Replay.io is developing an innovative way to debug software by recording and replaying its execution, allowing users to share these recordings. However, they encountered an issue with the Library view not rendering correctly in Safari due to quirks mode. Initially, the use of CSS Grid to style HTML tables seemed straightforward, but the layout problems arose because the <table> element was missing the <!DOCTYPE html> declaration, causing Safari to operate in quirks mode and misrender the grid layout. After adding the <!DOCTYPE html> to ensure standards mode, the table layout was corrected, but this change also disrupted other layouts across different browsers, highlighting the complexities and potential pitfalls of web development.