diff --git a/TODO.md b/TODO.md
index b0ceb21..4c1254d 100644
--- a/TODO.md
+++ b/TODO.md
@@ -44,6 +44,16 @@ then continue tagging as milestones land.
 
 # Completed Steps
 
+- 2026-10-08: The browser suites no longer read a screen before the page has
+  shown it ([#502](https://git.eeqj.de/sneak/AutistMask/issues/502)). Their wait
+  for a screen used to pass as soon as the element laid out, which every view
+  does until the page's stylesheet has applied, so an approval test could read
+  the prompt's fields before the page's script had filled them. `visible()` in
+  `tests/e2e/harness.js` and `waitVisible()` in `tests/e2e/firefox/driver.js`
+  now also wait for the page to finish loading and for neither the element nor
+  anything around it to carry the `hidden` class that `showView()` puts on every
+  view but the current one. No caller changed.
+
 - 2026-10-08: Switching the network in Settings now tells open pages
   ([#500](https://git.eeqj.de/sneak/AutistMask/issues/500)). Once the switch is
   saved, Settings asks the background to send `chainChanged` with the new chain
diff --git a/tests/e2e/firefox/driver.js b/tests/e2e/firefox/driver.js
index 0592baa..7aabf7a 100644
--- a/tests/e2e/firefox/driver.js
+++ b/tests/e2e/firefox/driver.js
@@ -279,12 +279,17 @@ class Driver {
 
     // Shown means shown: in the popup a view is switched by toggling a
     // "hidden" class, and an element that is present but collapsed is not
-    // the thing a test means by visible.
+    // the thing a test means by visible. Until the page's stylesheet has
+    // applied that class hides nothing and every view lays out, so the page
+    // must also have finished loading, which it does only after its
+    // stylesheet, and neither the element nor anything enclosing it may
+    // carry the class (https://git.eeqj.de/sneak/AutistMask/issues/502).
     async waitVisible(selector, timeout = DEFAULT_WAIT_MS) {
         return this.waitFor(
             "selector " + selector + " to be visible",
             `const el = document.querySelector(arguments[0]);
-             if (!el) return false;
+             if (document.readyState !== "complete" || !el) return false;
+             if (el.closest(".hidden")) return false;
              const r = el.getBoundingClientRect();
              return r.width > 0 && r.height > 0;`,
             [selector],
diff --git a/tests/e2e/harness.js b/tests/e2e/harness.js
index d2c0a41..4e4047b 100644
--- a/tests/e2e/harness.js
+++ b/tests/e2e/harness.js
@@ -333,8 +333,32 @@ async function launch(routeOpts) {
 
 const PASSWORD = "e2e-harness-password";
 
+// Waits until the page shows `selector`, not only until it lays out. Until the
+// page's stylesheet has applied, the `hidden` class that showView() keeps on
+// every view but the current one hides nothing and every view lays out, so a
+// test could read a screen before the page's script had filled it
+// (https://git.eeqj.de/sneak/AutistMask/issues/502). So the page must also
+// have finished loading, which it does only after its stylesheet, and neither
+// the element nor anything enclosing it may carry `hidden`. Polled on a timer:
+// animation frames are not guaranteed to a window that is not in front.
 async function visible(page, selector, timeout = 15000) {
-    await page.waitForSelector(selector, { state: "visible", timeout });
+    await page
+        .waitForFunction(
+            (sel) => {
+                const el = document.querySelector(sel);
+                if (document.readyState !== "complete" || !el) return false;
+                if (el.closest(".hidden")) return false;
+                const r = el.getBoundingClientRect();
+                return r.width > 0 && r.height > 0;
+            },
+            selector,
+            { polling: 50, timeout },
+        )
+        .catch((e) => {
+            throw new Error(
+                "the page did not show " + selector + ": " + e.message,
+            );
+        });
 }
 
 // An empty WebAssembly module: magic number and version header, no