webstudio/app/shared/css-utils/delete-css-rules-by-breakpoint.ts

import { type Instance, type Breakpoint } from "@webstudio-is/sdk";

export const deleteCssRulesByBreakpoint = (
  instance: Instance,
  breakpointId: Breakpoint["id"]
) => {
  const cssRules = [...instance.cssRules];
  cssRules.forEach((cssRule, index) => {
    if (cssRule.breakpoint === breakpointId) {
      instance.cssRules.splice(index, 1);
    }
  });

  for (const child of instance.children) {
    if (typeof child === "string") continue;
    deleteCssRulesByBreakpoint(child, breakpointId);
  }
};