Gain insights into designing mobile-responsive web layouts using Flexbox. Delve into Box Model basics, Flexbox containers, and item alignment, and apply your knowledge to create stunning, mobile-first websites.

CBCA - CSS with Flexbox (Intermediate)-01.jpg

In this course, you will get hands-on experience in designing mobile-responsive web layouts using Flexbox. You will start with the basics like the Box Model and the process of layouting.

You will then move on to advanced concepts such as Flexbox containers, and aligning individual Flexbox items. Near the end of the course, you will put everything you just learned into practice. You will work on a project that focuses on developing a mobile-first website where you’ll experiment with page layout, headers, footers, and a lot more.

By the end of this course, you will be able to use Flexbox in your own projects to create beautiful layouts.

Designing Web Layouts with CSS and Flexbox

# Whitespaces take space

Let's recall the previous exercise, but this time, let's also add a proper height to the elements, and let's create six divs instead of three:

```html
<div class="container"><div class="col">First</div><div class="col">Second</div><div class="col">Third</div><div class="col">Fourth</div><div class="col">Fifth</div><div class="col">Sixth</div></div>
``` 

```css
.container { 
  margin: 50px; 
  padding: 0; 
}

.col { 
  display: inline-block; 
  border: 2px solid black; 
  width: 33.33%; 
  box-sizing: border-box; 
  margin: 0 auto; 
  height: 100px; 
  background-color: lightblue;
}
```

The six elements are rendered as follows: 

![](/api/collection/6003536328392704/5350022716063744/page/5747903318982656/image/6467543775051776)

Let's remove the comments from the HTML:

```html
<div class="container">
    <div class="col">First</div>
    <div class="col">Second</div>
    <div class="col">Third</div>
    <div class="col">Fourth</div>
    <div class="col">Fifth</div>
    <div class="col">Sixth</div>
</div>
``` 

![](/api/collection/6003536328392704/5350022716063744/page/5747903318982656/image/4823160822693888)

No comment... pun intended.

Our three-column layout fell apart because whitespaces take space. 

To combat this, we have to set the font size of the container to zero. To make sure the elements retain their font size, we have to explicitly specify the font size in all elements inside the container.

```css
.container { 
  margin: 50px; 
  padding: 0; 
  font-size: 0;
}

.col { 
  display: inline-block; 
  border: 2px solid black; 
  width: 33.33%; 
  box-sizing: border-box; 
  margin: 0 auto; 
  height: 100px; 
  background-color: lightblue;
  font-size: 16px;
}
```

Let's add some more text inside the first element:

```html
<div class="container">
    <div class="col">
        First 
        <p>Lorem ipsum.</p>
    </div>
    <div class="col">Second</div>
    <div class="col">Third</div>
    <div class="col">Fourth</div>
    <div class="col">Fifth</div>
    <div class="col">Sixth</div>
</div>
``` 

The page falls apart.

![](/api/collection/6003536328392704/5350022716063744/page/5747903318982656/image/5714980939235328)

To fix this, we have to add the `vertical-align: middle;` rule to each element.

```css
.container { 
  margin: 50px; 
  padding: 0; 
  font-size: 0;
}

.col { 
  display: inline-block; 
  border: 2px solid black; 
  width: 33.33%; 
  box-sizing: border-box; 
  margin: 0 auto; 
  height: 100px; 
  background-color: lightblue;
  font-size: 16px;
  vertical-align: middle;
}
```

Finally, after so many fixes, we can use our three-column layout without major restrictions as long as the content inside an element doesn't exceed the height of the `.col` element. This is because the content will be hidden by the `.col` element(s) directly below the element with the long content.

Play around with the content a bit more to see how inline-block elements are created.

# Whitespaces take space

Let's recall the previous exercise, but this time, let's also add a proper height to the elements, and let's create six divs instead of three:

```html
<div><div>First</div><div>Second</div><div>Third</div><div>Fourth</div><div>Fifth</div><div>Sixth</div></div>
``` 

```css
.container { 
  margin: 50px; 
  padding: 0; 
}

.col { 
  display: inline-block; 
  border: 2px solid black; 
  width: 33.33%; 
  box-sizing: border-box; 
  margin: 0 auto; 
  height: 100px; 
  background-color: lightblue;
}
```

The six elements are rendered as follows: 

![](/api/collection/6003536328392704/5350022716063744/page/5747903318982656/image/6467543775051776)

Let's remove the comments from the HTML:

```html
<div>
    <div>First</div>
    <div>Second</div>
    <div>Third</div>
    <div>Fourth</div>
    <div>Fifth</div>
    <div>Sixth</div>
</div>
``` 

![](/api/collection/6003536328392704/5350022716063744/page/5747903318982656/image/4823160822693888)

No comment... pun intended.

Our three-column layout fell apart because whitespaces take space. 

To combat this, we have to set the font size of the container to zero. To make sure the elements retain their font size, we have to explicitly specify the font size in all elements inside the container.

```css
.container { 
  margin: 50px; 
  padding: 0; 
  font-size: 0;
}

.col { 
  display: inline-block; 
  border: 2px solid black; 
  width: 33.33%; 
  box-sizing: border-box; 
  margin: 0 auto; 
  height: 100px; 
  background-color: lightblue;
  font-size: 16px;
}
```

Let's add some more text inside the first element:

```html
<div>
    <div>
        First 
        <p>Lorem ipsum.</p>
    </div>
    <div>Second</div>
    <div>Third</div>
    <div>Fourth</div>
    <div>Fifth</div>
    <div>Sixth</div>
</div>
``` 

The page falls apart.

![](/api/collection/6003536328392704/5350022716063744/page/5747903318982656/image/5714980939235328)

To fix this, we have to add the `vertical-align: middle;` rule to each element.

```css
.container { 
  margin: 50px; 
  padding: 0; 
  font-size: 0;
}

.col { 
  display: inline-block; 
  border: 2px solid black; 
  width: 33.33%; 
  box-sizing: border-box; 
  margin: 0 auto; 
  height: 100px; 
  background-color: lightblue;
  font-size: 16px;
  vertical-align: middle;
}
```

Finally, after so many fixes, we can use our three-column layout without major restrictions as long as the content inside an element doesn't exceed the height of the `.col` element. This is because the content will be hidden by the `.col` element(s) directly below the element with the long content.

Play around with the content a bit more to see how inline-block elements are created.

We will revisit the three column layout with inline-block display mode to understand why traditional layouting is not intuitive.

Getting Started

Using Flexbox Containers

Aligning Individual Flexbox Items

Designing a Mobile-first Website Using Flexbox

Flexbox Conclusion and Next Steps

Challenges with Traditional Layouting

Whitespaces take space