reactjs_koans/build/stylesheets/tabs.css

.tabs input[type=radio] {
  position: absolute;
  top: -9999px;
  left: -9999px;
}
.tabs {
  width: 80%;
  position: relative;
  padding: 0;
  margin: 40px auto;
}
.exercise{
  float: left;
  padding-top: 5px;
  margin-right: 3px;
}
ul.tabs>li {
  list-style-type: none;
}
.tabs label {
  display: block;
  padding: 10px 20px;
  border-radius: 2px 2px 0 0;
  color: white;
  font-size: 15px;
  font-weight: normal;
  background: #C41D47;
  cursor: pointer;
  position: relative;
  top: 3px;
  -webkit-transition: all 0.2s ease-in-out;
  -moz-transition: all 0.2s ease-in-out;
  -o-transition: all 0.2s ease-in-out;
  transition: all 0.2s ease-in-out;
}
.tabs label:hover {
  background: #444444;
  top: 0;
}

[id^=tab]:checked + label {
  background: #444444;
  color: white;
  top: 0;
}

[id^=tab]:checked ~ [id^=tab-content] {
  display: block;
}
.tab-content{
  z-index: 2;
  display: none;
  text-align: left;
  width: 100%;
  font-size: 20px;
  line-height: 140%;
  padding-top: 10px;
  background: #AB1C40;
  padding: 12px;
  color: white;
  position: absolute;
  top: 53px;
  margin-top: 50px;
  left: 0;
  box-sizing: border-box;
  -webkit-animation-duration: 0.5s;
  -o-animation-duration: 0.5s;
  -moz-animation-duration: 0.5s;
  animation-duration: 0.5s;
}
.tab-content ul li {
  cursor: pointer;
}
.tab-content ul li.selected {
  color: #444444;
}
.tab-content ul li.completed {
  color: #440000;
  text-decoration: line-through;
}
@media (min-width: 1565px) {
  .tab-content{
    top:0px;
    margin-top:53px;
  }
}
@media (max-width: 840px) {
  .tab-content{
    top:0px;
    margin-top:153px;
  }
}
@media (max-width: 653px) {
  .tab-content{
    top:0px;
    margin-top:203px;
  }
}
@media (max-width: 443px) {
  .tab-content{
    top:0px;
    margin-top:353px;
  }
}