CSS layout has grown and evolved into a robust set of tools to accomplish some fantastic modern layouts.
The problem is that we are still teaching CSS as something that is" hacked" together by using" tricks" to get our desired web layouts.
Learning CSS like this typically leads us down one of two paths: We either build fragile page layouts using 
the "see what sticks" method of CSS, or we give up and declare that CSS is too tricky and bring in an X column grid system like Twitter Bootstrap.

Creating page layouts in CSS doesn't have to be complicated. Like how you make much of your everyday speech using just a small 
subset of vocabulary composed together, you can achieve sophisticated layouts by composing simple low-level layout primitives in unique ways.

In this course, you will learn foundational layout primitives that you can use to build many of your more complex layouts. You will also learn 
how to apply the principle of "Encapsulated CSS" to both extend these primitives as well as to create custom layout primitives. To do this, we 
will recreate many of the layouts found in the wild using the principles mentioned above.

This course does not require extensive knowledge of CSS. It does assume that you have a basic understanding of the CSS box model, CSS specificity, 
CSS selectors, and CSS sizing units. Though you can apply the principles in this course to any modern web framework, including no framework 
development, this course will be using React and assume you have a basic understanding of React, JSX, and React hooks.

Composing Layout in React is for both novice and experienced developers who want to take their layout skills to the next level. This course will 
teach you the practical skills you need to build modern layouts for the web without depending on heavy CSS frameworks. Unlike courses and blog 
posts that teach each layout property in isolation, our product teaches practical layout patterns that you can use every day when solving your 
layout challenges.

In this course we show you how to build complex layouts in React by composing just a few foundational layout primitives.
Along the way you will learn modern CSS Layout tools like Normal Flow, Flexbox, and Grid.

Composing Layouts in React

---
title: How to Add Inline Styling to React Components
slug: inline-component
description: Clustering is one way to do responsive inline layouts, but sometimes we want to switch the direction that the items are flowing when we cross a certain threshold.  In this lesson, we will learn how to build the Inline primitive that does just that.
isPublicLesson: false
privateVideoUrl: https://fullstack.wistia.com/medias/7c5j9bxorn
useMdx: true
code: https://gitlab.com/fullstackio/books/newline-course-apps/travis-waith-mair-composing-layout-in-react-app/-/tree/main/module_03/lesson_06
---

The InlineCluster primitive solved a very common inline layout problem. However, there is another common problem which is similar but needs its own custom solution. In this lesson, we will learn how to make a variant of the InlineCluster, called Inline, which will let us stretch one or more items. It will also allow us to switch to a stack layout when the width decreases below a threshold.

## The problem: the MenuBar v2

In this lesson, we are going to build a second version of our MenuBar widget:

![Menu Bar mockup wide](https://d2uusema5elisf.cloudfront.net/courses/composing-layouts-in-react/module_03/lesson_03.06/public/assets/inline-red-line.png)

In this version of the MenuBar, we need to have everything stay inline and not cluster. In addition, we need the center section to stretch and fill the extra available space, but cluster in the center when there is no extra space available.

It will also need to switch from a horizontal, inline layout to a vertical, stack layout when the inline size is less than a `40rems`, like this:

![Menu Bar mockup narrow](https://d2uusema5elisf.cloudfront.net/courses/composing-layouts-in-react/module_03/lesson_03.06/public/assets/inline-red-narrow.png)

## The solution

You can [follow along by forking the codesandbox.io starter project.](https://codesandbox.io/s/heading-example-starter-0nekx)

In our MenuBar, we need items in the middle section (the menu items) to cluster in the center. We already have a primitive that solves that problem: the InlineCluster primitive. Let's look at our initial markup, which is already using the InlineCluster primitive:

```jsx { actualFilename=./protected/inline-0.js endChar=621 endLine=26 startChar=0 startLine=1 url=https&#x3A;//gitlab.com/fullstackio/books/composing-layouts-in-react/module_03/lesson_03.06/protected/inline-0.js }
import React from "react";
import { InlineCluster } from "./InlineCluster";
import { Logo, MenuContainer, Button } from "./MenuParts";

export default function MenuBar() {
  return (
    <MenuContainer>
      <div>
        <div>
          <Logo />
        </div>
        <InlineCluster gutter="md" justify="center" align="center">
          <span>Product</span>
          <span>Features</span>
          <span>Marketplace</span>
          <span>Company</span>
        </InlineCluster>
        <div>
          <span>Sign in</span>
          <Button>Sign up</Button>
        </div>
      </div>
    </MenuContainer>
  );
}
```

And this is how it looks:

![Menu Bar step 0](https://d2uusema5elisf.cloudfront.net/courses/composing-layouts-in-react/module_03/lesson_03.06/public/assets/inline-0.png)

In the above code, we have separated our menu into three parts, the logo, the menu items, and our sign-in/sign-up sections. Here is the same image, with the three sections colored to make it easier to see:

