/* Import the Google Font 'Open Sans' */
@import url(http://fonts.googleapis.com/css?family=Open+Sans);


/* All widths and heights are calculated using the border box */
*,
*::before,
*::after {
  box-sizing: border-box;
}

/* Positioning and layout of containers */
body {
  background-color: #FFFFFF;
  top:0px;
}

.container {
  font-family: Open Sans, Helvetica, Arial, sans-serif;
  font-size: 16px;
  width: 900px;
  top:0px;
  height: 550px;
  padding: 25px 50px;
  margin: 50px auto;
  box-shadow: 1px 1px 1px 1px rgba(100, 100, 100, 0.25);
  background-color: white;
}

.tabs {
  list-style: none;
  padding: 0;
  width: 950px;
  margin: 0 auto;
}

.tab-item {
  display: inline-block;
  margin-left: -5px;
}

.tab {
  position: absolute;
}

.tab > input[type=radio] {
  opacity: 0;
  position: absolute;
  top: 0;
  left: 0;
  width: 150px;
  height: 50px;
  margin: 0;
  background-color: transparent;
  outline: none;
  z-index: 1;  
}

.label {
  display: inline-block;
  position: absolute;
  top: 0;
  left: 0;
  width: 150px;
  margin: 0;
  border-left: 1px solid rgba(100, 100, 100, 0.5);
  text-align: center;
  line-height: 50px;
  background-position: 0 3px;
  background-repeat: no-repeat;
  background-size: 25px;
  transition: background-position 250ms, color 250ms;
  z-index: 0;
}

.label::before {
  content: '';
  position: absolute;
  top: 0;
  left: -1px;
  width: 150px;
  height: 3px;
}

.label::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 147px;
  height: 2px;
  background-color: transparent;
}

.tabs .tab-item:last-child .label::after {
    width: 146px;
}

/* In Firefox some width values need to be slightly different */
@-moz-document url-prefix() {
  .label::before {
    width: 155px;
  }
  
  .label::after {
    width: 152px;
  }
  
  .tabs .tab-item:last-child .label::before {
    width: 150px;
  }
  
  .tabs .tab-item:last-child .label::after {
    width: 146px;
  }
}
/* END Positioning and layout of containers */


/* Colors, graphics and positioning for tabs */
/*.label.orange {
  background-image: url(https://dl.dropboxusercontent.com/s/68gv23q4y5qyq52/html5.svg);
}*/

.label.blue {
  background-image: url(https://dl.dropboxusercontent.com/s/gftbpqje9h2jvlv/css3.svg);
}

.label.yellow {
  background-image: url(https://dl.dropboxusercontent.com/s/jsp3rsberc4q650/javascript.svg);
}

.label.green {
  background-image: url(https://dl.dropboxusercontent.com/s/v28zws1p38tjph2/node.png);
}

.label.orange::before {
  background-color: #e34f26;
}

.label.blue::before {
  background-color: #0d84ce;
}

.label.yellow::before {
  background-color: #f0e040;
}

.label.green::before {
  background-color: #83cd29;
}

.tabs .tab-item:last-child .label {
  border-right: 1px solid rgba(100, 100, 100, 0.5);;
}

.tabs .tab-item:nth-child(2) input[type=radio],
.tabs .tab-item:nth-child(2) .label{
  left: 150px;
}
.tabs .tab-item:nth-child(2) .tab-content {
  left: 1px;
}

.tabs .tab-item:nth-child(3) input[type=radio],
.tabs .tab-item:nth-child(3) .label{
  left: 300px;
}

.tabs .tab-item:nth-child(3) .tab-content {
  left: 2px;
}

.tabs .tab-item:nth-child(4) input[type=radio],
.tabs .tab-item:nth-child(4) .label{
  left: 450px;
}

.tabs .tab-item:nth-child(4) .tab-content {
  left: 3px;
}

.tab > input[type=radio]:checked ~ .label::after {
  background-color: white;
}

.tab > input[type=radio]:checked ~ .label {
  color: #975997;
  background-position: 12.5px 50%;
}

.tab > input[type=radio]:checked ~ .label.orange {
  color: #e34f26;
  background-image: url(https://dl.dropboxusercontent.com/s/68gv23q4y5qyq52/html5.svg);
}

.tab > input[type=radio]:checked ~ .label.blue {
  color: #0d84ce;
}

.tab > input[type=radio]:checked ~ .label.yellow {
  color: #f0e040;
}

.tab > input[type=radio]:checked ~ .label.green {
  color: #83cd29;
}

.tab > input[type=radio]:checked ~ .tab-content p {
  top: 0;
}

.tab > input[type=radio]:not(:checked) ~ .tab-content p {
  top: 300px;
}

.tab-content {
  position: absolute;
  top: 50px;
  width: 810px;
  height: 270px;
  padding: 0 20px;
  overflow: hidden;
}

.tabs .tab-item:first-child .tab-content{
  border: 1px solid rgba(100, 100, 100, 0.5);;
}

.tab-content p {
  position: relative;
  top: 300px;
  transition: top 500ms;
}
/* END Colors, graphics and positioning for tabs */