CSS Grid

The Grid. A digital frontier. I tried to picture clusters of information as they moved through the computer. What did they look like? Ships? Motorcycles? Were the circuits like freeways? I kept dreaming of a world I thought I’d never see. And then one day.. I got in. — Tron: Legacy

Introduction to CSS Grid

CSS Grid is a fundamentally new approach to building layouts using CSS.

Keep an eye on the CSS Grid Layout page on caniuse.com to find out which browsers currently support it. At the time of writing, Feb 2018, all major browsers (except IE, which will never have support for it) are already supporting this technology, covering 78% of all users.

CSS Grid is not a competitor to Flexbox. They interoperate and collaborate on complex layouts, because CSS Grid works on 2 dimensions (rows AND columns) while Flexbox works on a single dimension (rows OR columns).

Building layouts for the web has traditionally been a complicated topic.

I won’t dig into the reasons for this complexity, which is a complex topic on its own, but you can think yourself as a very lucky human because nowadays you have 2 very powerful and well supported tools at your disposal:

  • CSS Flexbox
  • CSS Grid

These 2 are the tools to build the Web layouts of the future.

Unless you need to support old browsers like IE8 and IE9, there is no reason to be messing with things like:

  • Table layouts
  • Floats
  • clearfix hacks
  • display: table hacks

We’ll cover Flexbox in a separate guide.

In this guide there’s all you need to know about going from a zero knowledge of CSS Grid to being a proficient user.

The basics

The CSS Grid layout is activated on a container element (which can be a div or any other tag) by setting display: grid.

As with flexbox, you can define some properties on the container, and some properties on each individual item in the grid.

These properties combined will determine the final look of the grid.

The most basic container properties are grid-template-columns and grid-template-rows.

grid-template-columns and grid-template-rows

Those properties define the number of columns and rows in the grid, and they also set the width of each column/row.

The following snippet defines a grid with 4 columns, each 400px wide, and with 3 rows with a 100px height each.

.container {
  display: grid;
  grid-template-columns: 200px 200px 200px 200px;
  grid-template-rows: 300px 300px;
}

A grid with 5 columns and 2 rows

Here’s another example of a grid with 2 columns and 3 rows:

.container {
  display: grid;
  grid-template-columns: 200px 200px;
  grid-template-rows: 100px 100px 100px;
}

A grid with 2 columns and 3 rows

Automatic dimensions

Many times you might have a fixed header size, a fixed footer size, and the main content that is flexible in height, depending on its length. In this case you can use the auto keyword:

.container {
  display: grid;
  grid-template-rows: 100px auto 100px;
}

Different columns and rows dimensions

In the above examples we made regular grids by using the same values for rows and the same values for columns.

You can specify any value for each row/column, to create a lot of different designs:

.container {
  display: grid;
  grid-template-columns: 100px 200px;
  grid-template-rows: 100px 50px;
}

A grid with varying columns and rows dimensions

Another example:

.container {
  display: grid;
  grid-template-columns: 10px 100px;
  grid-template-rows: 100px 10px;
}

A grid with varying columns and rows dimensions

Adding space between the cells

Unless specified, there is no space between the cells.

You can add spacing by using those properties: - grid-column-gap - grid-row-gap

or the shorthand syntax grid-gap.

Example:

.container {
  display: grid;
  grid-template-columns: 100px 200px;
  grid-template-rows: 100px 50px;
  grid-column-gap: 25px;
  grid-row-gap: 25px;
}

A grid with gap between rows and columns

The same layout using the shorthand:

.container {
  display: grid;
  grid-template-columns: 100px 200px;
  grid-template-rows: 100px 50px;
  grid-gap: 25px;
}

Spawning items on multiple columns and/or rows

Every cell item has the option to occupy more than just one box in the row, and expand horizontally or vertically to get more space, while respecting the grid proportions set in the container.

