我对 html header 标签和一些 css 有问题，我猜

Question

I'm a very beginner at html and css. I have started learning html and a little bit of css very recently. I try html on androidz as I have no computer yet. In order to do that, I use an apk called trebedit. In my short journey, I've found a huge amount of problem.

I use header (and footer tag also) tag in html. And with css, I tried to give a colored background. But its not fit the screen. (Take a look at the picture, it has been marked) Maybe that's a silly question, but for me, its hard to solve. Can anyone, please, tell me how I can solve this problem?

Answer 1

You must remove the margin of the page elements. Welcome to the world of front end programming

 * { margin: 0; } header { width: 100%; height: 40vh; background: rgb(185, 148, 148) center/cover no-repeat; }

 <header> </header>