header{
  background-color: cyan; 
  border: 2px solid black; 
  color: red; 
  font-family: Times New Roman; 
  font-size: 40px; 
  font-stretch: normal; 
  font-variant-east-asian: normal; 
  font-variant-numeric: normal; 
  line-height: normal; 
  margin: 0px; padding: 10px; 
  position: relative; 
  text-align: center;
}
section{
  background-color: pink; 
  border: 2px solid black; 
  font-family: Times New Roman;
  font-size: 13px; 
  line-height: 30px; 
  padding: 15px;
  text-align: justify;
}
h2{
  background-color: yellow; 
  border: 2px solid black; 
  font-family: Times New Roman; 
  font-size: 20px; 
  font-stretch: normal; 
  font-variant-east-asian: normal; 
  font-variant-numeric: normal; 
  line-height: normal; 
  margin: 0px; 
  padding: 20px; 
  position: relative; 
  text-align: center;
}
h1{
	padding:20px;
	text-align:center;
	color: black;
	background-color:yellow;
	border:2px solid black;
}
ol, ul{
  font-family: Times New Roman; 
  font-size: 20px;
}
li{
  margin: 0px 0px 0.25em; 
  padding: 0px;
}
img:hover {
   border: 2px solid blue;
}
img{
    margin: 5px;
    padding: 5px;
}
.responsive {
  max-width: 100%;
  height: auto;
}
section pre{
	border: 2px solid red;
	background-color:white;
	padding:20px;
  overflow: scroll;
  background-color: white; 
  font-size: 20px;
}
.navbar {
  margin-bottom: 0;
  border-radius: 0;
}
.sidenav {
  padding-top: 20px;
  height: 100%;
}
footer{
  background-color: aqua;
  color: black;
  padding: 15px;
  border: 1px solid black;
  width: 64.5%;
}
@media screen and (max-width: 767px) {
  nav{
      display: none;
    }
  .sidenav {
    display: none;
  }
  .row.content {
    height:auto;
    width: 100%;
    padding-top: 0px;
      margin: 0px;
  }  
}
nav{
    position: fixed;
    top: 0;
    left: 0;
    background-color: black; 
    border: 2px solid black;   
    font-size: 40px; 
    margin: 0px; 
    padding: 10px; 
    text-align: center;
    width: 100%;
}
nav ul{
    list-style-type: none;
}
nav ul li{
    float: left;
    margin: 2px;
    padding: 2px;
}
nav ul li a{
    text-decoration: none;
    color: white;
}
.left{
    width: 20%;
}