Excursion Project CSS question

I completed the Excursion project. (spoiler - I have the CSS file for the project solution shown below) No problem. Here is a link to my deployed website:

But when I reviewed the Codecademy solution, the CSS does not include any use of the margin property. I used the margin property to keep the various blocks of text and images separated vertically. If I did not use margin, everything was on top of each other without space separating them. How does the solution keep things apart? Below is the entire CSS file. I don’t see how it spaces items but it does.

body {
background-color: black;
text-align: center;
font-family: “Verdana”, sans-serif;
color: white;
}
.cta {
color: aquamarine;
font-size: 16px;
}
h1 {
font-size: 50px;
font-weight: normal;
}
h2 {
font-size: 42px;
font-weight: 300;
}
p {
font-size: 21px;
color: gray;
}
.footer {
text-align: right;
}