Content Overflow Containment Test
Test Purpose: This test demonstrates that content injected into the editor with problematic CSS
(like position: fixed, position: absolute, etc.) should stay contained within the editor and not affect the page layout.
Expected Behavior: All styled content below should remain within the editor boundaries.
Test 1: Editor with position: fixed content
Test 2: Editor with position: absolute content
Test 3: Editor with very wide content
Test 4: Editor with negative margins
Test 5: Normal content (control test)