This text delves into HTML and CSS organically. Each chapter focuses on a variety of HTML and CSS elements, together, in a context of practical and functional examples. Instead of dissecting each feature myopically, this book jumps into the “thick of it” and considers each HTML and CSS element in combination with other elements that are needed to make a given case work. For example, in chapter 2, explanations on how to build tooltips are provided, and topics, such as CSS selectors, absolute and relative positioning, text effects, CSS functions, and transformations, are covered. The key philosophical principle guiding this series is that software systems are synergistic combinations of diverse technologies; and, successful learning of these technologies is best facilitated via detailed and, importantly, immersive examples. Building functional mini-applications requires the fluent use of a broad range of HTML and CSS vocabularies. The cases presented in this series fully capture the richness of HTML and CSS languages.