Welcome to my CSS for Programmers free online course! If you are a programmer who is looking to explore web development (specifically CSS), and want a clear, no-bs guide to doing so, this guide is for you!

What WON'T this series teach me?

After finishing these articles and completing the challenge projects found at the bottom of the articles, you won't be a CSS master. You won't know every nuance, and you certainly won't be ready to give a talk on the merits of various CSS architectures.

Instead, you'll know how to quickly and reliably create the exact layout you want within CSS, and you can move on with your life.

What's expected of me before I take this course?

  • You should already know basic CSS syntax. If you don't, learn it here.
  • You are willing to learn by doing, and will complete the exercises in the course when they appear.

If the above doesn't apply to you, please look elsewhere.

In this article, you will learn…

  • What the CSS box model is, and why it's important
  • Why CSS should make you think of newspaper articles
  • The old way of layout: Display property (and why you don't need to master it)
  • A primer on the new/better way of layout

The CSS Box Model

The CSS Box Model is just a fancy way of saying that all CSS elements are “boxes”, even if they don't look like them. You need to know the four parts of the CSS Box Model:

![CSS Box Model](/uploads/Group 1.png “CSS Box Model”)

  1. Margin - The space around a box
  2. Border - The box itself - the edge of the element
  3. Padding - the white space between the border and any content
  4. Content - the insides of the box

It's easiest to see this with a real example. Let's look at a paragraph:


Since this block is centered it has a large left and right margin. That's what pushes it to the center:

    div {
    	margin-left: auto;
        margin-right: auto;


The border for this element is that thin black line all around the block

    div {
    	border: 1px solid #OD331;
        /* A border of size 1px, a solid line, 
        and a dark teal color */


The padding is the space between the border line and the paragraph text

    div {
    	padding: 10px;
        /* Padding is 10px on all sides */


The content is the size of the block. In this case, it is dynamically determined by the paragraph element inside of it.

“So, that's great and all, but what do I need to remember about all this?”

It's confusing for beginners to understand the difference between padding and margin, but it's a simple concept once it's broken down. Margin is on the outside of the element, and padding is on the inside.

Try to keep these four terms in mind as we move on, because they will quickly become part of our shared language.

Layout in CSS: Think of Newspaper Articles

With CSS being roughly 25 years old, it's tough for many new developers to understand the context for which it was made, myself included. This creates a disconnect between the syntax and the theory. It's helpful to take a step back and remember that print media, specifically newspapers, was the dominant form of publishing at the time.

Newspaper article from 1994

Looking at this article, doesn't this look similar to what ugly CSS looks like? Do you see the h1 (CSS syntax, this means a large heading) that reads “Undergraduate applications set new record”? What about the black box surrounding the picture and underlying article? Doesn't that look oddly like our CSS Box Model?

The point is, when we are looking at the original layout techniques of CSS, keep this article analogy on hand as it will help with the concepts. Some of these css techniques, such as floats, don't make sense without coming from the perspective of a newspaper article.

The Old-Fashioned Way: The Display Property

WebDevSanity.com is all about teaching you only what you need to know about web dev, so you can reliably use it for your own projects, or work, or whatever. As such, we're only going over the critical aspects of the display property for formatting.

Why are we going over it at all, you may ask? Good question. Here's why I think it's worth discussing even though you should only use it occasionally yourself:

  1. You'll see it on the web. Although you won't be implementing with it too often, it's still around, and it wouldn't be very great if there came a time where you had to at least understand some CSS and it was beyond your comprehension.
  2. You'll still use blocks, even with modern CSS. Even though the rest is used far less frequently, you'll still find yourself relying on good ol’ display: block pretty frequently. As such, you better understand how it works, and you won't have a good-enough understanding unless you understand the other display options that contrast it.

