List of ionic class

Is there some list of class we can use in scss file?
I want to adjust ion-list and I put in global.scss:

.item {
    color: navy;
    font-size: smaller;

.list-header {
    font-weight: bold;
    color: navy

I try also header, io-list-header but the header does not change at all, meanwhile item does.
Which class I have to use? (and for other ion type?)