The Box Model

All HTML elements can be considered as boxes. In CSS, the term “box model” is used when talking about design and layout.

The CSS box model is essentially a box that wraps around every HTML element. It consists of margins, borders, padding, and the actual content.

• Content: The content of the box, where text and images appear
• Padding: Clears an area around the content. The padding is transparent
• Border: A border that goes around the padding and content
• Margin: Clears an area outside the border. The margin is transparent

Box elements styles

Well…every element is a box, but let’s focus on <div>, <ul>, <ol> and also the previous text elements.

• width: 500px; (px, em, rem, %)
• height: 250px; (px, em, rem)
• border: 5px solid #CC0000; (px, em, rem; solid, dotted, dashed; hex, name, rgb, rgba)
• padding: 10px 20px 10px 20px; (px, em, rem)
• margin: 10px auto 30px auto; (px, em, rem)

Here is an example

div {
    background-color: #eeeeaa;
    padding: 16px 24px;
    margin: 32px auto;
    border: 3px solid #00cc00;
    width: 50%;
}
p {
    text-align: center;
    font-size: 24px;
    font-weight: bold;
    font-style: italic;
    color: #990000;
}

The Result:

box-sizing

• width + padding + border = actual visible/rendered width of an element’s box
• The default is a little counter-intuitive, hence we have box-sizing

Learn more

• box-sizing