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The Complete CSS Grid Tutorial

The Complete CSS Grid Tutorial

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This is influenced by CSS grid tutorial on Semicolon.

This comprehensive guide to the CSS grid is a long tutorial (avg. 14 minutes.) It's like a full course so get your pen and paper ready!

You’re probably familiar with the box model for regular elements.

Here’s bird’s eye view for the CSS Grid model:

image.png

(CSS Grid Anatomy is composed of the primary container which can be just your <div> element that has a margin, border and padding.)

To make a parent CSS grid container out of any element use display: grid:

.grid {
    display: grid;
}

Then just apply it to your markup:

<main class = "grid">
    <section>1</section>
    <section>2</section>
    <section>3</section>
</main>

You can use <div> or any blocking element. Sometimes your grid element will be <main>, <article> or <section> or any of the elements from HTML5 set.

How Do You Define CSS Grid Items?

Grid’s items are simply the children elements nested inside the parent container.

They can often represent a header, sidebar, footer or similar layout components, depending on your application design.

Later in this tutorial when we get to Template Areas we'll see how multiple cells can represent those types of layout components.

Let's imitate the grid shown in the header screenshot above

  • In this case there are 3 items defined by <section> element.
  • The third item will be stretched horizontally across 2 cells.
  • (Note: We'll need additional CSS template code below to accomplish that.)
  • Lines help you organize gaps. First line is line 1 (It's a non 0-index system.)
  • Lines can be also counted backwards using negative coordinate system.
  • (But you will rarely have to use them. Just know they exist.)
  • The grid shown in above screenshot is 5 by 4 cells in dimension.
  • It can be defined by following CSS code:
.grid {

/* This is our CSS grid parent container */
  display: grid;

/* 5 cols (each 100px in width) */
  grid-template-columns: 100px 100px 100px 100px 100px;

/* 4 rows (each 100px in height) */
  grid-template-rows:    100px 100px 100px 100px;
}
  • Use grid-template-columns to define number and width of columns.
  • Use grid-template-rows to define number and height of rows.
  • Number of rows and columns is assumed implicitly by number of children present. The grid template layout definition is only a placeholder for items. If no children are present, no cells will be created (even if the column/row templates are defined.)
  • In between each cell there is a line and an optional gap.
  • Rows and columns between the lines are referred to as grid’s tracks.
  • There are always [cell + 1] lines per dimension.
  • Therefore 5 columns will have 6 lines whereas 4 rows will have 5 lines.
  • In the following example there are 7 columns and only 1 row:

image.png

(Some of the first things you will notice about the CSS grid behavior.)

The first important thing you will notice about CSS grid is that outer lines are not affected by gap size. Only inner lines. We will take a deeper dive into this a bit later in this tutorial when we look at fractional (fr) units.

The CSS grid is bi-directional. Its items can flow either horizontally (column) or vertically (row). Set the value with grid-auto-flow property.

It works kind of like Flex:

image.png

Using grid-auto-flow: row or grid-auto-flow: column to determine flow direction of the grid’s items.

Think about the grid in this abstract way:

image.png

Okay — so we got the basic idea of how it works.

The creative part comes in when you are faced with the problem of actually juggling the item placements to create a sensible application layout. CSS Grid offers several properties to accomplish just that. We’ll take a look at them in the next section in this tutorial in just a moment.

Let’s cement our knowledge so far by looking at these examples:

image.png

I only used two <div> elements for the items. Hence, the grid above.

Implicit and Explicit Content Placement

But what happens if we add one more item to the list?

image.png

Adding item 3 to the same layout will automatically extend it (blue item.)

This new spacing is created automatically by copying values from first row.

Let’s add Item 4 shall we?

image.png

And again our CSS grid has made a decision to stretch Item 4 across the remaining space on second row.

This is because grid-template-rows specified enough space only for 1 row. The rest are automatic.

Placement of blue items is not explicitly specified by you. This is implicit (automatic) placement. They kind of just fall into that space.

