diff --git a/cli/src/commands/app/bundle.ts b/cli/src/commands/app/bundle.ts
index 0ebbdaa076..286e878cfb 100644
--- a/cli/src/commands/app/bundle.ts
+++ b/cli/src/commands/app/bundle.ts
@@ -191,7 +191,14 @@ function createSveltePlugin(appDir: string): any {
 
         // Convert Svelte syntax to JavaScript
         try {
-          const { js, warnings } = svelte.compile(source, { filename });
+          // The raw-app editor's in-browser bundler compiles with
+          // `css: "injected"`, so this must too, or the same app renders
+          // styled there and unstyled once the CLI builds it: Svelte's default
+          // ("external") hands the <style> back on a `css` field nothing emits.
+          const { js, warnings } = svelte.compile(source, {
+            filename,
+            css: "injected",
+          });
           const contents = js.code + `//# sourceMappingURL=` + js.map.toUrl();
           return { contents, warnings: warnings.map(convertMessage) };
         } catch (e: any) {
diff --git a/cli/test/raw_app_svelte_module_unit.test.ts b/cli/test/raw_app_svelte_plugin_unit.test.ts
similarity index 76%
rename from cli/test/raw_app_svelte_module_unit.test.ts
rename to cli/test/raw_app_svelte_plugin_unit.test.ts
index 736e048100..5946465a95 100644
--- a/cli/test/raw_app_svelte_module_unit.test.ts
+++ b/cli/test/raw_app_svelte_plugin_unit.test.ts
@@ -1,8 +1,5 @@
 /**
- * `lib.svelte.ts` / `lib.svelte.js` modules are plain modules that may use
- * runes. They need `svelte.compileModule`; without it esbuild happily bundles
- * `$state(...)` as an ordinary call and the app dies at runtime with
- * "ReferenceError: $state is not defined".
+ * The svelte esbuild plugin, driven through `createBundle`.
  */
 
 import { afterAll, beforeAll, describe, expect, test } from "bun:test";
@@ -59,6 +56,12 @@ afterAll(() => {
   fs.rmSync(tempDir, { recursive: true, force: true });
 });
 
+/**
+ * `lib.svelte.ts` / `lib.svelte.js` modules are plain modules that may use
+ * runes. They need `svelte.compileModule`; without it esbuild happily bundles
+ * `$state(...)` as an ordinary call and the app dies at runtime with
+ * "ReferenceError: $state is not defined".
+ */
 describe("svelte plugin: .svelte.ts modules", () => {
   test("compiles runes in a TypeScript rune module and the bundle runs", async () => {
     writeApp({
@@ -116,3 +119,36 @@ bump();
     expect((globalThis as any).__counterResult).toBe(2);
   });
 });
+
+/**
+ * Svelte's default `css: "external"` hands a component's <style> back on a
+ * field the plugin never emits, so the markup keeps its `svelte-<hash>` class
+ * while the rule matching it disappears — no build error, just an app that
+ * renders unstyled from the CLI and styled in the editor.
+ */
+describe("svelte plugin: component styles", () => {
+  test("a <style> block reaches the bundle under the class its markup carries", async () => {
+    writeApp({
+      "Styled.svelte": `<main>
+  <h1>Hello</h1>
+</main>
+
+<style>
+  h1 {
+    font-size: 1.5rem;
+  }
+</style>
+`,
+      "styles_entry.ts": `import Styled from './Styled.svelte';
+export default Styled;
+`,
+    });
+
+    const js = await bundle("styles_entry.ts");
+
+    const scopeClass = js.match(/<h1 class="(svelte-[a-z0-9]+)"/)?.[1];
+    expect(scopeClass).toBeDefined();
+    expect(js).toContain(`h1.${scopeClass}`);
+    expect(js).toContain("font-size");
+  });
+});
diff --git a/cli/test/setup.ts b/cli/test/setup.ts
index 7f27240220..7c0bfd7a74 100644
--- a/cli/test/setup.ts
+++ b/cli/test/setup.ts
@@ -10,6 +10,12 @@
  *    bear the startup cost inside their per-test timeout window.
  */
 
+// esbuild's node API pins the cwd it spawns its service with to process.cwd() at
+// module import, and test files chdir into temp dirs they later delete. Import it
+// here, from a cwd that outlives the run, or the first file to bundle pins the
+// service to a directory that stops existing and every later build fails ENOENT.
+import "esbuild";
+
 if (process.env["UNIT_ONLY"]) {
   // Nothing to do — unit tests don't need backend setup
 } else {