Excel spreadsheet creation, editing, and analysis with capSpire brand styling. This skill should be used when working with Excel files (.xlsx, .xlsm, .csv) for capSpire-branded deliverables. Combines technical Excel workflows (formulas, data analysis, formatting) with capSpire brand guidelines (Franklin Gothic typography, Orange/Charcoal colors). Includes support for formula recalculation, zero-error validation, and industry-standard financial modeling conventions with capSpire visual styling.