Twitter bird CTA animation with CSS3 + a bouncing logo and rolling link btn

index.html

<div class="container">
  <div class="twitter-bird step"></div>
</div>

<div class="container">
  <div class="logo"></div>
</div>

<div class="container">
  <div class="button">
    <span class="label">Button</span>
    <span class="label">Button</span>
  </div>
</div>

script.js

// NO JAVASCRIPT

style.css

body {
  font-family: "Helvetica Neue", Arial, sans-serif;
	font-size: 30px;
	font-weight: 300;
  height: 100%;
  margin: 0;
  padding: 0;
  position: relative;
}

* {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  -ms-box-sizing: border-box;
  box-sizing: border-box;
}

.container {
  display: inline-block;
  float: left;
  height: 240px;
  margin: -120px 0 0;
  padding: 0;
  position: relative;
  text-align: center;
  top: 50%;
  width: 33.33%;
}


/* Twitter Bird */

.twitter-bird {
	background-image: url(http://minimalmonkey.com/lab/css3-animations/twitter-bird-sprite.png);
	cursor: pointer;
	display: inline-block;
	height: 150px;
  margin: 50px -30% 0 0;
	width: 150px;
}

.twitter-bird:hover {
	-webkit-animation: fly 0.2s steps(3) 0 infinite;
	-moz-animation: fly 0.2s steps(3) 0 infinite;
	animation: fly 0.2s steps(3) 0 infinite;
}

@-webkit-keyframes fly {
	from { background-position: 0 0; }
    to { background-position: -450px 0; }
}
@-moz-keyframes fly {
	from { background-position: 0 0; }
    to { background-position: -450px 0; }
}
@keyframes fly {
	from { background-position: 0 0; }
    to { background-position: -450px 0; }
}

/* Logo */

.logo {
	background-image: url(http://minimalmonkey.com/lab/css3-animations/logo.png);
	background-repeat: no-repeat;
	cursor: pointer;
  display: inline-block;
	height: 150px;
	margin: 50px 50px 0;
	width: 154px;
}

.logo:hover {
	animation-name: bounce;
	animation-duration: 0.5s;
	animation-timing-function: linear;
	animation-iteration-count: 1;

	-moz-animation-name: bounce;
	-moz-animation-duration: 0.5s;
	-moz-animation-timing-function: linear;
	-moz-animation-iteration-count: 1;

	-webkit-animation-name: bounce;
	-webkit-animation-duration: 0.5s;
	-webkit-animation-timing-function: linear;
	-webkit-animation-iteration-count: 1;
}

@-webkit-keyframes bounce {
	45% {
		height: 130px;
		margin-top: 70px;
	}
	55% {
		height: 130px;
		margin-top: 70px;
	}
	75% {
		height: 170px;
		margin-top: 0px;
	}
}
@-moz-keyframes bounce {
	45% {
		height: 130px;
		margin-top: 70px;
	}
	55% {
		height: 130px;
		margin-top: 70px;
	}
	75% {
		height: 170px;
		margin-top: 0px;
	}
}
@keyframes bounce {
	45% {
		height: 130px;
		margin-top: 70px;
	}
	55% {
		height: 130px;
		margin-top: 70px;
	}
	75% {
		height: 170px;
		margin-top: 0px;
	}
}

/* Button */
.button {
	background-color: #26bf4a;
	color: white;
	cursor: pointer;
	display: inline-block;
	height: 60px;
	letter-spacing: 2px;
	line-height: 60px;
  margin: 90px 0 0 -20%;
	min-width: 220px;
	overflow: hidden;
	position: relative;
	text-align: center;
	text-transform: uppercase;
	-webkit-transition: background-color 0.35s;
  -moz-transition: background-color 0.35s;
  transition: background-color 0.35s;
}

.label {
	display: block;
	height: 100%;
	padding: 0 40px;
	position: relative;
	top: 0%;
  -webkit-transition: top 0.35s;
  -moz-transition: top 0.35s;
  transition: top 0.35s;
  width: 100%;
}

.button:hover {
	background-color: #1d9f3b;
}

.button:hover .label {
	top: -100%;
}