如何正确对齐div元素?

The body of my html document consists of 3 elements, a button, a form, and a canvas. I want the button and the form to be right aligned and the canvas to stay left aligned. The problem is when I try to align the first two elements, they no longer follow each other and instead are next to each other horizontally?, heres the code I have so far, I want the form to follow directly after the button on the right with no space in between.The body of my html document consists of 3 elem