In this exercise, you'll practice creating columns.

## Starting HTML & CSS

You don't need to touch the HTML file, but it's important to understand the structure.

The markup consists of a `div` with an ID of `container`, which contains three cards.

```html
<div id="container">
  
  
  
</div>
```

In the CSS file, there are some predefined styles that create the cards. These are marked as the "NO TOUCHING ZONE".

![screenshot](https://res.cloudinary.com/dwppkb069/image/upload/v1684351359/tutorials/images-03.1_Exercise1_Intro.mp4/031_exercise1_intro_4_00-17400-into-this--three-equally-sized-300-pixel-columns_rj7fdv.png)

## Challenge

Your task is to write the CSS below the indicated line to create a three-column layout, with each column 300 pixels wide.

Take your time to practice this exercise, and when you're ready, you can check the solution.

Practice defining columns by converting a single-column layout into an evenly sized three-column grid.

## Creating a Three Column Layout with CSS Grid

The first thing to do is turn on grid for the container by setting its display property to grid:

```css
#container {
  display: grid;
}
```

After doing this, you might notice a small difference in the layout, but it will still appear as a single column.

Next, use the `grid-template-columns` property to set the size of each column. We want three columns of 300 pixels each:

```css
.container {
  display: grid;
  grid-template-columns: 300px 300px 300px;
}
```

Now, you should have a three column layout with evenly sized columns. Each column is hard-coded at 300 pixels, as the challenge asked for:

![screenshot exercise](https://res.cloudinary.com/dwppkb069/image/upload/v1684351360/tutorials/images-03.2_Exercise1_Solution.mp4/032_exercise1_solution_5_00-58340-but-that-was-what-the-exercise-asked-for_mdk2ka.png)

Implement a Three-Column Layout

[0:00] To create our three-column layout here, the first thing we have to do is turn on grid. Currently we have our container, but it is not a grid container, so I need to set display to grid.

[0:12] Once I do that, I guess we see a little difference but not a whole lot. Because it's still a single column, I now need to make it a three-column layout.

[0:20] I want to each column to be 300 pixels, so we use grid-template-columns, and then 300 pixels for my first column, 300 pixels for the second, and 300 pixels for the third column.

[0:33] There we are. We have a three-column layout, evenly sized. Each one happens to be hard-coded at 300 pixels, but that was what the exercise asked for.

Converting a Single-Column Layout

[0:00] All right. It's time for an exercise. We're going to get some practice creating columns. What I want you to do is take what currently looks like this, a single-column layout, no grid involved whatsoever, and turn it into this, three equally sized, 300-pixel columns.

[0:17] If you look at the HTML file, it tells you, you don't need to touch anything in here, and please don't touch anything. Do what you want, but it's not going to help the exercise at all. You can at least look at the markup. There's a div with the ID of container, there's three cards in there. As you can see, we have three cards.

[0:34] In the CSS file, there's a good amount of styling that you don't need to touch either. It says, START OF THE NO TOUCHING ZONE, down to END OF THE NO TOUCHING ZONE. These are just styles there to create the cards, but then ALL YOUR CODE GOES DOWN BELOW THIS LINE.

[0:50] I'd like you to write the code to style the container so that we end up with a three-column layout, each column, 300 pixels. Give it a shot and I'll be back with the solution.

Creating CSS layouts that behave as expected no matter the viewport size used to be a frustrating, time-consuming experience.
But thanks to CSS Grid, these headaches are a thing of the past!
Through a series of concise lectures and hands-on exercises, this comprehensive tutorial will guide you through everything you need to know about creating responsive layouts for all of your web applications.

## CSS Grid Basics

Dive right into CSS Grid! You'll learn how to enable grid, define basic layouts, and use DevTools overlays to help plan and debug grid lines and areas.

## Units and Utilities

Pixels are precise, but can lead to annoying calculations. Luckily CSS Grid supports alternatives like percentages and fractional units that can be combined to create more complex layouts without having to do math. Useful shorthand properties and helpful functions are also introduced.
## Positioning Elements by Lines
Learn to take a more specific approach to creating layouts by specifying the lines where elements should be placed.

