handle edge case in parsing of units ending with hypen followed by whitespace

src/utils/strings.rs

@@ -32,9 +32,9 @@ fn ident_body_no_interpolation<I: Iterator<Item = Token>>(
             if second.kind == '.' || second.kind.is_ascii_digit() {
                 break;
             }
+
             toks.next();
             text.push('-');
-            text.push(toks.next().unwrap().kind);
         } else if is_name(tok.kind) {
             text.push(toks.next().unwrap().kind);
         } else if tok.kind == '\\' {

tests/subtraction.rs

@@ -209,3 +209,8 @@ test!(
     "a {\n  color: 1/**/-/**/1;\n}\n",
     "a {\n  color: 0;\n}\n"
 );
+test!(
+    no_space_after_first_unit_and_second_float,
+    "a {\n  color: 1em- 0.0em;\n}\n",
+    "a {\n  color: 1em- 0em;\n}\n"
+);