CSS3 User Interface

CSS3 has new user interface features such as resizing elements, outlines, and box sizing.

In this chapter you will learn about the following user interface properties:

• resize
• outline-offset

CSS3 Resizing

The resize property specifies whether or not an element should be resizable by the user.

The following example lets the user resize only the width of a <div> element:

Example

div {
    resize: horizontal;
    overflow: auto;
}

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The following example lets the user resize only the height of a <div> element:

Example

div {
    resize: vertical;
    overflow: auto;
}

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The following example lets the user resize both the height and the width of a <div> element:

Example

div {
    resize: both;
    overflow: auto;
}

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CSS3 Outline Offset

The outline-offset property adds space between an outline and the edge or border of an element.

Outlines differ from borders in three ways:

• An outline is a line drawn around elements, outside the border edge
• An outline does not take up space
• An outline may be non-rectangular

The following example uses the outline-offset property to add a 15px space between the border and the outline:

Example

div {
    border: 1px solid black;
    outline: 1px solid red;
    outline-offset: 15px;
}

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CSS3 User Interface Properties

The following table lists all the user interface properties:

Property	Description
box-sizing	Allows you to include the padding and border in an element's total width and height
nav-down	Specifies where to navigate when using the arrow-down navigation key
nav-index	Specifies the tabbing order for an element
nav-left	Specifies where to navigate when using the arrow-left navigation key
nav-right	Specifies where to navigate when using the arrow-right navigation key
nav-up	Specifies where to navigate when using the arrow-up navigation key
outline-offset	Adds space between an outline and the edge or border of an element
resize	Specifies whether or not an element is resizable by the user