Mastering HTML + CSS: The Complete Guide from Beginner to Advanced - Part 1 [Basics]

The real world is unforgiving. I will thoroughly pass on my optimization expertise through a meticulous mission system, showing you how to design smooth user experiences even in extreme environments where tens of thousands of real-time data points pour in. Go beyond simply writing code and leap forward to become an irreplaceable senior engineer who dissects performance through understanding engine principles.

This is not just a lecture you listen to and forget. This course aims not for "the moment you understand React," but for "the moment you can actually work with React." In every section, you'll complete missions alongside the lectures, solve practice problems yourself, and learn by implementing core concepts like JSX, Virtual DOM, State, and useEffect with your own hands. When you finish the course, you won't just be a beginner who knows React syntax—you'll be a developer who can explain and utilize everything from component design to rendering flow on your own. "Not a class you just listen to, but learning you build through completion." Understand the essence of React and experience the world of declarative UI firsthand.

This course covers the Critical Rendering Path (CRP) process from start to finish, where the browser receives HTML to create the DOM, combines it with the CSSOM, and renders pixels on the screen. Beyond simple DOM manipulation, you'll learn how CSS and JS impact performance, image and font optimization, Lazy Loading, Intersection Observer, virtual lists, and DevTools practice, gaining practical strategies to noticeably improve real web performance.

This course systematically masters intermediate to advanced CSS techniques such as "CSS Position, Transition, Transform, Animation, Flexbox, Grid, and Responsive Web Design," and equips you with skills immediately applicable in real-world projects through various hands-on practice projects.

This course is a full-stack level frontend project course that focuses on implementing Notion from start to finish using Vanilla JavaScript, going beyond simple UI cloning to deeply understand the internal operating principles. You'll implement all the core features of a real note-taking app using vanilla JS, including sidebar tree, nested document creation, auto-save, routing, trash, favorites, search modal, settings modal, theme switching, Export/Import, keyboard shortcuts, responsive layout, drag resize, and more. The goal is to solidly learn browser standard behaviors (event bubbling, DOM tree, local storage, Blob, FileReader, hash routing, etc.) that you must know before frameworks like React and Vue, so you can completely understand "why it works this way" and build the skills to debug effectively.

📌 This course is a curriculum that starts with a strategic AI tic-tac-toe project and completes core object-oriented programming concepts through practical examples. You'll train logic design and AI strategic thinking through game implementation, then directly experience OOP design techniques like inheritance, composition, delegation, and encapsulation through code. This is recommended for those who want to grow beyond syntax into a 'developer who designs' through real projects.

An Express.js journey from beginner to mastery, flowing like water! A backend journey where you learn properly by directly implementing from basic server concepts to completing a CRUD project.

This course goes beyond just using Express.js—you'll implement its internal engine from scratch to truly understand how real servers work. You'll gain hands-on experience growing as a server developer by building all of Express's components from the ground up, including routers, middleware, request-response objects, static file handling, and template rendering.

Through this course, students will broadly learn the basics and advanced concepts of JavaScript, from setting up the development environment to variables, conditional statements, functions, objects, and arrays. Through thorough review with practice exercises and quizzes, they will be able to develop problem-solving skills that can be immediately applied to web and mobile development practices.

No matter how much you study React, Next.js, or Vue, if the code feels abstract and the structure isn't clearly understood, the root cause might be a lack of understanding of DOM. DOM is the foundation of all frontend frameworks and the entity that connects the structure and behavior of web pages. This lecture goes beyond simple selectors or manipulation methods, teaching step-by-step from the very beginning how HTML transforms into DOM objects and how to select, traverse, and manipulate this structure. It is the Part 1 introductory lecture of 'Complete DOM Mastery'. HTML tags are just structure, and JavaScript is just behavior, but DOM is the core that connects the two. If you clearly understand this connection, you'll be able to precisely grasp the true structure and flow within any framework you use.

This course goes beyond simply using Express.js. You will rebuild its internal engine from start to finish, gaining hands-on experience with the real principles of how a server works. By directly creating each component of Express—such as routing, middleware, request–response objects, static file handling, and template rendering—you will grow as a server developer and truly understand how a framework operates at its core.

