Now the basic setup is ready for SASS and also while running ionic serve you will add all custom styling and SASS related changes in all different files for each of the components or pages. Let's start with changing one of the color variables by default present in the variable.scss file:
/* To customize the look and feel of Ionic, you can override the variables For example, you might change some of the default colors:
You can now use this color key as a property to many components, such as buttons:
<button facebook>Share on Facebook</button>
SASS is really powerful and it speeds up the CSS development process. It acts as a Swiss army knife for CSS, where we can do multiple things with minimum lines of code and then with just some changes we can easily change the entire look and feel of the application. There are so many examples of how we can use SASS, but as we are more into Ionic development, I recommend going through some good SASS documentation and Ionic 3 theming docs once so that detailed information will be provided.