如何在伪元素中旋转文本？

Question

I'm trying to rotate the double angle bracket set as the content in an :after pseudo-element using the css transform value rotate(90deg) for a tab across the top of the screen. Here's the relevant code:

 .header { -moz-transition: top .5s ease; -webkit-transition: top .5s ease; -o-transition: top .5s ease; transition: top .5s ease; position: absolute; left: 0; right: 0; top: -60px; height: 80px; background-color: #2d2; } .header.in-top { top: 0; } .header-tab { position: absolute; bottom: 0; width: 100%; height: 20px; text-align: center; color: #000; -moz-transition: color .5s ease; -webkit-transition: color .5s ease; -o-transition: color .5s ease; transition: color .5s ease; } .header-tab:hover { color: #e22; } .header-arrow:after { font-size: 20px; line-height: 1; -moz-transform: rotate(90deg); -webkit-transform: rotate(90deg); -ms-transform: rotate(90deg); -o-transform: rotate(90deg); transform: rotate(90deg); } .header .header-arrow:after { content: "\\00bb"; } .header.in-top .header-arrow:after { content: "\\00ab"; } 

 <div class="header"> <div class="header-tab" data-toggle="in-top"> <span class="header-arrow"></span> </div> </div> 

The data-toggle attribute is used in JavaScript to toggle the in-top class in order to switch the direction of the double angle bracket as well as to expose the content of the header by bringing it down. The transform properties I have specified seem to do nothing though. Any solutions?

Answer 1

Use display: inline-block on the pseudo-element. Alternatively, inline-table or block should also work.

See jsFiddle .

Your pseudo-element is displayed inline by default, which makes it a nontransformable element. From the CSS Transforms Working Draft specification :

transformable element

A transformable element is an element in one of these categories: an element whose layout is governed by the CSS box model which is either a block-level or atomic inline-level element, or whose 'display' property computes to 'table-row', 'table-row-group', 'table-header-group', 'table-footer-group', 'table-cell', or 'table-caption'

Answer 2

You need to set the pseudo-element as a block or inline-block element:

.header-arrow:after {
  display: block;
}

The specification says rotation should work on inline elements, but in WebKit based browsers it doesn't works: https://www.webkit.org/blog/130/css-transforms/

Answer 3

Rotate property will apply on pseudo-element(after/before) only when you will use display:inline-block; or display:inline-block; property in your class or selector.

.className:before{
   -webkit-transform: rotateZ(180deg); /* Safari */
  transform: rotateZ(180deg); /* Standard syntax */
    display: inline-block;
}