Data Types, If-Statements and Operators, Functions,
Switch Statements, Loops, the DOM, Template Literals,
Destructuring, Exceptions, Object Oriented Programming,
Classes, Callbacks and Promises, the Fetch API, Rest and
Spread, Object Properties, Maps and Sets, and Build Tools.

HTML: Doctypes, head, body, paragraph, div, header, footer,
main, lists, images, links.
CSS: Selectors, rules, properties, padding, margin, borders,
background color, font size, text alignment, inheritance,
type selectors, direct descendants, classes, IDs, specicity,
advanced selectors, mobile responsiveness (responsive
web design).