Building a Countdown Timer Web App with Vanilla HTML, CSS, and JavaScript‪.‬

Building a Countdown Timer Web App with Vanilla HTML, CSS, and JavaScript is a hands-on guide for developers who want to create a fully functional countdown timer using core web technologies. Structured in a practical Q&A format, this book walks you through each step of the process, from setting up your project to deploying a working app in the browser.

You’ll learn how to:Structure your HTML for input and displayStyle the app for usability and responsivenessWrite JavaScript logic for countdown timingHandle user input and validate time valuesAdd interactivity with buttons for start, pause, and resetDebug common issues using browser toolsImprove accessibility and user experienceExtend the project with new featuresThis guide is ideal for beginner to intermediate web developers looking to build real projects without frameworks. No libraries, no dependencies, just clean, readable code with a focus on fundamentals.