Your site is currently using this code:
@import url('https://fonts.googleapis.com/css2?family=Creepster&display=swap" rel="stylesheet');
body {
font-family: Creepster, cursive;
}
It needs to be this:
@import url('https://fonts.googleapis.com/css2?family=Creepster&display=swap');
body {
font-family: Creepster, cursive;
}
With that said, import statements should only appear at the very top of your css file. Depending on how your theme has been coded, the custom.css file can be appended to other files, which means that your import statement is no longer at the top.
A safer solution would be to use the <link> code. Add this to the <head> area of your theme:
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=Creepster&display=swap" rel="stylesheet">
Then use this in your css:
body {
font-family: 'Creepster', cursive;
}