style.scss

#tree{
  li{
    display: block;
    border:1px solid gray;
    padding:1em;
    cursor:pointer;
    margin-bottom: .5em;
    &:hover{
      background-color: #fafafa;
    }
  }
  ul ul{
    display:none;
  }
  h3,h4{
    margin:0;
    padding:1em;
  }
}
.back{
  //display:none;
  border-radius:100px;
  background-color:gray;
  color:white;
  text-transform: uppercase;
  font-size: .75em;
  padding:.5em;
}
.selectedAnswer{
  //color:red;
  &>ul{
    display:block !important;
  }
  & li{
    //color:black;
  }

}
.selectedChild{
  //color: green !important;
  //border:2px solid green !important;
}
.notSelected{
  //color:blue;
  display: none !important;
  opacity:.5;
}
// Classes
.show {
  display: block !important;
}
.hidden {
  display: none !important;
}
.invisible {
  visibility: hidden;
}

body {
  font: 16px/1.5 verdana, helvetica-neue, helvetica, arial, san-serif;
  background: black;
  color: #ececec;
  padding: 0;
  margin: 0;
}
ul {
  margin: 0;
  padding: 0;
}
a {
  color: #ccc;
  text-decoration: none;
}
 
a:hover {
  color: #ececec;
  text-decoration: underline;
}
 
#main {
  width: 960px;
  margin: 0 auto;
  background: rgba(255, 255, 255, 0.4);
}
header {
  padding: 0 10px;
  overflow: hidden;
}
h1 {
  margin: 0;
}
 
nav ul, ul.entries {
  list-style-type: none;
}
nav li a {
  float: left;
  margin: 5px; 
}
.content {
  padding: 10px;
}
 
ul.entries li {
  position: relative;
  margin: 20px auto;
  padding: 20px;
  background: #ececec;
  width: 600px;
}
 
ul.entries img {
  width: 600px;
}
 
ul.entries li h3 {
  position: absolute;
  bottom: -18px;
  left: 17px;
  font-size: 2em;
}
ul.entries a {
  color: #ececec;
}
ul.entries a:hover {
  color: #fff;
}
 
footer {
  font-size: 0.65em;
  text-align: center;
}