This is a bootstrap 4 based component, but any time it can be used without any dependencies and will be absolutely unstyled.
There are two kind of customizations you can do: Every html element has specific css class and you can use that to make some ui corrections.
It will work only if your styles will be added in global styles.scss
file.
Let's highlight specific section and options "1" and "20"
Let's make a vertical tabs
The template uses the bootstrap 4 css classes without any custom styling or overriding.
To customize the ui by yourself you need to use the cssClassPrefix
input and pass the class prefix.
The prefix will be used in css classes generating, for example you passed cssClassPrefix="my-"
as a result the bootstrap class will be transformed from form-group
to my-form-group
.