ReliCSS is a tool designed for front-end developers to navigate and modernize legacy CSS code. The author, who has experience as a front-end developer and Design Systems consultant, refers to the process of working with older codebases as "Front-End Archaeology." This approach involves understanding the historical context behind outdated coding practices, such as clearfix hacks and vendor prefixes, which reflect the challenges developers faced in past browser environments. ReliCSS aids in this exploration by scanning CSS for historical artifacts and browser hacks, categorizing them by severity, and providing context and suggestions for modernizing the code. The tool operates entirely in the browser, ensuring that sensitive client code remains secure during analysis. It highlights issues based on severity: high severity includes obsolete hacks for unsupported browsers like IE6/7, medium severity covers older but still functional hacks for IE8-10, and low severity pertains to modern artifacts that can be handled by tools like Autoprefixer. Future enhancements for ReliCSS include drag-and-drop file uploads, URL fetching for live stylesheets, and a Command Line Interface (CLI) to integrate the tool into development workflows. ReliCSS aims to turn the daunting task of refactoring legacy CSS into an educational experience about web history, allowing developers to make informed decisions about what code to keep or discard. By identifying obsolete code, developers can streamline stylesheets and ensure that their projects are built on solid, relevant foundations.