당신의 ePub은 정상입니다

Kobo's rejection of a valid EPUB file containing CSS Level 4 code exposes a fundamental incompatibility between open standards and proprietary implementations. The RMSDK rendering engine powering Kobo remains stuck on 2013-era CSS capabilities, silently failing instead of providing error feedback. This demonstrates that automated compliance tools like epubcheck cannot catch compatibility issues with outdated rendering engines, forcing developers to perform manual device testing despite standards validation.