::after (:after) - CSS: Cascading Style Sheets 编辑

In CSS, ::after creates a pseudo-element that is the last child of the selected element. It is often used to add cosmetic content to an element with the content property. It is inline by default.

/* Add an arrow after links */
a::after {
  content: "→";
}

Note: The pseudo-elements generated by ::before and ::after are contained by the element's formatting box, and thus don't apply to replaced elements such as <img>, or to <br> elements.

Syntax

/* CSS3 syntax */
::after

/* CSS2 syntax */
:after

Note: CSS3 introduced the ::after notation (with two colons) to distinguish pseudo-classes from pseudo-elements. Browsers also accept :after, introduced in CSS2.

Examples

Simple usage

Let's create two classes: one for boring paragraphs and one for exciting ones. We can use these classes to add pseudo-elements to the end of paragraphs.

HTML

<p class="boring-text">Here is some plain old boring text.</p>
<p>Here is some normal text that is neither boring nor exciting.</p>
<p class="exciting-text">Contributing to MDN is easy and fun.</p>

CSS

.exciting-text::after {
  content: " <- EXCITING!";
  color: green;
}

.boring-text::after {
  content: " <- BORING";
  color: red;
}

Result

Decorative example

We can style text or images in the content property almost any way we want.

HTML

<span class="ribbon">Look at the orange box after this text. </span>

CSS

.ribbon {
  background-color: #5BC8F7;
}

.ribbon::after {
  content: "This is a fancy orange box.";
  background-color: #FFBA10;
  border-color: black;
  border-style: dotted;
}

Result

Tooltips

This example uses ::after, in conjunction with the attr() CSS expression and a data-descr custom data attribute, to create tooltips. No JavaScript is required!

We can also support keyboard users with this technique, by adding a tabindex of 0 to make each span keyboard focusable, and using a CSS :focus selector. This shows how flexible ::before and ::after can be, though for the most accessible experience a semantic disclosure widget created in some other way (such as with details and summary elements) is likely to be more appropriate.

HTML

<p>Here we have some
  <span tabindex="0" data-descr="collection of words and punctuation">text</span> with a few
  <span tabindex="0" data-descr="small popups that appear when hovering">tooltips</span>.
</p>

CSS

span[data-descr] {
  position: relative;
  text-decoration: underline;
  color: #00F;
  cursor: help;
}

span[data-descr]:hover::after,
span[data-descr]:focus::after {
  content: attr(data-descr);
  position: absolute;
  left: 0;
  top: 24px;
  min-width: 200px;
  border: 1px #aaaaaa solid;
  border-radius: 10px;
  background-color: #ffffcc;
  padding: 12px;
  color: #000000;
  font-size: 14px;
  z-index: 1;
}

Result

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• ::before
• content