Prettier 1.14.3
Playground link

--parser scss

Input:

Label {
	font-size: 24;
}

Output:

label {
  font-size: 24;
}

Expected behavior:

Label {
  font-size: 24;
}

I am using prettier on a NativeScript project, which uses an Xml markup with some tag names similar to html but with uppercase names (like Label and Button). CSS is largely case-insensitive, so the styles still apply properly even with the incorrect lowercase tag names output by prettier, but it sure looks inconsistent when looking at the markup and the styles together.