What is the best way to implement "movable rectangles"?

Question

Canvas

It is necessary that the user can move rectangles of different sizes in different parts of the screen with the mouse. When you click on a rectangle, it is attached to the mouse pointer and "led" behind it. If a part of a rectangle attached to the mouse pointer touches a part of another rectangle on the screen, then this part of the rectangle is tinted red. How to implement this, with what technology?

Answer 1

https://codepen.io/anon/pen/qwZdMo?editors=1010

Answer 2

here and then track the behavior of the mouse and paint your rectangles in any color

Answer 3

With the help of javascript...By drag and drop a large number of articles. Rectangles to make for example using div-elements. Inside the draggable rectangle, add another red div, which will be made visible when it intersects with others and positioned accordingly within the intersection.