--- /dev/null
+/* @flow */
+"use strict";
+module.exports = function(atRule /*: postcss$atRule*/) /*: number*/ {
+ // Initial 1 is for the `@`
+ let index = 1 + atRule.name.length;
+ if (atRule.raws.afterName) {
+ index += atRule.raws.afterName.length;
+ }
+ return index;
+};