I Built a Simple Interest Calculator with HTML, CSS, and Vanilla JavaScript

I built a simple interest calculator as a small side project to practice handling user inputs and calculation logic using vanilla JavaScript. The goal was to keep it clean, simple, and easy to use. Features Calculates simple interest instantly Clean and minimal UI Responsive layout for mobile Built using HTML, CSS, and vanilla JS Why I built it Many interest calculators online try to do too much at once. I wanted a focused tool that: Does one thing well Is easy to understand Can be reused in small projects Implementation overview HTML for form inputs and structure CSS for spacing, layout, and responsiveness JavaScript for: Interest calculation logic Input validation Real-time result updates No formulas. No math lecture. Live demo & source code Live demo: ( https://yuvronixstudio.github.io/interest-calculator/ ) Source code: ( https://github.com/YuvronixStudio/interest-calculator/ ) What I learned Simpler tools are easier to test and improve Clear input labels reduce user errors Small p