Worked on the bitmovin-player-ui repository to enhance caption rendering for video playback, focusing on both visibility and stability. Introduced a flex-based layout for the subtitle region, improving FCC caption readability and ensuring that label widths adapt to content. Used SCSS and TypeScript to allow independent visibility of caption window colors and to prevent style bleed between consecutive cues, maintaining consistent styling throughout playback. Addressed rendering stability by moving VTT cue positioning to the wrapper, which prevents collapse and preserves dimensions. These updates improved accessibility and reliability of captions, reflecting a thoughtful approach to UI/UX and front end development.