Explicit Content Placement

This is just what you would expect from grid cells if you set custom values for all items on the list:

image.png

Basically you can gain control over the space on all consecutive rows by adding more values to grid-template-rows property. Notice the items are no longer implicit here. You defined them to be exact. (25px 75px)

Automatic Spacing

CSS grid offers a few properties to automatically stretch its cells across variable / unknown amount of space. Here are the key examples for both column and row auto flow cases:

image.png

The bottom example demonstrates the usage of auto keyword. This just means that cell will stretch to fill up however much space is left in parent container after it has already been populated by explicitly placed items.

CSS Grid Gaps

Talking about CSS grid you can’t escape talking about gaps. Gaps are the horizontal and vertical spaces between grid cells.

Gaps are controlled using grid-column-gap and grid-row-gap properties:

image.png

You can use varying gaps in both dimensions. perhaps this can be useful for creating video or image galleries:

image.png

Gaps across dimensions (columns and rows) can differ in size. But gap size is specified once for all gaps in the grid in a given dimension. As you can see here — gaps of varying size within the same dimension are not allowed:

image.png

I really wish varying size gaps were possible. I can see how this can actually be useful. Some suggest to use empty tracks in order to achieve a similar effect.

FR units (Fractional Units)

Fractional (fr) units are unique to CSS grid.

A fractional unit allocates relative to all other elements in the parent:

image.png

The behavior changes but 1fr remains the same regardless whenever different values are used. Fractional units work similar to % values but they are easier and more intuitive to divide space with:

image.png

(Behavior of fractional units (fr unit) changes based on all values provided in either dimension.)

In this example only column-wise behavior is shown for simplicity’s sake. But it works the same for rows too. Simply use grid-template-rows property.

Fractional Units And Their Relationship To Gaps

Space defined using fractional units changes based on gaps. The same 1fr within the same parent will shrink to a smaller size when gaps are added:

image.png

(Here we added gaps to cells specified using fr units.)

As you can see, this gives you a pretty good set of properties to space content basically in any way you wish without worrying about pixel values.

These new dynamics render pixel-perfect design as a thing of the past. We will now think about layout design using the intuitive approach!

Finally, to give you a better idea of using non-whole fractional units here is a fun grid I created. You can specify them using floating point numbers too:

image.png

Content Placement

We’ve just dissected the CSS grid anatomy. Hopefully you get a better idea of how CSS grid structures content. But now we need to get creative and actually place some items inside it. How it’s done might modify default behavior of the CSS grid. We’ll explore how this happens in this section.

To arrange your items across cells or template areas on the grid you will refer to them by lines between cells. Not <table>-like spans.

CSS grid does allow using spans for determining width and height of the content area (in cell space) just like tables. We’ll explore that in just a bit. But you still can and probably should specify the starting cell using line numbers or named lines (more on this in a bit.) This depends on your preference..

As far as content placement across multiple cells goes the most obvious and tempting thing is cell spanning.

Cell Content Spanning

You can span an item across multiple cells.

Important: Spanning changes location of the surrounding items.

Spanning using grid-column and grid-row

Using grid-column and grid-row properties on the item element itself:

image.png

The blue items changed location after making Item 7 span across multiple cells. And orange items were bumped down a row.

There is also another way of doing the same thing…

Spanning using grid-column-start…

…grid-column-end, grid-row-start and grid-row-end you can specify actual starting and ending points across which you want to span cell content.

I removed the items past 15 (orange ones) because we no longer need them:

image.png

(Type these properties directly into the item you wish to be affected by them.)

Stretching content across column and row lines works in both directions.

min-content and max-content

The values min-content and max-content are supplied to grid-template-columns or grid-template-rows properties just like any other size-related value (for example px, 1fr, etc.)

image.png

Let’s take a look at this specimen. It is our starting point. We’ll change things around a bit to see how min/max values affect cells.

Let’s see what type of results will be produced if we switch one of the columns to min-content and max-content:

image.png

With one-word text there’s no difference between the results observed whether we use min-content or max-content. Here it is because hello is a single word. Its min and max values are exactly the same.

But things get interesting with more complex text. The following example will demonstrate the basic idea behind min-content and max-content:

image.png

Here min-content used longest word in the sentence (stranger) as base width.

When using max-content the entire text string with spaces filled the space.

But what happens if we apply min-content or max-content to all cells?

image.png

I noticed that by default the text was centered whenever I used min-content on it although text-align: center was not set on the item.