With that out of the way, let's look at the basics of the display property

display: There's only four values that matter

Again, we find ourselves with four values to learn. Keep in mind our newspaper article:

display: block

A block display is made to act like a paragraph. AKA, it is a block of stuff. Block in this case means chunk, like a block of code is a chunk of code, or a block of cheese is a chunk of cheese. For example, the div in the code above was a block.

display: inline

Inline is the second-most important display value out of the four. Inline displays are for when you want something to appear as inside (aka inline) with another element.

A common beginner mistake is to think of “inline” as “next-to”, which is WRONG. Think of “inline” as “inside”.

For example, in newspaper articles you often see that the first letter is far bigger than the rest of the letters in the paragraph. To create this in CSS, I may do something like this:

Notice how the ‘V’ is “inline” with the rest of the paragraph. Since I don't want it to be above the paragraph, I define it as inline.

Look what happens if I define this same “V” as a block:

Notice how the V is now it's own block, it's own “chunk” of the page? That's the difference between block and inline.

Beginners often get confused and consider the two as interchangeable, as if they were items you apply and guess-and-check to see if it fixed your formatting issue. Now, you should understand which of the two to choose for any given element.

display: inline-block

Don't worry, this isn't too complicated. It's an inline element, with the added ability to define a height explicitly. It's rarely used, so I only want to mention it so you've heard of it and have an idea of what it does.

Don't think of it as a hybrid between inline and block. Think of it as inline but you can add height. It's a much better mental model.

display: none

The final display value we'll talk about is display: none. This entirely removes the element from the HTML. Think of this like a delete option. It's useful for when you want something to not exist on mobile devices, for example.

And that's it! Seems pretty simple, right?

So why ignore these tools? This seems pretty straightforward.

For one, there are a host of odd bugs involved in these older layout techniques. Floats, which I have ignored completely for your sake, are notoriously frustrating for new developers, as they have a side-effect of taking the item out of the normal ‘flow’ and into it's own flow. This caused overlap issues that have had hacky solutions for years (optional reading if you are interested).

Instead, here's all you need to know about old-school layout:

  • It uses the ‘float’ and ‘clear’ properties to define how layout should work
    • float: right; will put something on the right
    • float: left; will put something on the left
    • clear: both; will put something below any floated item
  • There was (and still is) a hacky solution called Clearfix, which fixed a major layout issue.
  • Modern solutions ignore float-based layouts in favor of two new strategies: Flexbox and CSS Grid.

Memorizing all of float-layouts is far too buggy for a Sane Web Dev. Unless your work requires a float based layout (browsers from before 2014), you should move on with your life.


  1. CSS Box Model has four parts: Margin, border, padding and content.

What to remember: Remember the four parts, and remember that margin is for space outside of the border, and padding is for space inside the border.

  1. Old-school CSS is like a newspaper, especially regarding float-based layouts

What to remember: Move to modern CSS strategies to more easily create modern web layouts

  1. Display has four important values: block, inline, inline-block, and none.

What to remember: Inline is not the same as “next to”! It means more like “inside of”

  1. Floats and clears were used to figure out where to put things in old-school CSS

What to remember: You need to learn these if you want to support old browsers ( ~0.8% of web users as of publishing this). It's not worth the effort unless it's required by your work, or for some other very specific reason.

Bonus Exercise

Hey listen, you promised yourself at the top that you would try these! The only way to learn programming is to learn by doing, so don't expect that you learn much if you skip this section.

Exercise: Some unexpected behavior

I've tried to create a basic layout: a sidebar on the left, some main content on the right, and a footer below it. However, I've screwed something up in the CSS, and everything is overlapping everything else. I've left some pretty obvious hints in the codepen, see if you can figure it out yourself!

If you're having trouble, here are some hints:

  • Which display property should we use if we want elements to be beside of each other? Is it really display: inline?
  • Old-school CSS required floats to move align things to the left and to the right. Have you used these yet?

Solution is below:

What's Next?

Congrats! Up next, we'll dive into the holy grail of modern CSS layout, Flexbox! You'll learn the essentials of this layout platform, and we'll dive into some real examples of how to do popular website layouts.

Edit: The next article in this series is currently being written! Get notified when it's released by signing up for my newsletter below.

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