body{
  margin: 0;
  font-family: sans-serif;
}

#container {
  width: 100vw;
  height: 100vh;
  background-color: #fff;
  overflow: hidden;
}    
.col {
  width: 30vw;
  height: 100%;
  float: left;
}

#col1 {
  background-color: #ff7777;
}

#col2 {
  width: 40vw;
  background-color: #77ff77;
}

#col3 {
  background-color: #7777ff;
}

#header {
  height: 10vh;
  padding: 0px;
  padding-bottom: 21px;
  padding-left: 21px;
  border-bottom: 1px solid;
  box-shadow: 0px 11px 11px -11px rgba(0,0,0,0.75);
  background-color: #05568d;
  color: #fff;
}

.content {
  height: 90vh;
  display: none;
  font-size: 4vh;
  padding-left: 5vh;
}

.page-btn {
  width: 7%;
  height: 100%;
  border: none;
  background: none;
  border-top: 2px solid #eee;
  cursor: pointer;
}

.page-btn:focus {
  border: none;
  border-top: 7px solid #eee;
  outline: none;
}

.active {
  border: none;
  outline: none;
  display: block;
}

.heading {
  font-size: 5vh;
  font-weight: bold;
  padding: 10px;
  font-style: italic;
  margin-right: 5vw;
  cursor: pointer;
}

pre {
  margin: 0;
}

b {
  text-shadow: 0px 0px 1px #05568d;
  color: #05568d;
}

b:hover {
  color: #FF6961;
}

#tools {
  position: fixed;
  bottom: 10px;
  right: 10px;
}

h1 {
  font-size: 50vh;
}

#myBox {
  background-color: green;
  position: absolute;
  padding: 10px;
  color: #fff;
  font-weight: bold;
  cursor: pointer;
}  

#myBox:hover {
  background-color: lime;
}

#roundDiv {
  background-color: blue;
  width: 200px;
  height: 200px;
  border-radius: 50%;
}

#roundDiv:hover {
  background-color: yellow;
}

.answer-box {
  color: #9e9e9e;
  opacity: 0.2;
  position: absolute;
  bottom: 0;
}

.answer-box:hover {
  color: #000;
  opacity: 1;
}

.answer-box h3{
  color: red;
}

.answer-box pre{
  opacity: 0.1;
}

.answer-box pre:hover{
  opacity: 0.5;
}