#hoverBtn:hover{
  background: #0d0;
}
#not_sample button:not(.no-background){
  background: #0d0 !important;
}
#active-sample a:active{
  background: #0f0;
}
#link-sample a:link{
  background: #0f0;
}
#visited-sample a:visited{
  color: #00f !important;
}
input.focusable:focus{
  border: 2px #00a solid !important;
}
#focus_within-sample div{
  padding: 10px;
  border:2px #aaa solid;
}
#focus_within-sample div:focus-within{
  border-color: #f00;
}
input:enabled{
  border: 2px #ddd solid;
}
input:disabled{
  border: 2px #f00 solid;
}
input.checkbox:checked{
  margin:10px;
}