![Menu Bar step 0 with color bars](https://d2uusema5elisf.cloudfront.net/courses/composing-layouts-in-react/module_03/lesson_03.06/public/assets/inline-0-with-colors.png)

The next thing we need to do is move these sections to be inline, but this time we don't want them to cluster like the `InlineCluster`. So let's start making our Inline primitive. The `Inline` primitive needs to do all the things that the `InlineCluster` can do, like setting the `gutter`, `justify`, and `align` props. The only thing we don't want it to do is cluster. Luckily, we don't have to recreate all those same properties again on our `Inline` primitive. We are going to take advantage of `styled-components` ability to extend the styles of other components:

```jsx { actualFilename=./protected/inline-1.js endLine=12 startLine=6 url=https&#x3A;//gitlab.com/fullstackio/books/composing-layouts-in-react/module_03/lesson_03.06/protected/inline-1.js#L6 }
const Inline = styled(InlineCluster)`
  flex-wrap: nowrap;

  > * {
    flex: 1;
  }
`;
```

In the above code, we pass the `InlineCluster` as an argument to `styled`. Doing that will mean that we have all the style logic of the InlineCluster, but now we can build on top of it. Unlike the menu items in the middle, we don't want our menu bar components to cluster. To prevent clustering we need to override the `flex-wrap` property set in the `InlineCluster` by setting it `flex-wrap` in the `Inline` primitive to `nowrap`.

One of the requirements we need to fulfill is to have the menu items in the center to grow to take up all available space. One of the properties you can set on a `flex-item` is the `flex` property. The `flex` property can be passed a number and it will stretch to fill as much space as possible. Only those `flex-items` that have the `flex` property set will grow and it will grow in relation to other `flex-items` value.

Based on the rules of Encapsulated CSS, we know we need to set values like `flex` that impact the layout of an element in the parent component. In the above code, we are using the direct child combinator to set the `flex` property to `1` on all the three direct children, the logo, the menu items, and the sign-in/sign-up section. By setting all the direct children to have a `flex` value of 1, they will all grow equally.

Now we can wrap our start using the `Inline` primitive, like this:

```jsx { actualFilename=./protected/inline-1.js endLine=31 startLine=17 url=https&#x3A;//gitlab.com/fullstackio/books/composing-layouts-in-react/module_03/lesson_03.06/protected/inline-1.js#L17 }
      <Inline>
        <div>
          <Logo />
        </div>
        <InlineCluster gutter="md" justify="center" align="center">
          <span>Product</span>
          <span>Features</span>
          <span>Marketplace</span>
          <span>Company</span>
        </InlineCluster>
        <div>
          <span>Sign in</span>
          <Button>Sign up</Button>
        </div>
      </Inline>
```

And now our menu looks like this:

![Menu Bar step 1](https://d2uusema5elisf.cloudfront.net/courses/composing-layouts-in-react/module_03/lesson_03.06/public/assets/inline-1.png)

And here is that same image with colors to make the sections easier to see:

![Menu Bar step 1 with colored sections](https://d2uusema5elisf.cloudfront.net/courses/composing-layouts-in-react/module_03/lesson_03.06/public/assets/inline-1-with-color.png)

Sometimes, we want all items to stretch uniformly this way, but for our menu bar we want only the second item to stretch. What we need is a way to set which item or items will stretch and grow. Let's add a prop called `stretch` that accepts either a number that represents the index of the child that we want to stretch, or the strings: `all`, `start`, or `end`. Let's do a little refactoring:

```jsx { actualFilename=./protected/inline-2.js endLine=21 startLine=6 url=https&#x3A;//gitlab.com/fullstackio/books/composing-layouts-in-react/module_03/lesson_03.06/protected/inline-2.js#L6 }
const stretchMap = {
  all: `> *  { flex: 1 }`,
  start: `> :first-child { flex: 1 }`,
  end: `> :last-child { flex: 1 }`,
};

const Inline = styled(InlineCluster)`
  flex-wrap: nowrap;

  ${({ stretch }) => {
    if (typeof stretch === "number")
      return `> :nth-child(${stretch + 1}) { flex: 1 }`;

    return stretchMap[stretch] ?? "";
  }}
`;
```

In the above code, we check to see if the `stretch` prop is a number. If it is, we will use the `:nth-child` pseudo selector. The `:nth-child` pseudo selector allows you to select an element that is the "nth child". We just need to pass into the selector which child it is that we want to have stretched. For example, if we wanted to select the third child, we would write our selector `> :nth-child(3){}`. In JavaScript, index numbers start at `0`, but in CSS indexes start at `1`. So we need to add one to our number to convert from a 0-based index to a 1-based index, which is why our code will return `> :nth-child(${stretch + 1}) { flex: 1 }`.

Clustering is one way to do responsive inline layouts, but sometimes we want to switch the direction that the items are flowing when we cross a certain threshold.  In this lesson, we will learn how to build the Inline primitive that does just that.