## Grid Areas

When the layout you're implementing is too complex for specifying lines, grid areas are the way to go. In this section you'll learn to visualize your layout as you create named areas, including support for empty spaces.

## The Implicit Grid

You've seen a few ways to explicitly define layouts. Now it's time to look behind the scenes at the implicit grid. Understanding this behavior allows you to change the default placement algorithm and support dynamic layouts.

## Creating Responsive Grids

Up until now the layouts we've created have been meant for larger computer screens. In this section you'll practice creating grid layouts that seamlessly adjust to different viewport sizes with help from media queries and useful CSS Grid functions.

## Building an Example Layout

To wrap up the CSS Grid tutorial, follow along as a common layout is built step-by-step following the "mobile first" approach.


Learn how to activate CSS Grid for a container element and the difference between 'display: grid' and 'display: inline-grid'.

Enabling CSS Grid

The grid developer tools available in modern browsers allow you to visually inspect your CSS grids with overlays and track lines.

Visualize CSS Grid with DevTools

The `grid-template-columns` property is used to define column widths within a grid container in CSS Grid.

Define CSS Grid Columns with grid-template-columns

The `grid-template-rows` property is used to define rows within a CSS Grid container.

Define CSS Grid Rows with grid-template-rows

Practice changing the appearance of a layout without changing its markup.

Specifying Row Heights

Adjust Row Heights in an Existing Layout

The `grid-template-columns` and `grid-template-rows` properties can both be added to create more complex layouts.

Combining Rows and Columns to Create Layouts

Defining Row and Column Sizes

Practice Creating a Two-Column, Three-Row Layout

Colorful boxes help demonstrate CSS Grid concepts, but using paragraph text provides a more realistic example.

Paragraph Layout with CSS Grid

CSS Grid Basics

Using Percentage Units

Percentages are easier than pixels, but even they can reach a limit. Fractional units provide a flexible approach to layouts.

Simplify Grid Layouts with Fraction Units

Create a three-column layout with equal-sized columns and two rows. The top row should be twice as large as the bottom row. The layout should be responsive.


Define a Three-Column, Two-Row Grid

Implement a Layout with Fractional Units

You aren't stuck with just one unit when defining a grid. Mixing units allows for more complex layouts.

Mixing Fractions and Pixels

CSS Grid's `repeat` function is a time saving way to define your layouts.

Simplify Layout Definitions with repeat

Practice using fractional units and the `repeat` function by implementing a checkerboard layout.

Use Fractional Units and repeat to Define a Layout 

Implement a Checkerboard Layout

So far we've been defining rows and columns manually. The `grid-template` shorthand allows us to define both at once.

Save Time with the grid-template Shorthand

CSS Grid supports adding gaps between rows and columns, allowing you to put visual space between elements.

Adding Gaps between Rows and Columns

Implement a 3x7 Grid Layout

Practice Using Shorthand Properties and Gaps

Units and Utilities

Items in a grid can be positioned based on column and row lines in the grid.

Positioning with Grid Lines

Using the `grid-column-start` property allows you to set where items in the grid should begin.

Specify the Column Start Position 

In this exercise, you'll practice moving an element using line numbers.

Moving an Element to a New Column

Setting an Element's Column Position

Just as you can specify the column start, you can set the row start.

Specify the Row Start Position

In this exercise you are tasked with moving an element to a specific location.

Positioning with grid-column-start and grid-row-start

Practice Positioning Elements

In addition to specifying the start lines, we can specify where an element should end.

Specify the End Line

Test your understanding by reproducing a given layout.

Positioning Across Multiple Rows & Columns with Span

Practice Moving and Spanning Grid Items

So far we've been specifying columns and rows manually. CSS Grid offers a shorthand syntax that will save you some keystrokes.

Grid Column and Row Shorthand

Use the grid row and column shorthand to position multiple boxes in a layout.

Positioning with Shorthand

Practice Shorthand Positioning

The `grid-area` property gives us another way to position an element using grid lines.

