/* 独立于移动端折叠菜单，让所有页面的右上角都保留外观切换入口。 */
#nav #site-appearance-toggle {
  display: inline-block;
  margin-left: 14px;
  padding: 0;
  border: 0;
  background: transparent;
  font: inherit;
  vertical-align: baseline;
  cursor: pointer;
}

#nav #site-appearance-toggle:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 4px;
}