CSS Visual Dictionary
Contains visual diagrams for every single CSS property in common use.
To get a good idea of how flex works try flex layout editor on this page.
During my job interview at a Texas software company back in 2017 the team lead has introduced me to the idea that computer scientists (and probably scientists in general) make progress by filling in the gaps.
That idea stuck with me.
This tutorial was created by applying this ideology in preparation for working on the Visual Dictionary — My postmortem to CSS when I decided to take all of the existing 413 CSS properties and visualize them by making diagrams.
But bear with me.
As web and graphic designers the key to CSS grid lies in grasping not the visible parts of layout design but ones that are not.
Let me explain.
Book designers care about margins – essentially an invisible element of book design. It may not seem like much but remove margins — the element that the reader is least aware of— and the whole reading experience turns awkward.
Readers notice lack of margins only when they are absent. Therefore — as a designer (of anything) it is imperative to pay equal attention to the invisible elements of design.
We can always just plug in the content into the layout. Could it be then… that when we design with CSS grid, all we’re doing here to create beautiful layouts is working with an advanced version of book margins? Could be.
Of course CSS grid goes way beyond designing margins in books but the principle of the so-called invisible design remains the same. Things we cannot see are important. In CSS grid this concept is thought of as gaps.
A CSS grid after all is just like taking book margins to the next level. Sort of.
Creating Your First CSS Grid
First… we will need a container and some items.
A CSS grid flow can go in either direction. But by default it’s set to row.
This means that if all other defaults are untouched your items will automatically form a single row where each item inherits its width from the grid’s container element:
CSS Grid Container
Your CSS grid container is a <div> element with: display: grid; and grid-template-columns and/or grid-template-rows properties that define… you guessed it… rows and columns.
Your CSS grid items are <div> elements inside your container. Each item behaves similar to a <td> tag in a <table> but with a lot more flexibility.
All that is just basic HTML.
CSS Grid Template
When making CSS grid layouts we’re essentially defining a template. The grid will take up the empty space on the page, regardless of whether the number of items provided (3 divs in this case) fits into the template area in its entirety:
In this case CSS grid will assume that any new items added to the grid will fall into dashed squares unless other modifications are provided… at which we will look throughout this tutorial.
Let’s start with this really small template to demonstrate some core concepts.
Introducing… Minimalist 2-Column Design
Let’s dig down to the core of CSS grid by using minimum parameters:
One thing you will notice about CSS grid right away is the definition of gaps. This is different from what we’ve seen in any other CSS property before. Gaps are defined numerically starting from the upper left corner of the element.
There are columns+1 gaps between columns & rows+1 gaps between rows.
CSS grid does not have a default padding, border, or margin and all of its items are assumed to be content-box by default. Meaning, content is padded on the inside of the item, not outside like in all other common blocking elements.
That’s one of the best things about CSS grid in general. Finally we have a new layout tool that treats its box model as content-box by default.
Gap size is set individually per row or column by grid-row-gap and grid-column-gap properties or together by grid-gap for short.
Automatic (Implicit) Rows and Columns
CSS grid automatically adjusts position of each item on the grid depending on size and span of surrounding items. And sometimes it makes room for existing items even if column or row values are missing. It will make a best guess.
For example, if you specified only 2 columns with grid-template-columns set to 100px 160px and grid-template-rows set to 25px as shown in next example… but you actually have 4 items in the grid container CSS grid will then automatically decide how the new row should behave… even if it was not explicitly specified by you.
Let’s take a look:
This phenomenon can be also observed when you make items span across multiple rows or columns (similar to rowspan and colspan in a <table>.)
Spanning multiple rows or columns with grid-column-start, grid-column-end, grid-row-start and grid-row-end will produce implicit alignment for any items that fall outside. More on this in just a moment.
An observation: All in all — with default gap values — CSS grid behaves a lot like some type of a <table> that supports implicit items for “leftover” cells:
Although the rules are strikingly similar let’s consider that only an observation… CSS grid is a lot more capable than mere mortal </table>.
Let’s take a look at the rest of CSS grid capabilities to find out the differences.
This property can be used to tell CSS grid to use a specific height for automatic (implicitly created) rows.
Instead of inheriting from grid-template-rows we can tell CSS grid to use a specific height for all implicit rows that fall outside of your definitions.
Bear in mind — of course — you can still set all of the values explicitly yourself:
In a way CSS grid’s grid-auto-flow: column invites Flex-like functionality:
Automatic Column Cell Width
CSS grid is excellent for creating traditional website layouts with two smaller columns on each side. There is an easy way to do this. Simply provide auto as a value to one of the widths in your grid-template-column property:
Your grid will span across the entire width of the container or the browser.
As you can see already CSS grid offers a wide variety of properties to help you get creative with your website or application layout! I really like where this is going so far.
Okay… but what about the gaps…
Dammit, those gaps again.
We already talked about the gaps. Mostly the fact that they cover the space between columns and rows. But we haven’t talked about actually setting them:
I intentionally left the horizontal gaps clasped to their default value of 0.
