); 
  padding: 8px;
  border-radius: 6px;
  cursor: pointer;
  transition: background var(--transition-speed, 0.2s);
  display: flex;
  align-items: center;
  justify-content: center;
}

.reader-control-button:hover:not(:disabled) {
  background: var(--button-hover, #ddd); 
}

.reader-control-button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  background: var(--disabled-bg, #f5f5f5); 
  color: var(--disabled-color, #aaa); 
}

.reader-settings {
  display: flex;
  flex-direction: column;
}

.reader-setting {
  display: flex;
  align-items: center;
}

.reader-setting label {
  min-width: 50px; 
  font-weight: 500;
  font-size: 0.9rem;
}

.slider {
  flex-grow: 1; 
  cursor: pointer;
}

#speed-value,
#pitch-value {
  min-width: 35px; 
  text-align: right;
  font-size: 0.9rem;
}

.option-section {
  border-bottom: 1px solid #eee;
}

.option-header {
  background: none;
  border: none;
  padding: 10px;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-size: 1rem;
}

.header-content {
  display: flex;
  align-items: center;
  gap: 8px;
}

.chevron-icon {
  transition: transform 0.3s ease;
}

.option-header[aria-expanded="true"] .chevron-icon {
  transform: rotate(180deg);
}

.option-content {
  padding: 10px 15px;
  border-top: 1px solid #eee;
}

.option-content.hidden {
  display: none;
}