Add a .css theorem class in marp(it)

Question

I would like to incorporate the following CSS classes in my marp slides (I work within vscode with the vscode extension):

.theorem {
display: block;
font-style: italic;
}
.theorem:before {
content: "Theorem. ";
font-weight: bold;
font-style: normal;
}
.theorem[text]:before {
content: "Theorem (" attr(text) ") ";
}

Answer 1

style: |
     .theorem {
display: block;
font-style: italic;
}
.theorem:before {
content: "Theorem. ";
font-weight: bold;
font-style: normal;
}
.theorem[text]:before {
content: "Theorem (" attr(text) ") ";
}
paginate: true

And inside your file you have to add class on block item https://michelf.ca/projects/php-markdown/extra/#spe-attr