Kanaru Sato developed and integrated the Animation.overallProgress API in the mozilla/gecko-dev repository, enabling normalized animation progress reporting with robust edge-case handling and clamping between 0.0 and 1.0. This work included updates to WebIDL definitions and alignment of Web Platform Tests to ensure standards compliance. Kanaru also enabled CommitStyles by default on release channels and streamlined test infrastructure by removing obsolete use counters. In the mdn/browser-compat-data repository, Kanaru updated compatibility data to reflect new Firefox Nightly support. The work demonstrated strong skills in C++ and JavaScript development, API implementation, and cross-repository collaboration to improve animation diagnostics.