I want to build a web app using 2 main buttons that will define what content to be displayed:
Buttons CSS, open the webpage content related to CSS tabs w/ 3 levels: LEVEL / 1: CSS / 2: Javascript
LEVEL / 1.1: CSS Beginner / 1.2: CSS Advanced / 1.3: CSS Responsive
LEVEL / 1.1.1: Colors / 1.1.2: BMPH / 1.1.3: Text / 1.1.4: Tables
LEVEL / 1.2.1: Gradients / 1.2.2: Shadows / 1.2.3: Text Effects / 1.2.4: Animations / 1.2.5: Transitions
LEVEL / 1.3.1: Viewport / 1.3.2: Grid View / 1.3.3: Media Queries / 1.3.4: Frameworks
LEVEL / 2.1: JS Functions / 2.2: JS Objects / 2.3: JS Events-HTML DOM
LEVEL / 2.1.1: Parameters / 2.1.2: Invocation / 2.1.3: Call / 2.1.4: Apply / 2.1.5: Closures
LEVEL / 2.2.1: Properties / 2.2.2: Methods / 2.2.3: Constructors / 2.2.4: Prototypes / 2.2.5: ECMAScript 5
LEVEL / 2.3.1: Document / 2.3.2: Elements / 2.3.3: Event Listener / 2.3.4: Navigation / 2.3.5: Nodes