Hi Team,I  have set up new project in AEM, Developed Experience Fragment , Editable Templates and Themes . But I want to write custom CSS to design our header, footer and body content.Please guide me right way to  write CSS for project. 

Code For Reference - public int[] getMomentYearsArr() { int[] years = new int[this.moments.size()]; for (int i = 0; i < this.moments.size(); i++) { OurHistoryMoments moment = this.moments.get(i); years[i] = moment.getMomentYear(); } return years;}