I’m building an interactive, single-page tool that lets business-focused marketers answer a concise set of 10 questions and see their projected ROI the moment they hit the last one. The flow, styling, and performance all matter as much as the math behind the scenes, so the end result needs to look sharp, load fast, and feel intuitive on any device. I will create a spreasheet for you to script the calculations. Scope and functionality • Industry context: marketing campaigns aimed at businesses. • User inputs: sliders, type inputs, selection boxes. Deliverables • Fully functional HTML/CSS/JS page • Clear, human-readable formulas and variable list inside the code comments • Read-me with simple embed instructions and any build commands Acceptance criteria The calculator must ask exactly 10 questions I provide, respond instantly with no page reloads, and return identical ROI values when tested with the same inputs across Chrome, Safari, and Firefox.