It’s ok, your English is good, but code can be tricky to talk about! Thank you for adding more details. I think the problem makes sense.
Sometimes you can you use margin-top to add more space above.
But it does not work when you scroll!
This is because there is position: fixed in the body:before part, so it will alway stay in the same spot on the screen. Let’s change it to position: absolute instead. ‘Absolute’ lets us tell it how far from the sides we want the edges. We need to tell it to use body for the sides, so we need to add this code:
body {
position: relative;
}
(If you want to learn more about position, fixed, and absolute here here is a post with examples)
Ok, let’s delete min-height: 100% from body:before, because we want it to be shorter than 100%. Now we can control where the top and bottom are! Let’s add top: 70px and bottom: 30px. (Top needs to be big enough to go past the header from the top of the screen).
Does that seem how you wanted? Let me know if it makes sense. 