Those are the properties we’ll use for that: - grid-column-start - grid-column-end - grid-row-start - grid-row-end

Example:

.container {
  display: grid;
  grid-template-columns: 200px 200px 200px 200px;
  grid-template-rows: 300px 300px;
}
.item1 {
  grid-column-start: 2;
  grid-column-end: 4;
}
.item6 {
  grid-column-start: 3;
  grid-column-end: 5;
}

Editing the dimensions of some cells

The numbers correspond to the vertical line that separates each column, starting from 1:

The numbers correspond to the vertical line that separates each column

The same principle applies to grid-row-start and grid-row-end, except this time instead of taking more columns, a cell takes more rows.

Shorthand syntax

Those properties have a shorthand syntax provided by: - grid-column - grid-row

The usage is simple, here’s how to replicate the above layout:

.container {
  display: grid;
  grid-template-columns: 200px 200px 200px 200px;
  grid-template-rows: 300px 300px;
}
.item1 {
  grid-column: 2 / 4;
}
.item6 {
  grid-column: 3 / 5;
}

Another approach is to set the starting column/row, and set how many it should occupy using span:

.container {
  display: grid;
  grid-template-columns: 200px 200px 200px 200px;
  grid-template-rows: 300px 300px;
}
.item1 {
  grid-column: 2 / span 2;
}
.item6 {
  grid-column: 3 / span 2;
}

More grid configuration

Using fractions

Specifying the exact width of each column or row is not ideal in every case.

A fraction is a unit of space.

The following example divides a grid into 3 columns with the same width, 1⁄3 of the available space each.

.container {
  grid-template-columns: 1fr 1fr 1fr;
}

Using percentages and rem

You can also use percentages, and mix and match fractions, pixels, rem and percentages:

.container {
  grid-template-columns: 3rem 15% 1fr 2fr
}

Using repeat()

repeat() is a special function that takes a number that indicates the number of times a row/column will be repeated, and the length of each one.

If every column has the same width you can specify the layout using this syntax:

.container {
  grid-template-columns: repeat(4, 100px);
}

This creates 4 columns with the same width.

Or using fractions:

.container {
  grid-template-columns: repeat(4, 1fr);
}

Specify a minimum width for a row

Common use case: Have a sidebar that never collapses more than a certain amount of pixels when you resize the window.

Here’s an example where the sidebar takes 1⁄4 of the screen and never takes less than 200px:

.container {
  grid-template-columns: minmax(200px, 3fr) 9fr;
}

You can also set just a maximum value using the auto keyword:

.container {
  grid-template-columns: minmax(auto, 50%) 9fr;
}

or just a minimum value:

.container {
  grid-template-columns: minmax(100px, auto) 9fr;
}

Positioning elements using grid-template-areas

By default elements are positioned in the grid using their order in the HTML structure.

Using grid-template-areas You can define template areas to move them around in the grid, and also to spawn an item on multiple rows / columns instead of using grid-column.

Here’s an example:

<div class="container">
  <main>
    ...
  </main>
  <aside>
    ...
  </aside>
  <header>
    ...
  </header>
  <footer>
    ...
  </footer>
</div>

.container {
  display: grid;
  grid-template-columns: 200px 200px 200px 200px;
  grid-template-rows: 300px 300px;
  grid-template-areas:
    "header header header header"
    "sidebar main main main"
    "footer footer footer footer";
}
main {
  grid-area: main;
}
aside {
  grid-area: sidebar;
}
header {
  grid-area: header;
}
footer {
  grid-area: footer;
}

Despite their original order, items are placed where grid-template-areas define, depending on the grid-area property associated to them.

Adding empty cells

You can set an empty cell using the dot . instead of an area name in grid-template-areas:

.container {
  display: grid;
  grid-template-columns: 200px 200px 200px 200px;
  grid-template-rows: 300px 300px;
  grid-template-areas:
    ". header header ."
    "sidebar . main main"
    ". footer footer .";
}

Wrapping up

These are the basics of CSS Grid. There are many things I didn’t include in this introduction but I wanted to make it very simple, to start using this new layout system without making it feel overwhelming.