properly escape backslashes

src/utils.rs

@@ -189,7 +189,11 @@ pub(crate) fn parse_quoted_string<I: Iterator<Item = Token>>(
                 continue;
             }
             TokenKind::Symbol(Symbol::BackSlash) if !is_escaped => is_escaped = true,
-            TokenKind::Symbol(Symbol::BackSlash) => s.push('\\'),
+            TokenKind::Symbol(Symbol::BackSlash) => {
+                is_escaped = false;
+                s.push('\\');
+                continue;
+            },
             TokenKind::Interpolation if !is_escaped => {
                 found_interpolation = true;
                 s.push_str(

tests/values.rs

@@ -350,3 +350,8 @@ test!(
     "a {\n  color: \"f\"foo;\n}\n",
     "a {\n  color: \"f\" foo;\n}\n"
 );
+test!(
+    escaped_backslash,
+    "a {\n  color: \"\\\\\";\n}\n",
+    "a {\n  color: \"\\\";\n}\n"
+);