There is really cool method for nested numbered lists:

<style>
ol {
    list-style-type: none;
    counter-reset: item var(--start-value, 0);
}

ol > li:before {
    content: counters(item, ".") ". ";
    counter-increment: item
}
</style>

Is there something similar for formatting a nested numbered list as a degree?

1. some text

1<sup>1</sup>. some text
1<sup>2</sup>. some text
1<sup>3</sup>. some text

2. some text
2<sup>1</sup>. some text

3. some text

“content” rule in css cant handle html-tags