页面似乎停留在一个特定的高度，我不能创建更多的底部空间。

I am trying to clone some website to improve my skills, but I have encounter a problem, the page seems to be stuck in an specific height and when I try to add more html it just disappear (it does not disappear, it's added at the top of the page behind the background image). I really want to know what is causing this and how to fix it without messing with the background image. I am trying to clone some website to improve my