diff --git a/tests/buttons.test.ts b/tests/buttons.test.ts
index d2d2c34..7eb470b 100644
--- a/tests/buttons.test.ts
+++ b/tests/buttons.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { readFileSync } from "node:fs";
+import { existsSync, readdirSync, readFileSync } from "node:fs";
 import path from "node:path";
 import { createElement } from "react";
 import { renderToStaticMarkup } from "react-dom/server";
@@ -34,11 +34,21 @@ describe("SparkleButton disabled", () => {
     expect(body).toContain("var(--tile-3)");
     expect(body).toContain("var(--ink-2)");
     expect(body).toContain("not-allowed");
-    expect(readFileSync(path.resolve(__dirname, "../src/styles/legacy.css"), "utf8")).not.toMatch(/button:disabled\s*\{[^}]*opacity/);
+    for (const f of readdirSync(path.resolve(__dirname, "../src/styles"))) {
+      expect(readFileSync(path.resolve(__dirname, "../src/styles", f), "utf8")).not.toMatch(/(^|[\s,}])button:disabled\s*\{[^}]*opacity/);
+    }
     expect(html(createElement(SparkleButton, { label: "Sign in", disabled: true }))).toContain("disabled");
   });
 });
 
+describe("legacy.css", () => {
+  it("is deleted and no longer imported, and no global button margin rule is left", () => {
+    expect(existsSync(path.resolve(__dirname, "../src/styles/legacy.css"))).toBe(false);
+    expect(readFileSync(path.resolve(__dirname, "../src/app/layout.tsx"), "utf8")).not.toContain("legacy.css");
+    expect(globals).not.toMatch(/(^|[\s,}])button\s*\{[^}]*margin/);
+  });
+});
+
 describe("FlipButton states", () => {
   it("ready: POST plus send icon, flips to PUBLISH with the icon", () => {
     expect(flipLabels("ready")).toEqual({ front: "Post", back: "Publish", icon: true });