Implement the general functions of calculator. In the desktop - The width of calculator will fix in 480px. - But when the browser width is smaller than 768px, the width of calculator will fix in 360px. - We can drag and drop the calculator to everywhere. In the mobile - Calculator will fix below, and the height is 50% of the browser. - We can not drag and drop but we can scroll it. We can open calculator with clicking button and close it with clicking outside. https://github.com/tpps88206/michael-calculator