Animate an element's width from 0 to 100%, with it and it's wrapper being only as wide as they need to be, without a pre-set width, in CSS3 or jQuery

Question

http://jsfiddle.net/nicktheandroid/tVHYg/

When hovering .wrapper, it\'s child element .contents should animate from 0px to it\

Answer 1

a late answer, but I think this one works as required in the question :)

this one uses z-index and position absolute, and avoid the issue that the container element width doesn't grow in transition.

You can tweak the text's margin and padding to suit your needs, and "+" can be changed to font awesome icons if needed.

body {
  font-size: 16px;
}

.container {
  height: 2.5rem;
  position: relative;
  width: auto;
  display: inline-flex;
  align-items: center;
}

.add {
  font-size: 1.5rem;
  color: #fff;
  cursor: pointer;
  font-size: 1.5rem;
  background: #2794A5;
  border-radius: 20px;
  height: 100%;
  width: 2.5rem;
  display: flex;
  justify-content: center;
  align-items: center;
  position: absolute;
  z-index: 2;
}

.text {
  white-space: nowrap;
  position: relative;
  z-index: 1;
  height: 100%;
  width: 0;
  color: #fff;
  overflow: hidden;
  transition: 0.3s all ease;
  background: #2794A5;
  height: 100%;
  display: flex;
  align-items: center;
  border-top-right-radius: 20px;
  border-bottom-right-radius: 20px;
  margin-left: 20px;
  padding-left: 20px;
  cursor: pointer;
}

.container:hover .text {
  width: 100%;
  padding-right: 20px;
}

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