Generated by SassMeister.com.

SassMeister-input-HTML.html

<button class="load-more"></button>

SassMeister-input.sass

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

@import "compass"

$load-more-height: 40px
$load-more-color: #303030
$load-more-text-color: lighten($load-more-color, 35)

.load-more
	display: block
	height: $load-more-height
	width: 75%
	max-width: 280px
	padding: 0
	margin: 0 auto
	background-color: $load-more-color
	border: 2px solid lighten($load-more-color, 3)
	border-radius: 4px
	text-align: center

	&:after
		display: inline-block
		content: 'load more'
		text-transform: uppercase
		font-weight: bold
		font-size: 16px
		line-height: $load-more-text-color
		background: -webkit-gradient(linear, left top, right top, color-stop(0, $load-more-text-color), color-stop(0.05, white), color-stop(0.40, $load-more-text-color), color-stop(1, $load-more-text-color))
		-webkit-background-clip: text
		-webkit-text-fill-color: transparent
		-webkit-animation: slide-to-unlock 5s linear infinite
    
	&:before
		display: inline-block
		height: 13px
		width: 15px
		margin-right: 5px
		content: ''
		background: url('http://f.cl.ly/items/0Z3d3R333U1P0r070627/arrow-icon.png') no-repeat 50%
		background-size: contain

@include keyframes(slide-to-unlock)
	from
		background-position: -300px 0

	to
		background-position: 300px 0

SassMeister-output.css

.load-more {
  display: block;
  height: 40px;
  width: 75%;
  max-width: 280px;
  padding: 0;
  margin: 0 auto;
  background-color: #303030;
  border: 2px solid #383838;
  border-radius: 4px;
  text-align: center;
}
.load-more:after {
  display: inline-block;
  content: "load more";
  text-transform: uppercase;
  font-weight: bold;
  font-size: 16px;
  line-height: #898989;
  background: -webkit-gradient(linear, left top, right top, color-stop(0, #898989), color-stop(0.05, white), color-stop(0.4, #898989), color-stop(1, #898989));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  -webkit-animation: slide-to-unlock 5s linear infinite;
}
.load-more:before {
  display: inline-block;
  height: 13px;
  width: 15px;
  margin-right: 5px;
  content: "";
  background: url("http://f.cl.ly/items/0Z3d3R333U1P0r070627/arrow-icon.png") no-repeat 50%;
  background-size: contain;
}

@-moz-keyframes slide-to-unlock {
  from {
    background-position: -300px 0;
  }

  to {
    background-position: 300px 0;
  }
}
@-webkit-keyframes slide-to-unlock {
  from {
    background-position: -300px 0;
  }

  to {
    background-position: 300px 0;
  }
}
@keyframes slide-to-unlock {
  from {
    background-position: -300px 0;
  }

  to {
    background-position: 300px 0;
  }
}

SassMeister-rendered.html

<button class="load-more"></button>