diff --git a/studio-app/src/CloudStudio.jsx b/studio-app/src/CloudStudio.jsx
index f7cf119..2bdacb1 100644
--- a/studio-app/src/CloudStudio.jsx
+++ b/studio-app/src/CloudStudio.jsx
@@ -101,6 +101,7 @@ export function CloudProjects({ onClose, quick = false, initialGrant = null }) {
             <Button
               variant="primary"
               type="submit"
+              className="login-submit"
               disabled={c.busy || c.auth.auth_ready === false}
             >
               {t('account.copy79')}
diff --git a/studio-app/src/HostedSignIn.jsx b/studio-app/src/HostedSignIn.jsx
index 97c8451..4cbaa49 100644
--- a/studio-app/src/HostedSignIn.jsx
+++ b/studio-app/src/HostedSignIn.jsx
@@ -13,7 +13,6 @@ export default function HostedSignIn({ auth }) {
   return (
     <div className="hosted-sign-in">
       <Button
-        variant="primary"
         className="keep-label hosted-sign-in-main"
         onClick={() => window.location.assign(hostedSignInUrl(here(), 'sign-in'))}
       >
diff --git a/studio-app/src/LoginDialog.jsx b/studio-app/src/LoginDialog.jsx
index 2f5096d..e56dc12 100644
--- a/studio-app/src/LoginDialog.jsx
+++ b/studio-app/src/LoginDialog.jsx
@@ -82,7 +82,8 @@ export function Login({ onClose, onDone, title, lead }) {
           )}
           <Button
             type="submit"
-            className="qc-primary"
+            variant="primary"
+            className="qc-primary login-submit"
             disabled={c.busy || !c.auth || c.auth.auth_ready === false}
           >
             {t('workspace.copy5')}
diff --git a/studio-app/src/credits.css b/studio-app/src/credits.css
index e8d18d0..83ec91c 100644
--- a/studio-app/src/credits.css
+++ b/studio-app/src/credits.css
@@ -225,7 +225,17 @@
   }
 }
 
-/* Hosted sign-in (#305): one clear button below the username and password form. */
+/* The password sign-in is the main button; hosted sign-in sits below it (#305). */
+.login-submit {
+  width: 100%;
+  justify-content: center;
+  height: 46px;
+  min-height: 46px;
+  margin-top: 8px;
+  font-size: 15px;
+  font-weight: 600;
+  border-radius: 12px;
+}
 .hosted-sign-in {
   display: flex;
   flex-direction: column;