Cant align placeholder

[Katerou22]

Cant align placeholder into the center or the right, but can change color of it:

.medium-editor-placeholder:after { text-align: right; color: red; float: right; direction: rtl; }

color will be red, but text-align ? none!

[derakhshanfar]

.medium-editor-placeholder:after {
  right: 0px;
  left: unset;
}