--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/github.com/yosssi/gcss/at_rule.go	Sun Jul 23 13:18:53 2023 +0000
@@ -0,0 +1,59 @@
+package gcss
+
+import (
+	"bytes"
+	"io"
+	"strings"
+)
+
+// atRule represents an at-rule of CSS.
+type atRule struct {
+	elementBase
+}
+
+// WriteTo writes the at-rule to the writer.
+func (ar *atRule) WriteTo(w io.Writer) (int64, error) {
+	bf := new(bytes.Buffer)
+
+	bf.WriteString(strings.TrimSpace(ar.ln.s))
+
+	if len(ar.sels) == 0 && len(ar.decs) == 0 && !ar.hasMixinDecs() && !ar.hasMixinSels() {
+		bf.WriteString(semicolon)
+		n, err := w.Write(bf.Bytes())
+		return int64(n), err
+	}
+
+	bf.WriteString(openBrace)
+
+	// Writing to the bytes.Buffer never returns an error.
+	ar.writeDecsTo(bf, nil)
+
+	for _, sel := range ar.sels {
+		// Writing to the bytes.Buffer never returns an error.
+		sel.WriteTo(bf)
+	}
+
+	// Write the mixin's selectors.
+	for _, mi := range ar.mixins {
+		sels, prms := mi.selsParams()
+
+		for _, sl := range sels {
+			sl.parent = ar
+			// Writing to the bytes.Buffer never returns an error.
+			sl.writeTo(bf, prms)
+		}
+	}
+
+	bf.WriteString(closeBrace)
+
+	n, err := w.Write(bf.Bytes())
+
+	return int64(n), err
+}
+
+// newAtRule creates and returns a at-rule.
+func newAtRule(ln *line, parent element) *atRule {
+	return &atRule{
+		elementBase: newElementBase(ln, parent),
+	}
+}