:not(:empty) CSS selector is not working?

Question

I\'m having a heck of a time with this particular CSS selector which does not want to work when I add :not(:empty) to it. It seems to work fine with any combina

Answer 1

Another pure CSS solution

.form{
  position:relative;
  display:inline-block;
}
.form input{
  margin-top:10px;
}
.form label{
    position:absolute;
    left:0;
    top:0;
    opacity:0;
    transition:all 1s ease;
}
input:not(:placeholder-shown) + label{
    top:-10px;
    opacity:1;
}

    
    Firstname


    
    Lastname