Basic CSS: Borders in CSS

Lesson 11: Borders in CSS


Borders in CSS

diagram of box model with borders highlighted

If you want to add emphasis to an element, one option is to add borders. You can adjust the border style, width, and color to get a variety of different looks.

The border declaration

The border box directly surrounds the padding box, and is usually used to represent the outer boundary of your content. A simple border declaration might look like this:

border: solid 3px black;

That declaration means that the padding box should be surrounded by a solid black border that is 3px thick. For example, consider a <p> element with some text, some color declarations, and a padding declaration. On a webpage, it might look like this:

Paragraph with no border

If you were to add a simple border declaration like the one above, you'd see this:

Paragraph with a border

Like the padding declaration, the border declaration is actually a shorthand to summarize a number of separate declarations that could also be used individually. It defines three basic elements of an element's border:

  • Style: The type of border to display. Most of the borders you'll see and use will be solid, but CSS can create other styles such as dashed and dotted borders. The border-style declaration can define it individually.
  • Width: The thickness of the border. You'll usually see the value given in pixels, and the border-width declaration can define it individually.
  • Color: The color of the border. You can use named colors or hex codes, just as you do for the color or background-color declarations. The border-color declaration can define it individually.

Rounded borders

So far, all of our elements have been rectangular. But you can also create rounded rectangles and other shapes using the border-radius property.

For example, you could round the corners slightly with border-radius: 10px;:

paragraph with a 10 pixel border radius

Or you could use a larger radius such as border-radius: 100px; to create a pill shape:

paragraph with a large border radius, creating a pill shape

When working with square elements, you can use border-radius: 50%; to create a circle:

square div with a 50 percent border radius, creating a circle

Despite the name, border-radius can also be used when there is no border:

paragraph with a 10 pixel border radius and no border, with teal background

Try this!

Try adding each of these declarations, one by one, to the input below:

background-color: #15AAD7;
color: white;
padding: 10px;
border: solid 3px #0F7391;

The selector for the ruleset is already defined for you, and targets the paragraph to its right. Once you've tried those declarations, try changing some of the values yourself. For example, try changing the "solid" value in your border declaration to "dashed" or "dotted," or try changing the width value.

Do it yourself!

Open the styles.css file in your GCF Programming Tutorials project in your text editor, and let's add some borders. For the best understanding, be sure to actually type this code in, rather than copying and pasting it.

  1. Finally, let's make that button look a little bit better. Because it's a button, it has a default border, but let's give it a nicer one. Add this to the button ruleset:
    border: solid 2px #1B7530;
    border-radius: 50px;
  2. Optional: Try changing the border style, width, and color to see how it affects the button. You can also change the color and background-color for the button to try different color combinations.

If you load your index.html file in your browser or refresh the page, you should now see a webpage that looks much less cramped. It should look something like this.

Congratulations, you've explored the box model on your webpage!