让 Firefox 的 tab 显示序号

tabs-ordinal-group.css

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");

.tabbrowser-tab:not([pinned]){
  min-width: 50px;
}
window {
  counter-reset:section;
}
.tab-stack{
  padding-left: 3px;
}
.tab-stack::before{
  counter-increment:section;
  content:counter(section);
  color: #000;
  line-height: 31px;
  display: block;
}
.tab-content{
  padding-left: 18px;
}