HTML Style Guide
Contents:
Styling
Avoid Using the Element style Property
This is generally a bad practice. Instead, favor CSS / SCSS classes. See the SASS docs for more details.
Avoid Using <style> Blocks
In Angular, these styles belong in the template styles, typically <component-name>.component.css or in the case of SASS, <component-name>.component.scss. Styles are then scoped for the current component only, and will not bleed into the rest of the app.