Underline from left to right on hover in and out [duplicate]

Question

With the following code I get an hover underline effect from left to right.

.underline {
  display: inline;
  position: relative;
  overflow: hidden;
}
.underline:after {
  content: "";
  position: absolute;
  z-index: -1;
  left: 0;
  right: 100%;
  bottom: -5px;
  background: #000;
  height: 4px;
  transition-property: left right;
  transition-duration: 0.3s;
  transition-timing-function: ease-out;
}
.underline:hover:after,
.underline:focus:after,
.underline:active:after {
  right: 0;
}

<p>hello, link is <a href="#" class="underline">underline</a>
</p>

When you're not in hover, the :after element returns to the left, the initial state. Is there any way that the :after goes to the right and not to the left when you leave the hover?

Answer 1

You can try animating the width instead of the right/left properties.

.underline {
  display: inline;
  position: relative;
  overflow: hidden;
}
.underline:after {
  content: "";
  position: absolute;
  z-index: -1;
  right: 0;
  width: 0;
  bottom: -5px;
  background: #000;
  height: 4px;
  transition-property: width;
  transition-duration: 0.3s;
  transition-timing-function: ease-out;
}
.underline:hover:after,
.underline:focus:after,
.underline:active:after {
  left: 0;
  right: auto;
  width: 100%;
}

<p>hello, link is <a href="#" class="underline">underline</a></p>

See this fiddle for a working example: https://jsfiddle.net/1gyksyoa/

Answer 2

Based on this answer : Expand bottom border on hover you can change the transform-origin property on hover to achieve the "hover out" effect you are looking for. Here is an example :

.expand{
  position:relative;
  text-decoration:none;
  display:inline-block;
}
.expand:after {
  display:block;
  content: '';
  border-bottom: solid 3px #000;  
  transform: scaleX(0);  
  transition: transform 250ms ease-in-out;
  transform-origin:100% 50%
}
.expand:hover:after { 
  transform: scaleX(1);
  transform-origin:0 50%;
}

Here is some dummy text <a href="#" class="expand">expand</a>