body {
  background:#aaa;
  font-family: Arial;
  top: 0;
  left: 0;
}

a {
  text-decoration: none;
  color: white;
  -moz-transition-duration: 0.5s;
  -webkit-transition-duration: 0.5s;
  -o-transition-duration: 0.5s;
}

a:hover {
  color: black;
  -moz-transition-duration: 0.5s;
  -webkit-transition-duration: 0.5s;
  -o-transition-duration: 0.5s;
}

#container {
  top:15vh;
  left:25vw;
  position: absolute;
  width: 800px;
  height: 500px;
  background: purple;
  padding: 5px;
}

#sidebar {
  position: absolute;
  width: 200px;
  height: 490px;
  padding: 5px;
  background: pink;
}

#content {
  position: relative;
  width: 70%;
  height: 480px;
  margin-left: 225px;
  padding: 5px;
  overflow-y: auto;
}

ul#tabs {
  list-style-type: none;
  padding: 5px;
  text-align: center;
}

ul#tabs li {
  display: inline-block;
  width: 75px;
  margin: 5px;
  padding: 5px;
  background: white;
  color: black;
  -moz-transition-duration: 0.5s;
  -webkit-transition-duration: 0.5s;
  -o-transition-duration: 0.5s;
}

ul#tabs li:hover {
  background: black;
  color: white;
  -moz-transition-duration: 0.5s;
  -webkit-transition-duration: 0.5s;
  -o-transition-duration: 0.5s;
}

ul#tabs .active {
  background: black;
  color: white;
}

ul#tab {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

ul#tab li {
  display: none;
}

ul#tab .active {
  display: block;
}