This course goes beyond simple DOM manipulation, deeply learning how to dynamically compose and react to web UIs within interactions with actual users. It's structured for you to learn by directly implementing common issues encountered in practice, from the essence of event systems, bubbling and capturing, event delegation, real-time UX feedback, to performance optimization using throttle & debounce. Based on an understanding of the DOM tree structure, you will develop the ability to flexibly connect event flow and state changes.

Through this course, students will broadly learn the basics and advanced concepts of JavaScript, from setting up the development environment to variables, conditional statements, functions, objects, and arrays. Through thorough review with practice exercises and quizzes, they will be able to develop problem-solving skills that can be immediately applied to web and mobile development practices.

This course systematically masters intermediate to advanced CSS techniques such as "CSS Position, Transition, Transform, Animation, Flexbox, Grid, and Responsive Web Design," and equips you with skills immediately applicable in real-world projects through various hands-on practice projects.

This is a full-stack series course aimed at developing web and app services at a commercially viable level for beginners, based on real-world experience developing web services in the field. As Part 2 of this series, this course thoroughly covers the latest HTML5, CSS3, and vanilla JavaScript + ES6, considering responsiveness and compatibility among the various frontend technologies available.

The ultimate full-stack course that teaches even beginners about web, server, mobile apps, and machine learning!! If you're not sure where to start with development, I highly recommend this course. It's all done with just Javascript!

Now you can enjoy the easy and fun coding lectures of Young Cody Kim, a current star lecturer who has devoted himself to coding education for over 15 years, targeting elementary school students, high school students in IT software departments, college students in computer science departments, and job seekers who are not majoring in the field, not only offline but also online. With Young Cody Kim, who has produced over 500 front-end, back-end, full-stack, and web developers, your dream of becoming a developer will soon come true!

If you want to build a solid web foundation, come here!

You can learn HTML and CSS quickly by directly cloning and coding the best shopping mall designs posted on Cafe 24. The course is structured so that you can learn the basic theories of HTML + CSS and complete the shopping mall design through direct cloning and apply what you learned in the theory, and solidify the framework of HTML and CSS.

Grab your keyboard and practice, and you'll master the three major web development skills!

This course allows you to learn the major trends in web development by following the overall web technologies required to complete a website.

📌 This course is a curriculum that starts with a strategic AI tic-tac-toe project and completes core object-oriented programming concepts through practical examples. You'll train logic design and AI strategic thinking through game implementation, then directly experience OOP design techniques like inheritance, composition, delegation, and encapsulation through code. This is recommended for those who want to grow beyond syntax into a 'developer who designs' through real projects.

A three-in-one class where you can create web games and learn front-end web development skills! This class has been created to teach you how to create games using JavaScript, CSS, and HTML with your own ideas!

Learning by Doing: 정보처리산업기사 I have prepared everything for passing the 정보처리산업기사 course-evaluation practical exam.

This is a class where you learn concepts through practice, not memorizing concepts. Come even if you feel like vomiting or shaking when you see code in other places. Anyone can do it.

💡 Even non-developers can go from startup MVP to monetized service in just 10 hours with AI! 💰 Development that used to cost tens of millions in outsourcing fees now completely solved for 120,000 won 🎯 Complete 5 real business projects including business card recognition, sentiment analysis, and location analysis 🔥 If you're a planner, marketer, or aspiring entrepreneur, implement ideas without developers ⚡ Start now and acquire lifelong development independence skills!

It is aimed at beginners of html/css, and it builds a solid foundation, and of course, you can learn practical responsive layout creation.

We have created this so that anyone can pass the 2023 version of the Web Design Function Exam Criteria. Let's learn the 5 types and pass quickly!

A current startup CTO will share vibe coding knowledge gained through actual services and various outsourcing projects.

This is the most solid foundation course for beginners who want to learn JavaScript properly. This course will be the starting point for understanding the language called JavaScript, and you can perfectly prepare the basics to become a front-end (Vue, React, Angular) developer and server (Node.js) developer.

This is a specialized practical exam course optimized for the Web Design Development Craftsman (formerly Web Design Craftsman) practical exam content, precisely aligned with the examination standards implemented from 2025.1.1 to 2027.12.31. The Codingworks Web Design Development Craftsman practical exam course, covering HTML+CSS+JQUERY publishing, is different. All instructional videos for perfectly creating all 2026 Web Design Development Craftsman exam types (A, B, C, D, E, F types) are included.

Data can be processed and presented in tabular form, but the most important thing is to present the data in a way that humans can understand at a glance.