如何让这个汉堡图像下方的文字从页面左侧流出？

The body text in this page flows from a point not only below the hamburger image but also to the right of it. How can I get it to flow from closer to the left page edge, so that it will look OK on smaller screens? I have tried adjusting margin and padding settings. I am trying to keep this JavaScript-free.The body text in this page flows from a point n