Positioning an Element with grid-area

Using the span Keyword to Position Elements

Test what you've learned so far by duplicating a layout using shorthand syntax and the span keyword.

Specific Placement with Shorthand Properties and Span

Practice Duplicating a Layout with Shorthand Properties and Span

Until now we've been counting grid numbers. CSS Grid allows you to add names to lines, then position items accordingly.

Customize Grid Line Names

Positioning Elements by Lines

So far we've primarily used numbers when defining layouts. Before we look at an alternative, let's build the layout that will be reproduced.

Building an Example Layout with Numbered Columns and Rows

Using what you've learned so far, practice using CSS Grid to create a web page layout.

Web Page Layout Solution

Practice Creating a Web Page Layout

CSS Grid's `grid-template-areas` property allows you to assign names to the areas between track lines.

Naming Areas of the Grid

Once you've named your grid areas, you can assign elements to use that space.

Assigning Elements to Named Grid Areas

Recreate a layout using named areas instead of line numbers.

Recreate a Layout Using Named Grid Areas

Practice Using Grid Template Areas

From just a visual of a layout, you can reason about how the grid areas should be defined.

Creating a Complex Layout with Grid Areas

CSS Grid allows you to leave an empty space in your grid layout, while specifying how other elements flow.

Leaving Empty Spaces in Grid Template Areas

Grid Areas

So far we've explicitly specified the behavior of our grid layouts. However, there is also implicit grid behavior that affects how content is placed.

Understanding the Implicit Grid in CSS Grid

Test your understanding of the implicit grid by recreating a layout that dynamically supports any number of elements.

Dynamically Setting Row Heights in a Layout

Create a Dynamic Grid with Equally Sized Boxes

The `grid-auto-flow` property can be used to change the default direction of element placement in CSS Grid.

Changing the Default Placement Algorithm

The `dense` modifier keyword tells CSS Grid to pack elements into the grid.

Row Dense and Column Dense Auto Flow

Test your understanding of how to modify the behavior of grid elements.

Change Grid Content Flow

Grid Direction Exercise

In addition to rows, column behavior in the implicit grid can be modified.

Grid Auto Columns and the Implicit Grid

The Implicit Grid

CSS Grid's `minmax` function allows you to define minimum and maximum sizes for grid items.

Specify Ranges with the minmax Function

Combining `repeat` function works well with `minmax` to define flexible layouts without the constraints of hard-coded values.

Combining minmax with repeat to Define Layouts

Test your understanding by recreating a given layout.

Specify a Minimum Column Size with minmax

Practice Recreating a Minimum Size Layout

Media queries can be used to define grid behavior when the viewport reaches a given size.

Define a Responsive Grid with Media Queries

CSS Grid can responsively resize and reorder elements as the screen size changes.

Responsively Changing Grid Template Areas

Test your understanding of media queries and `grid-template-areas` to make a layout reponsive

Updating a Layout to be Responsive

Practice Implementing Responsive Grid Template Areas

The `auto-fit` feature in CSS Grid allows you to create a layout that adapts to different screen sizes without the need for media queries.

Automatic Responsiveness with Auto Fit

Test your understanding by recreating a layout that adapts to different screen sizes.

Defining Grid Template Columns with Auto Fit

Practice Defining a Responsive Layout

The `auto-fit` and `auto-fill` features in CSS Grid have similar names and functionality, but there are some nuances to their behavior.

Comparing auto-fill and auto-fit

Creating Responsive Grids

An overview of one of the most common page layouts and how it behaves at different viewport sizes.

Overview of a Common Layout

We'll start by implementing the layout as a mobile-style single column layout.

Defining a Single-Column Layout

Moving on, we'll add a media query to shift the layout to use two columns.

Adding a Two-Column Layout

With the smaller viewport layouts taken care of, we'll implement a layout for large screen sizes.

Adding a Large Screen Layout

In this example we'll look at implementing a responsive layout that supports cards of different sizes without writing media queries.

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Converting a Single-Column Layout

Starting HTML & CSS

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