Deep Fundamentals
Understanding HTML and CSS
Master semantic HTML and modern CSS for accessible, well-structured websites
Build Web Interfaces That Last
HTML and CSS are the foundation of everything you build for the web. Every framework, every library, every fancy tool eventually compiles down to HTML and CSS. If you don’t understand these fundamentals deeply, you’re building your entire career on shaky ground.
I’ve taught over 360,000 students how to build web applications, and here’s what I’ve learned: the developers who struggle most aren’t struggling because they don’t know enough tricks. They struggle because their mental models are broken.
You’ve probably felt this. You follow a tutorial, it works, you feel good. Then your boss asks you to build something slightly different, and you’re lost. You don’t know why your CSS cascade isn’t behaving. You don’t understand why your layout breaks. You Google frantically, try random Stack Overflow solutions, and hope something sticks.
I’m going to be direct with you: that’s not a sustainable way to build a career.
Stop Building Divs and Spans Everywhere
Here’s a hard truth: most developers are building inaccessible websites without even knowing it. They reach for <div> and <span> for everything because that’s what they’ve seen in tutorials. But HTML gives you semantic elements for a reason. When you use proper semantic HTML, you’re not just writing cleaner code. You’re making your sites accessible to people using screen readers, keyboard navigation, and assistive technologies. You’re improving SEO. You’re writing markup that actually means something.
I’ll teach you to break this habit and author HTML the way it was designed to be written.
Go to the Source
This course is different because we go to the source. Not just my interpretation, not just best practices someone made up. We read the actual HTML and CSS specifications together. We look at how browser rendering engines actually work, under the hood. We understand the problems these technologies were designed to solve, so when you face new problems, you’ll know how to think about them.
For Beginners: Start Right
You’ll build accurate mental models from day one. You won’t develop the bad habits that take years to unlearn. You’ll understand semantic HTML and how it makes your sites accessible to everyone. You’ll learn the cascade, inheritance, and specificity in a way that actually makes sense. When you finish this course, you won’t just know how to build layouts. You’ll understand why CSS works the way it does.
For Experienced Developers: Reset Your Mental Models
This course will reset the mental models you’ve been fighting against. You know that feeling when CSS doesn’t behave the way you expect? That’s not CSS being weird. That’s a gap in understanding. We’ll fill those gaps. You’ll learn to read the specs with confidence, which means you’ll be able to teach yourself every new CSS feature that comes along, from Container Queries to :has to CSS Nesting. You’ll stop fighting your tools and start wielding them with precision.
What You’ll Master
We’ll build modern, responsive interfaces using Flexbox, Grid, and cutting-edge CSS features. You’ll learn mobile-first responsive design. You’ll even learn how to prompt AI tools to generate better HTML and CSS, because you’ll understand what quality output actually looks like.
This isn’t about memorizing properties. It’s about understanding systems. The students who take this approach, who commit to truly understanding rather than just imitating, they’re the ones who become senior developers, tech leads, and architects. They’re the ones who solve problems instead of creating them.
Your career deserves a solid foundation. Let me help you build it.
Curriculum
What Students Are Saying
Hear from students who have taken this course
I am a professional developer with many years of backend and frontend experience and this course has been invaluable in clearing out bad HTML habits, as well as my general antagonism toward CSS...but Tony makes sense of the HTML/CSS universe!
I highly recommend this course, and if you haven't taken it yet, his Javascript course is also absolutely fantastic! If you are a professional developer, even if you have many years of HTML and CSS under your belt (as did I), do yourself a favor and take this course. I have already made many semantic changes (for the better) to a major site that I am responsible for leading and managing, and it has made a huge difference.
I initially purchased this course for the CSS portion and almost skipped the HTML section entirely (because everyone knows HTML, right?) but boy am I glad that I went through all of the HTML as well. I had no idea I was missing so much! Thanks, Tony, for another GREAT COURSE!
John Grow
Very deep explanation of the core principals. Well structured and easy to comprehend. You get the whole picture of HTML/CSS right from the beginning so you can understand why you should do things in a certain way.
Christian Janz
A word to any new student or to-be, Tony never disappoints. From class #1, he will make sure that the course's objective is to make each student understand the subject from scratch and build from zero, holding your hand at every new concept or technical big word. Going more specifically in this course, I started my career more than years ago, and this is the type of study that brings you back to basics and provides quality classes, making you feel like you are starting web development again I can assure you a new understanding of web building and good practices for a subject much underappreciated.
It will make your everyday work better by knowing how to make good sites/apps with the correct basic understanding and building better products in the future of your career. Tony is the teacher every programmer needs to listen to at least one time in their lives.
Nicolas Omar Gonzalez Passerino
This course and this man that teaching the course I just don't know how to describe them, there's no words can describe the ability that this course will give you, the course will teach you how to understand things under the hood, how to write html and css that will make everyone happy if you are a client, a browser user agent, another developer or human being user.
Hassan Ghorab
To so sum it up in one word: INCREDIBLE! There's really good info on how things are done, but even more importantly, in my opinion, the course explains WHY things work the way they do. I've taken other HTML and CSS courses online and as part of my college curriculum, but none of them have explained either topic even half as well as this course does. I'd seen others mention Tony as a good instructor, and after taking this course, I can see why. I wish Tony could teach everything!
