CSS basic user interface

The CSS basic user interface module allows you to define the rendering and functionality of features related to the user interface, including outline properties, visual feedback for pointing devices and keyboards, and modifying the default appearance of UI widgets.

Basic user interface properties can be used to improve user experience and accessibility by providing visual cues to elements that are being interacted with, including styling mouse cursors and keyboard directional focus navigation, and styling caret cursors when an editable element has focus. The module includes features for providing outlines to focused (or unfocused) elements without impacting an element's box model dimensions and styling. This UI module also enables the styling of user interface controls.

Basic user interface in action

To view how basic user interface properties can alter the appearance of UI features, interact with the elements in this sample. Note that some features in this sample improve usability while others harm user experience.

<div><span contenteditable>Edit this text </span></div>
<fieldset>
  <legend>Play with these fake form controls</legend>
  <input type="checkbox" id="check" />
  <input type="radio" name="a" />
  <input type="radio" name="a" />
  <input type="range" />
  <progress></progress>
</fieldset>
<fieldset>
  <legend>Be careful not to ruin usability: try resizing these.</legend>
  <textarea>
  cursor: wait;
  </textarea>
  <textarea>
  resize: none;
  </textarea>
  <textarea>
  pointer-events: none;
  </textarea>
</fieldset>

body {
  font-family: sans-serif;
  font-size: 1.25rem;
}
[contenteditable] {
  cursor: copy;
  caret-color: magenta;
  border: 1px solid #cccccc;
}
:focus {
  outline: dashed magenta 3px;
  outline-offset: 10px;
}
* {
  accent-color: magenta;
}
div,
fieldset {
  margin: 20px;
}
textarea:nth-of-type(1) {
  cursor: wait;
}
textarea:nth-of-type(2) {
  resize: none;
}
textarea:nth-of-type(3) {
  pointer-events: none;
}

The CSS outline and outline-offset properties were used to provide feedback to users on which element currently has focus. An accent-color provides a theme color to all the form controls. The caret that appears when the text is edited has the same color thanks to the caret-color property. These can all be considered UI improvements.

Some features harm usability. The cursor property was used to change cursors from the browser default, which is confusing. The resize property prevents the second <textarea> from being resizable while the pointer-events property prevents the third <textarea> from receiving click events. It is still focusable using the keyboard.

Click "Play" in the example above to see or edit the code for the animation in the MDN Playground.

Reference

Properties

accent-color
appearance
caret-animation
caret-color
caret-shape
cursor
interest-delay, shorthand for:
- interest-delay-start
- interest-delay-end
outline, shorthand for:
outline-offset
pointer-events
resize
user-select

The CSS basic user interface module also defines the caret, nav-down, nav-left, nav-right, and nav-up properties. Currently, no browsers support these features.