diff --git a/bun.lock b/bun.lock
index 16b5366e..8266229d 100644
--- a/bun.lock
+++ b/bun.lock
@@ -588,7 +588,7 @@
     },
     "packages/styles": {
       "name": "@wrnexus/styles",
-      "version": "0.8.10",
+      "version": "0.8.14",
       "dependencies": {
         "@wrnexus/core": "workspace:*",
         "@wrnexus/plugin": "workspace:*",
diff --git a/packages/styles/package.json b/packages/styles/package.json
index 1d7221c5..cfaf7948 100644
--- a/packages/styles/package.json
+++ b/packages/styles/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/styles",
-  "version": "0.8.13",
+  "version": "0.8.14",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/styles/src/theme.ts b/packages/styles/src/theme.ts
index b226591e..dd4380fc 100644
--- a/packages/styles/src/theme.ts
+++ b/packages/styles/src/theme.ts
@@ -667,7 +667,12 @@ export function renderThemeRuntime(theme: ResolvedTheme): string {
     options=options||{};
     var path=options.path||"/";
     var sameSite=options.sameSite||"Lax";
-    var domain=options.domain?";domain="+options.domain:"";
+    // localhost is not a registrable parent domain. Some browsers reject a
+    // Domain=localhost cookie entirely, so keep it host-only in local dev.
+    var configuredDomain=options.domain;
+    var domain=configuredDomain&&configuredDomain!=="localhost"
+      ?";domain="+configuredDomain
+      :"";
     var secure=options.secure===true||(options.secure!==false&&location.protocol==="https:")?";secure":"";
     return ";path="+path+";samesite="+sameSite+domain+secure;
   }
diff --git a/packages/styles/test/theme-accent.test.ts b/packages/styles/test/theme-accent.test.ts
index 003d1e9c..2cf1cd3f 100644
--- a/packages/styles/test/theme-accent.test.ts
+++ b/packages/styles/test/theme-accent.test.ts
@@ -58,6 +58,7 @@ describe("theme accents", () => {
     expect(runtime).toContain('"domain":"localhost"');
     expect(runtime).toContain("deleteCookie(ACCENT_COOKIE);");
     expect(runtime).toContain("writeCookie(ACCENT_COOKIE,name,ACCENT_COOKIE_OPTIONS)");
+    expect(runtime).toContain('configuredDomain!=="localhost"');
     expect(runtime).not.toContain("setInterval(syncSharedAccent");
   });
 });