bulma/sass/themes/_index.scss

/* Bulma Themes */
@charset "utf-8";

@use "../utilities/initial-variables" as iv;
@use "../utilities/css-variables" as cv;

@use "light";
@use "dark";
@use "setup";

#{iv.$variables-host} {
  @include light.light-theme;
  @include setup.setup-theme;
}

// prefers-color-scheme: light
@include cv.system-theme($name: "light") {
  @include light.light-theme;
}

// prefers-color-scheme: dark
@include cv.system-theme($name: "dark") {
  @include dark.dark-theme;
}

// :root, [data-theme=light], .theme-light
@include cv.bulma-theme($name: "light") {
  @include light.light-theme;
  @include setup.setup-theme;
}

// [data-theme=dark], .theme-dark
@include cv.bulma-theme($name: "dark") {
  @include dark.dark-theme;
  @include setup.setup-theme;
}