diff --git a/tests/test_persimmons_ux.py b/tests/test_persimmons_ux.py
new file mode 100644
index 0000000..88d3088
--- /dev/null
+++ b/tests/test_persimmons_ux.py
@@ -0,0 +1,78 @@
+"""Packaged UX invariants; real computed styles/flows in the browser check."""
+import hashlib
+import json
+from pathlib import Path
+import struct
+import unittest
+import zipfile
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+class UxTests(unittest.TestCase):
+    def test_packaged_icons_and_pinned_identity(self):
+        import base64
+        with zipfile.ZipFile(ROOT / 'persimmons/web/extension.zip') as archive:
+            manifest = json.loads(archive.read('persimmons-extension/manifest.json'))
+            digest = hashlib.sha256(base64.b64decode(manifest['key'])).hexdigest()[:32]
+            self.assertEqual(''.join(chr(ord('a') + int(c, 16)) for c in digest),
+                             'kiolgjoohhgdohcafgelhikpgkbmckbg')
+            self.assertEqual(
+                manifest['version'],
+                json.loads((ROOT / 'persimmons-extension/manifest.json').read_text())['version'],
+            )
+            for size in (16, 32, 48, 128):
+                name = manifest['icons'][str(size)]
+                self.assertEqual(manifest['action']['default_icon'][str(size)], name)
+                raw = archive.read('persimmons-extension/' + name)
+                self.assertEqual(raw[:8], b'\x89PNG\r\n\x1a\n')
+                self.assertEqual(struct.unpack('>II', raw[16:24]), (size, size))
+                self.assertEqual(raw, (ROOT / 'persimmons-extension' / name).read_bytes())
+            self.assertFalse(any('/tests/' in name for name in archive.namelist()))
+            self.assertEqual(manifest['externally_connectable'], {'matches': ['https://persimmons.app/*']})
+            self.assertNotIn('content_scripts', manifest)
+            self.assertEqual(manifest['permissions'], ['activeTab', 'scripting', 'storage'])
+            popup = archive.read('persimmons-extension/popup.html').decode()
+            self.assertIn('Save autofilled login', popup)
+            self.assertIn('Lock vault', popup)
+            self.assertIn('Settings', popup)
+            self.assertNotIn('<iframe', popup)
+            self.assertNotIn('human-username', popup)
+            self.assertNotIn('human-password', popup)
+            self.assertNotIn('juice-panel', popup)
+
+    def test_footer_css_and_hero_copy(self):
+        for name in ('tea/web/🍊/index.html', 'persimmons/web/index.html'):
+            html = (ROOT / name).read_text()
+            self.assertIn('🍊 → 💧 → 🤖', html)
+            self.assertIn('>put plainly</span>', html)
+            self.assertNotIn('Persimmons are', html)
+            self.assertNotIn('without paperwork', html)
+            self.assertNotIn('<div class="footerNote">', html)
+        hosted = (ROOT / 'persimmons/web/index.html').read_text()
+        self.assertIn('Master vault', hosted)
+        self.assertIn('id="namedVaults"', hosted)
+        self.assertIn('+ New vault', hosted)
+        self.assertIn('Passwords, PATs &amp; plenty of other useful P’s.', hosted)
+        self.assertNotIn('My vault', hosted)
+        self.assertNotIn('id="refreshAll"', hosted)
+        self.assertIn('id="addCredential"', hosted)
+        self.assertNotIn('Your Persimmons', hosted)
+
+    def test_password_hints_preserve_masking_and_validation(self):
+        from html.parser import HTMLParser
+        class Parser(HTMLParser):
+            def __init__(self):
+                super().__init__()
+                self.nodes = {}
+            def handle_starttag(self, tag, attrs):
+                attrs = dict(attrs)
+                if 'id' in attrs:
+                    self.nodes[attrs['id']] = attrs
+        page = Parser()
+        page.feed((ROOT / 'persimmons/web/signin.html').read_text())
+        for name, value in [('signin', 'on'), ('name', 'username'), ('password', 'current-password')]:
+            self.assertEqual(page.nodes[name]['autocomplete'], value)
+        self.assertEqual(page.nodes['password']['type'], 'password')
+        self.assertEqual(page.nodes['password']['minlength'], '12')
+        self.assertIn('required', page.nodes['password'])