docs(pytest-plugin[css]): fix card text bleed from Furo theme overrides

why: Furo sets text-indent: -35px (hanging indent for wrapped
signatures) and margin: 0 -4px (negative side margins) on dt elements.
Both cause fixture card content to bleed outside the card border on
the left side.

what:
- Reset text-indent: 0 and margin: 0 on dl.py.fixture > dt
- Add padding-left: 1rem for consistent left spacing
- Use !important on dd margin-left: 0 to override Furo's 32px default

Author: tony

docs/_static/css/custom.css

@@ -469,9 +469,18 @@ dl.py.fixture {
   box-shadow: 0 1px 3px rgba(0,0,0,0.04);
 }
 
+/* Reset Furo's hanging-indent and negative-margin on dt so content
+ * stays within the card border.  Furo sets text-indent: -35px and
+ * margin: 0 -4px for wrapped signatures — both break our flex card. */
+dl.py.fixture > dt {
+  text-indent: 0;
+  margin: 0;
+  padding-left: 1rem;
+}
+
 dl.py.fixture > dd {
   padding: 0.75rem 1rem;
-  margin-left: 0;
+  margin-left: 0 !important;  /* override Furo's dd { margin-left: 32px } */
 }
 
 /* Metadata fields: compact grid that keeps dt/dd pairs together */