Use CSS (and maybe JavaScript) to make an element be square (or maintain a specific aspect ratio)

Question

I have a div that I want to have the following characteristics:

• Width = 50% of its parent element
• Height equal to whatever it needs to be in order to

Answer 1

Here's a pure CSS version with no img tag:

SCSS (include Compass to render the background-size):

.apple_container {
  width: 50%;
}
.apple_icon {
  padding-bottom: 100%;
  background-image: url(/images/apple.png);
  background-repeat: no-repeat;
  @include background-size(contain);
  background-position: center center;
}

CSS generated from the above:

.apple_container {
  width: 50%;
}
.apple_icon {
  padding-bottom: 100%;
  background-image: url(/images/apple.png);
  background-repeat: no-repeat;
  -webkit-background-size: contain;
  -moz-background-size: contain;
  -o-background-size: contain;
  background-size: contain;
  background-position: center center;
}

Results in a square element with a background image centered and fitted within it. This is good for responsive elements that you want to resize dependent on the user's device.