How to add default base styles for specific HTML elements in UnoCSS?

Question

Coming from Tailwind where I could do something like this:

@layer base {
  h1 {
    @apply text-2xl;
  }
}

I'm struggling to find something equivalent in Uno. The only thing I found are Preflights, but they only support raw CSS and not rules/custom rules. How can I add default base styles for specific HTML elements?