website/content/blog/2015-09-14-animatable-box-model.md

---
id: 155
title: 'Animatable: Box Model'
date: 2015-09-14T12:07:52+00:00
author: Brandon Rozek
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    - /2015/09/animatable-box-model/
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tags: ["Web", "CSS"]
---
This post is part 2 of an animation series I am doing; you can read part 1 [here](https://brandonrozek.com/2015/05/animatable-border/). In this post, we’ll look at the different parts of the box model (margin, padding, height, and width) and see how they can be animated.

<!--more-->

The W3C has a great starting reference for the [CSS Box Model](http://www.w3.org/TR/CSS2/box.html). It can be wordy at times, but has everything you need to know. I had never heard of _margin collapsing_ until I read that. Luckily there is a great [post](https://css-tricks.com/what-you-should-know-about-collapsing-margins/) on CSS-Tricks written by Geoff Graham explaining what it is. To see it all in action, take a look at this Codepen [demo](http://codepen.io/brandonrozek/full/RWPYgV/){.broken_link}&#8211;  I reference this multiple times in this post. Now, on to the box model.

### Margin

  * Accepts 1 to 4 numerical values (negative numbers are allowed)
  * If you use 4 values, the first value is the top margin and the rest follow in a clockwise fashion
  * Initial value: 0

Margins can be described as the space around an element. In the Codepen demo (#1), it shows 2 boxes. The first box has a margin-right that is increasing, making it seem as though it&#8217;s pushing the second box away.

<pre><code class="language-css">
@keyframes margin {

to { margin-right: 7rem; }

}

.margin {

display: inline-block;

height: 5rem;

width: 5rem;

background-color: lightblue;

vertical-align: top;

}

.margin:first-of-type {

margin-right: 0;

animation: margin 4s ease 0s infinite;

}
</code></pre>

### Padding

  * Accepts 1 to 4 non-negative values
  * If you use 4 values, the first value is the top margin and the rest follow in a clockwise fashion
  * Initial value: 0

Padding is the space between the content and the border of an element. In the demo (#2),  it shows a box in which its padding is increasing.

<pre><code class="language-css">
@keyframes padding {

to { padding: 2rem; }

}

.padding {

display: inline-block;

padding: 0;

background-color: lightgreen;

animation: padding 2.5s ease 0s infinite;

}
</code></pre>

### Height

  * Accepts a non-negative number, this number is overridden however by (min/max)-height
  * Initial value: auto

&#8220;Height&#8221; is the height of an element without its <span><span> padding, border, or margin. In the demo (#3) you can see the boxes&#8217; height shrink, and each box begins it&#8217;s animation at a different time. </span></span>

<pre><code class="language-css">
@keyframes height {

to { height: .01rem; }

}

.height {

display: inline-block;

height: 4rem;

width: 3rem;

background-color: violet;

animation: height 1.25s ease 0s infinite;

vertical-align: top;

}

.height:nth-of-type(n) {

animation: height 1.25s ease .2s infinite alternate;

}

.height:nth-of-type(2n) {

animation: height 1.25s ease .4s infinite alternate;

}

.height:nth-of-type(3n) {

animation: height 1.25s ease .6s infinite alternate;

}
</code></pre>

### Width

  * Accepts a non-negative number, this number is overridden however by (min/max)-width
  * Initial value: auto

&#8220;Width&#8221; is the width of an element without its <span><span> padding, border, or margin. In the demo (#4), it is similar to #3, however, it&#8217;s the width being affected as opposed to the height. </span></span>

<pre><code class="language-css">
@keyframes width {

to { width: .01rem; }

}

.width {

margin-bottom: .2rem;

height: 3rem;

width: 6.5rem;

background-color: bisque;

}

.width:nth-of-type(n) {

animation: width 1.25s ease .2s infinite alternate;

}

.width:nth-of-type(2n) {

animation: width 1.25s ease .4s infinite alternate;

}

.width:nth-of-type(3n) {

animation: width 1.25s ease .6s infinite alternate;

}

</code></pre>

### Conclusion

And so with this we can add another collection of animations to our toolbelt! If you&#8217;re wondering why I left border out of this box-model post, it&#8217;s because I have already written a post dedicated to just the [border animation](https://brandonrozek.com/2015/05/animatable-border/). Here are some of the resources I looked at for this post. Hopefully I&#8217;ll come back with another animatable post soon! <https://developer.mozilla.org/en-US/docs/Web/CSS/margin> <https://docs.webplatform.org/wiki/css/properties/margin>{.broken_link} <https://developer.mozilla.org/en-US/docs/Web/CSS/padding> <https://docs.webplatform.org/wiki/css/properties/padding>{.broken_link} <https://developer.mozilla.org/en-US/docs/Web/CSS/height> <https://docs.webplatform.org/wiki/css/properties/height>{.broken_link} <https://developer.mozilla.org/en-US/docs/Web/CSS/width> <https://docs.webplatform.org/wiki/css/properties/width>{.broken_link}