That’s because I just wanted to provide a few visually descriptive diagrams that demonstrate some potential layouts.
I can already envision a Pinterest-like design with multiple columns using the setup above.
This is the same thing, except with horizontal gaps.
Using grid-gap property we can set gaps in both dimensions at the same time:
And finally… you can set gaps individually for each of the two dimensions.
The next 3 diagrams were created to demonstrate the different possibilities made possible by CSS grid that can be useful in various cases.
Simply use grid-column-gap: 42px and grid-row-gap: 15px
In the example above wide column gaps are used. You can probably use this strategy for crafting image galleries for wide-screen layouts.
I really don’t see much use for the layout setup above. But it’s nice to know that it’s one of the possibilities here.
One thing I was disappointed about was the lack of support for the ability to create varied gap sizing within the same dimension. I think this is the most daunting limitation of CSS grid. And I hope in the future it gets fixed.
The following layout cannot be created using CSS grid:
I’ve been suggested to use columns instead of gaps to achieve this function, every time I bring this up on my Twitter feed.
It might work but I don’t think that in 2018 we should have to descend to what essentially is a CSS hack in a situation for which there isn’t a good reason to exist in the first place.
fr — Fractional Unit — for efficiently sizing the remaining space.
One recent addition to CSS language is the fr unit.
The fr units can be used on things other than CSS grid. But in combination with one they are magical for creating layouts with unknown screen resolution… and still preserve proportion without thinking in percent.
The fr unit is similar to percentage values in CSS (25%, 50%, 100%…etc) except represented by a fractional value (0.25, 0.5, 1.0…)
But although it could be 1fr is not always 100%. The fr unit automatically dissects remaining space. The easiest way to demonstrate this is by following diagrams.
Here is a basic example of using fr units:
This is great news for intuitive designers.
1fr will be 10/1 of 10fr regardless of how much space 10fr takes up.
It’s all relative.
Using 1fr to define 3 columns produces columns of equal width.
Relative to 1fr 0.5fr is exactly half of 1fr.
These values are calculated relative to the parent container.
Can you mix percentage values with 1fr? Of course you can!
The example above demonstrates mixing % units with fr. The results are always intuitive and produce the effect you would expect.
Using fr units and increasing column gaps at the same time will produce the following result. I just wanted to include this here to demonstrate that fr units will be affected by gaps too:
And just to be complete you can use fr units to create something like this:
Although I don’t know where you would require such a dinosauric layout it clearly demonstrates how fr units can affect both rows and columns.
CSS grid allows the use of repeat property value.
The repeat property takes two values: times to repeat and what to repeat.
At its basic this is how it works:
Here grid-template-columns are provided two different sets of value to produce the same effect. Obviously repeat saves a lot of hassle here.
Final verdict: to save yourself from redundancy in cases where your grid must contain repetitive dimension values use repeat as a remedy.
The repeat property can be sandwiched between other values:
grid-template-columns: 50px repeat(3, 15px 30px) 50px;
In this example we repeat a section of two columns 15px 30px for 3 times in a row. I mean in a column. Ahh! You know what I mean.
Using CSS grid spans you allow your items to stretch across multiple rows or columns. This is a lot like rowspan and colspan in a <table>.
We will create a grid using repeat to avoid redundant values. But it could have been created without it — anyway, let’s make it our specimen for this section.
When we add grid-column: span 3 to item #4 a somewhat unexpected effect has occurred:
Using grid-column span 3 to take up 3 columns. However, CSS grid makes a decision to remove some of the items, because the “spanned” item cannot fit into suggested area.
In CSS grids spans can also be used to cover multiple rows. And if it so happened that the column is now greater in height than the height of the grid itself the CSS grid adapt itself to this:
You can also span across multiple rows and columns at the same time. I created this other minimalistic example just to quickly demonstrate limitations, even though in most cases this will probably not happen:
Pay attention to how CSS grid adapts to the items around spans that cover multiple rows and columns. All of the items still remain in the grid but intuitively wrap around other spanned items.
When I tried to break the layout with a large span I ended up with the following case that demonstrates the key limitations of CSS grid:
But it’s still a lot like a <table>. See my other CSS grid vs table tutorial where I show you the frightening similarities.
However… there is a solution.
Start and End
So far we used CSS grid spans to create multi-column and multi-row items that occupy a ton of space. But… CSS grid has another much more elegant solution to solve the same problem.
The grid-row-start and grid-row-end properties can be used to define the starting and ending point of an item on the grid Likewise, their column equivalents are grid-column-start and grid-column-end. The are also two short-hand properties: grid-row: 1/2 and grid-column: 1/2.
These work an a slightly different way than spans.
With -start and -end properties, you can physically move your item to another location in the grid. Let’s take a look at this minimalist example:
Interestingly, designers of CSS grid have decided for the direction of the span vector to be insignificant. The span is still created within the specified area regardless of whether starting or ending points are provided in reverse order:
Let’s consider this 6 x 4 CSS grid. If you explicitly specify an items’s column end position that goes outside the number of specified columns (>=7) you will experience this wonky effect:
In this case CSS grid will adapt the resulting layout of your grid to what you see in the example above. It’s usually a good idea to design your layouts by being mindful of grid’s boundaries to avoid these types of scenarios.
