theme.info.yml

https://www.drupal.org/docs/8/theming-drupal-8/defining-a-theme-with-an-infoyml-file
https://www.weebpal.com/blog/how-create-drupal-8-theme-scratch

name: Fluffiness
type: theme
description: A cuddly theme that offers extra fluffiness.
core: 8.x
libraries:
  - fluffiness/global-styling
stylesheets-remove:
  -'@classy/css/components/tabs.css'
  - core/assets/vendor/normalize-css/normalize.css
regions:
  header: Header
  content: Content  # the content region is required
  sidebar_first: 'Sidebar first'
  footer: Footer

• name (required)

  • The name of your theme, which will show up in the administration/appearance D8 admin

• description (optional yet recommended)

  • What you want to describe about your theme, which also appear in the Administration/Appearance

• version (optional)

  • The version of your theme. It will show behind the theme name.

• type (required)

  • Notify Drupal about the type of extension. E.g. Theme, Module, or Profile.

• core (required)

  • The major version of Drupal core that is supported

• base theme (optional yet recommended)

  • Indicate what base theme your custom theme will inherit. If not defined, Drupal will use “Stable” as your base theme.

• region (optional)

  • Define the regions of the theme where you place your blocks. If not declaring any regions in the .info.yml file, Drupal will use the default regions of the core. Keep in mind that if you define the regions even just one, default regions are no longer applied. “content” region is required to exist if you define regions in the info file

Example

name: Fluffiness

type: theme

description: A cuddly theme that offers extra fluffiness.

core: 8.x

libraries:

• fluffiness/global-styling

stylesheets-remove:

• '@classy/css/components/tabs.css'
• core/assets/vendor/normalize-css/normalize.css

regions:
header: Header
content: Content # the content region irequired
sidebar_first: 'Sidebar first'
footer: Footer