Nuxt.js lets you define the CSS files/modules/libraries you want to set globally (included in every page).

In case you want to use sass make sure that you have installed node-sass and sass-loader packages. If you didn't just

npm install --save-dev node-sass sass-loader

• Type: Array
  • Items: string

In nuxt.config.js, add the CSS resources:

export default {
  css: [
    // Load a Node.js module directly (here it's a Sass file)
    'bulma',
    // CSS file in the project
    '@/assets/css/main.css',
    // SCSS file in the project
    '@/assets/css/main.scss'
  ]
}

Nuxt.js will automatically guess the file type by its extension and use the appropriate pre-processor loader for webpack. You will still need to install the required loader if you need to use them.