Testing Tool: Playwright (Chromium Engine)
Test Purpose: Verify that web pages render correctly within viewport boundaries across various device environments
Test Coverage: 9 major viewports (3 mobile, 1 foldable, 3 tablet, 2 desktop)

Measurement Items:
• Actual rendering width of body element
• Overflow pixels beyond viewport width
• Overflow occurrence per viewport

Testing Method:
1. Set browser to each viewport size
2. Wait for network stabilization after page load (6 seconds)
3. Measure document.body.getBoundingClientRect()
4. Calculate overflow pixels by comparing with viewport width

Tested Viewports:
• Mobile: 360×800, 390×844, 414×896
• Foldable: 672×960
• Tablet: 768×1024, 834×1112, 1024×1366
• Desktop: 1280×800, 1440×900

This test takes approximately 30 seconds to 1 minute and helps identify potential horizontal scrollbar issues to improve user experience.