[6.0.x] Fixed #36850 -- Prevented admin filter sidebar from wrapping below the changelist.

Removed flex-wrap from .changelist-form-container and added min-width to the
main content container to ensure proper layout behavior.
Regression in 6ea331907996a51842da55c1f8d65eea7b367c7d.

Backport of e92d1e3b7858981185e93d717c5727544d66b66e from main.

4 files changed, 27 insertions, 3 deletions

diff --git a/django/contrib/admin/static/admin/css/changelists.css b/django/contrib/admin/static/admin/css/changelists.css
index 60cbaf21eb..0f367f811e 100644
--- a/django/contrib/admin/static/admin/css/changelists.css
+++ b/django/contrib/admin/static/admin/css/changelists.css
@@ -2,7 +2,6 @@
 
 #changelist .changelist-form-container {
     display: flex;
-    flex-wrap: wrap;
     align-items: flex-start;
     width: 100%;
 }
@@ -16,6 +15,7 @@
 }
 
 #changelist .changelist-form-container:has(#changelist-filter) > div {
+    min-width: 0;
     max-width: calc(100% - 270px);
 }
 
diff --git a/docs/releases/6.0.2.txt b/docs/releases/6.0.2.txt
index c708f699bb..c437275f3f 100644
--- a/docs/releases/6.0.2.txt
+++ b/docs/releases/6.0.2.txt
@@ -9,4 +9,7 @@ Django 6.0.2 fixes several bugs in 6.0.1.
 Bugfixes
 ========
 
-* ...
+* Fixed a visual regression in Django 6.0 that caused the admin filter sidebar
+  to wrap below the changelist when filter elements contained long text
+  (:ticket:`36850`).
+
diff --git a/tests/admin_views/models.py b/tests/admin_views/models.py
index 4e2d13efa8..fe127f57d3 100644
--- a/tests/admin_views/models.py
+++ b/tests/admin_views/models.py
@@ -266,7 +266,13 @@ class Person(models.Model):
         (2, "Female"),
     )
     name = models.CharField(max_length=100)
-    gender = models.IntegerField(choices=GENDER_CHOICES)
+    gender = models.IntegerField(
+        choices=GENDER_CHOICES,
+        verbose_name=(
+            "very very very very very very very very very "
+            "loooooooooooooooooooooooooooooooooooooooooong name"
+        ),
+    )
     age = models.IntegerField(default=21)
     alive = models.BooleanField(default=True)
 
diff --git a/tests/admin_views/tests.py b/tests/admin_views/tests.py
index ad37416cbf..e5eba4f466 100644
--- a/tests/admin_views/tests.py
+++ b/tests/admin_views/tests.py
@@ -7059,6 +7059,21 @@ class SeleniumTests(AdminSeleniumTestCase):
         self.assertTrue(show_all.is_displayed())
         self.take_screenshot("pagination")
 
+    @screenshot_cases(["desktop_size", "mobile_size", "rtl", "dark", "high_contrast"])
+    def test_changelist_filter_sidebar_with_long_verbose_fields(self):
+        from selenium.webdriver.common.by import By
+
+        self.admin_login(
+            username="super", password="secret", login_url=reverse("admin:index")
+        )
+        Person.objects.create(name="John", gender=1)
+        self.selenium.get(
+            self.live_server_url + reverse("admin:admin_views_person_changelist")
+        )
+        changelist_filter = self.selenium.find_element(By.ID, "changelist-filter")
+        self.assertTrue(changelist_filter.is_displayed())
+        self.take_screenshot("filter_sidebar")
+
 
 @override_settings(ROOT_URLCONF="admin_views.urls")
 class ReadonlyTest(AdminFieldExtractionMixin, TestCase):