주기 회기 진단과 로그인 폭 보강

apps/web/e2e/full-sweep-auth.spec.ts

@@ -115,6 +115,39 @@ test.describe("full sweep auth", () => {
     await useRealApi(page);
   });
 
+  // 검증 checklist: auth-login-mobile-scrollport
+  test("login root follows the narrow document scrollport without horizontal overflow", async ({
+    page,
+  }) => {
+    await page.route(ME_PATTERN, async (route) => {
+      await route.fulfill({
+        status: 401,
+        contentType: "application/json",
+        body: JSON.stringify({ detail: "not_authenticated" }),
+      });
+    });
+    await fulfillConfig(page, READY_AUTH_CONFIG);
+    await page.setViewportSize({ width: 390, height: 844 });
+    await page.goto("/login");
+    await expect(page.locator(".lg-root")).toBeVisible();
+    await expectNoHorizontalOverflow(page);
+
+    const widths = await page.evaluate(() => {
+      const documentRoot = document.documentElement;
+      const loginRoot = document.querySelector<HTMLElement>(".lg-root");
+      if (!loginRoot) throw new Error("login root missing");
+      return {
+        documentClientWidth: documentRoot.clientWidth,
+        documentScrollWidth: documentRoot.scrollWidth,
+        loginRight: loginRoot.getBoundingClientRect().right,
+        loginWidth: loginRoot.getBoundingClientRect().width,
+      };
+    });
+    expect(widths.documentScrollWidth).toBeLessThanOrEqual(widths.documentClientWidth + 1);
+    expect(widths.loginRight).toBeLessThanOrEqual(widths.documentClientWidth + 1);
+    expect(widths.loginWidth).toBeLessThanOrEqual(widths.documentClientWidth + 1);
+  });
+
   // 검증 checklist: auth-login-generic-google-button
   test("secondary Google button shows the second allowed domain and starts the same google OAuth flow", async ({
     page,

apps/web/src/components/auth/auth-shell.css

@@ -1,8 +1,8 @@
 .vg-auth-shell {
   position: relative;
   isolation: isolate;
-  inline-size: 100%;
-  max-inline-size: none;
+  inline-size: auto;
+  max-inline-size: 100%;
   min-block-size: 100vh;
   min-block-size: 100dvh;
   overflow-x: clip;

apps/web/src/pages/login/login.css

@@ -1,7 +1,7 @@
 .lg-root {
   min-height: 100dvh;
-  width: 100%;
-  max-width: none;
+  width: auto;
+  max-width: 100%;
   position: relative;
   display: grid;
   grid-template-columns: minmax(0, 1fr) minmax(360px, 500px);