Start and End’s Shorthand
You can use the shorthand properties grid-row and grid-column to same effect as above using / to separate values. Except instead of providing an end value, it takes width or height of the span:
What if we need to reach the absolute maximum boundary of the grid?
Use -1 to extend a column (or row) all the way to the end of CSS grid’s size when number of columns or rows is unknown. But be mindful of any implicit items (16, 17) slipping away from the bottom of the grid:
Then I tried to do the same with rows, but the results were more chaotic, depending on which combinations of values I provided. I know there are other ways of using / but for the sake of clarity I want to keep things simple.
When I was experimenting with rows to do the same thing, it seems like 4 in grid-column: 2/4 had to be changed to 2/6… but only if grid-row: 2/-1 was specified.
That puzzled me a bit. But I guess I still have a lot of learning to do on how /-separated values work.
What I found out though is that juggling around values here produced results that cannot be easily documented using visual diagrams.
Well, at least we get the basic idea here. You can extend either column or row all the way to the maximum boundary using -1. How one affects the other takes a bit of practice to figure out in some specific cases.
We can expand on this a bit. CSS grid has a secondary coordinate system, so to speak. And because it doesn’t matter which direction you use to make cross-column and cross-row spans you can use negative values:
As you can see CSS grid coordinate system is pretty flexible.
Content Align Within CSS Grid Items
Let’s say you’ve gone to the great lengths mastering CSS grid item spans. You crossed the seas of implicitly generated rows and columns. Now you’re curious to see what else is in store for you.
Good news for you then.
As a web designer, I’ve for a long time craved multi-directional float. I wanted to be able to float in the middle and on any corner of the container.
This functionality is only limited to CSS grids’ align-self and justify-self and does not appear to work on any other HTML element. If your entire site’s layout is built using a CSS grid then it solves a lot of issues associated with corner and center element placement.
VERTICAL: Use align-self: end to align the content to the bottom of the item. Likewise, align-self: start will make sure content sticks to the upper border.
HORIZONTAL: Use justify-self: start (or end) to justify your content left or right. In combination with align-self you can achieve placement depicted on any of the above examples.
Just to finalize this discussion here is how align-self affects a slightly more complex situation — one we’ve taken a look at before in this tutorial:
You can use values start, center and end.
Note, however there aren’t top and bottom values for align-self.
Another property that does the same thing but horizontally is justify-self:
You can use start|left or end|right values interchangeably here.
Template areas provide a way to refer to an isolated part of your grid by a predefined name. This name cannot include spaces. Use - instead.
Each set of row names is enclosed in double quotes. You can further separate these sets of row names either by a line break or by space to create columns as shown in the example below.
Although only 5 items are present template are names can logistically occupy places not yet filled with items:
Similar principle to specifying row and column size is followed here to name all of the areas in the grid. Just separate them by space or tab.
This syntax simply allows us to intuitively name our template areas.
But things get a lot more convenient when you start combining areas with the same name across multiple containers. Here I named 3 items in the left column Left and 3 items in the right column Right. CSS grid template areas automatically combined them to occupy the same space by name.
It’s important to make sure that areas consist of items aligned into larger rectangle areas. Doing Tetris blocks here will not work. Straying from the rule of always keeping your areas rectangular is likely to break the CSS grid and/or produce unpredictable outcome.
Naming Grid Lines
Working with numbers (and negative numbers) can become redundant over time especially when dealing with complex grids. You can name grid lines with whatever you want using [name] brackets right before size value.
To name the first grid line you can: grid-template-column: [left] 100px Likewise for rows it is: grid-template-row: [top] 100px
You can name multiple grid lines. The  brackets are inserted at an intuitive place in the set. Exactly where the grid line (a.k.a. gap) would appear:
grid-template-columns: [left] 5px 5px [middle] 5px 5px [right]
Now you can use the names left, middle and right to refer to your grid lines when creating columns and rows that need to reach that area:
Naming gap lines creates a more meaningful experience. It’s a lot better to think of the middle line as center (or middle) instead of 4. This tutorial covered almost everything there is to CSS grid using visual diagrams.
In conclusion… remember…
The music is not in the notes, but in the silence between — Wolfgang Amadeus Mozart
This seems to be true of CSS grid also. And so many other things!
I spent the entire last 3 weeks drawing diagrams representing pretty much every single thing you can possibly do with CSS grid. And you’ve just looked at (and hopefully learned from) them.
Of course I assume the possibility I missed one or two things. And I will be glad for anyone in the community to point it out so I can improve this article.
Thanks for your time reading — aaand I will see you in my next Medium tutorial. I am currently working on visual diagrams for the entire webkit set.
CSS — Visual Dictionary
Click here for the discount page.
What is this? A CSS desk reference to remind you of many common CSS properties with the accompanying visual diagrams explaining how they work — in a similar way as demonstrated in this tutorial.
Interested? Grab your copy here. (offered at a discount to my current Medium readers)