Move styles into a css file

[kakserpom]

This doesn't look pretty in the response body.

<style csr-id="leptos-toaster-toaster" data-hk="0-0-0-24">.leptos-toaster {
  position: fixed;
  width: var(--width);
  box-sizing: border-box;
  padding: 0;
  margin: 0;
  list-style: none;
  outline: none;
  z-index: 999999999;
}
...

Moving it into a css file would make it cacheable.