Images and max-content

I placed the image of this blue rose into the cell.

And just as expected, the grid expanded to allocate enough space:

image.png

When I explicitly set the width of the image to 50% just to see what happens CSS Grid still kept cell width to 100% of the image but displayed image at 50% width (as expected) and auto-centered it horizontally within the cell.

Both text and images (or any content) will be automatically centered within CSS Grid’s cells by default.

Content Positioning

Up until this point we’ve talked about Grid’s structure in general.

In the next section, we’ll take a look at how to achieve “multi-directional” float inside cells. We won’t be using float property here of course.

Multi-directional 360° float

I don’t think CSS Grid specification calls it that. But, indeed it is possible to create exactly that… a 360-degree floating behavior.

This works on both inline and blocking elements! And I think this is my favorite feature from the entire CSS Grid’s set of abilities.

image.png

All 9 combinations are possible using align-self and justify-self properties.

They are explained below.

Align Self (align-self)

This property helps you position content vertically.

image.png

  • Use align-self: start to align content to the upper edge of the cell.
  • Use align-self: center to align content to its vertical middle.
  • Use align-self: end to align content to the bottom of the cell.

Justify Self (justify-self)

This property helps you position content horizontally.

image.png

  • Use justify-self: start to align content to the left edge of the cell.
  • Use justify-self: center to align content to its horizontal middle.
  • Use justify-self: end to align content to the right edge of the cell.

You can use any of the 9 justify-self x align-self combinations to align anything anywhere aka multi-directional float.

Template Areas

Template areas are defined using grid-template-areas property.

image.png

Note, template areas for each row are enclosed in double quotes.

Each column is separated by space.

In this example I simply explained how to name ares. To take real advantage of template areas you need to categorize rectangular blocks of cells by same name.

Tetris block-shaped areas are not allowed.

You can only use rectangles:

image.png

Here Left is one area spanning 3 cells down. CSS Grid automatically treats it as a single block. The same goes for Right. In this simple example I created two columns. But you get the idea. Block out larger areas by naming them.

To place an item into that area simply add grid-area: TemplateName. In this case it is grid-area: Left or grid-area: Right.

Template area names cannot use spaces. I used dashes here.

Practical Example of CSS Grid Template Areas

We now understand how to block out rectangular areas. Let’s take a look at a potentially real-world scenario. Here I’ll demonstrate a very basic layout.

I blocked a very simple website layout with two sidebars, a header and footer areas. The main area is in the center occupying 3 x 2 cell space:

image.png

(Each color-coded area is named template area. You only need 1 HTML item element to create a grid cell for that entire area. )

Template Area Source Code

Here is an example of grid-template-areas (template areas) which is a source code recreation of what you've just seen in the screenshot above!

<head>
  <style type = "text/css">
    #grid { grid-template-areas:
      'x y y y y'
      'x center center center w'
      'x center center center w'
      'x z z z z';
    }
  </style>
</head>
<body>
  <div id = "grid">
    <div style = "grid-area: x">Left</div>
    <div style = "grid-area: y">Header</div>
    <div style = "grid-area: x">Footer</div>
    <div style = "grid-area: w">Right</div>
    <div style = "grid-area: center">Main</div>
  </div>
</body>

We only need 5 items here. Add any more and they would be pushed outside of the main grid area into implicit cells.

Just make sure to always keep your areas square or rectangular.

Naming Lines

Instead of always referring to lines by their number, you can also name them. This way they will be easy to remember for stretching items across multiple cells. Numbers can get tedious!

Below is a representation of what it looks like:

image.png

(You can also name lines (gaps) with grid-template-column or grid-template-rows property!)

Use square brackets to name your lines. Then use these names when specifying the length your items need to span across using / slash.

In Conclusion

CSS Grid is a comprehensive subject. Hence, this is not a complete CSS Grid tutorial on how to build actual CSS layouts. I simply used one example for each separate part as a starting point for someone new to the grid.

Hopefully information here was insightful and inspired interest in building websites using CSS Grid. CSS Grid isn’t just an HTML element. It’s an entire system for building responsive websites and web applications.

Its properties and values describe the conglomerate of techniques learned from over a decade building websites using common HTML tags.

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