无法在HTML文档中正确显示元素

I just built a simple rock, paper, scissors game, using some javascript and html and, although the game works fine, I did't position the html elements properly apparently, as when I reduce the browser window, the objects don't stay inline. Any suggestion on how to make it so that the page can shrink without breaking lines. As you'll probably be able to tell from my code, I'm a beginner so any kind of advice is well accepted :). Sorry if this is not clear enough but this is not my first language.I just built a simple rock, paper, scissors gam