html,
body {
  min-width: 300px;
  color: black;
  background-color: #eee;
  font-size: 20px;
  line-height: 1.5;
}

header {
  margin: 10px;
  text-align: center;
  font-size: 2em;
  font-weight: bold;
}

#navbar {
  position: fixed;
  top: 0px;
  left: 0px;
  width: 300px;
  height: 100%;
  border-right: solid;
  border-color: gray;

}

#navbar ul {
  height: 80%;
  padding: 0;
  overflow-y: auto;
  overflow-x: hidden;

}

#navbar li {

  border-top: 1px solid;
  list-style: none;
  position: relative;
  width: 100%;
}

#navbar a {
  display: block;
  padding: 10px 30px;
  color: black;
  text-decoration: none;
}

#main-doc {
  position: relative;
  margin-left: 310px;
  padding: 20px;
    margin-bottom: 100px;
}


#main-doc header {
  text-align: left;
  margin: 0px;
  font-size: 1.7em;
}

section article {
  margin: 15px;
  font-size: .95em;
}

h2 {
  font-size: 2em;
  
}

samp {
  display: block;
  text-align: left;
  white-space: pre-line;
  position: relative;
  word-break: normal;
  word-wrap: normal;
  line-height: 1.5;
  background-color: white;
  color: darkred;
  padding: 15px;
  margin: 10px;
}

code {
  color: red;
  font-size: .9em;
}

/* responsive ui design */
@media only screen and (max-width: 800px) {
  #navbar ul {
 padding: 0;
    height: 180px;
  }

  #navbar {
    position: absolute;
    top: 0;
    padding: 0;
    margin: 0;
    width: 100%;
    max-height: 275px;
    border: none;
    border-bottom: 2px solid;
  }

  #main-doc {
    position: relative;
    margin-left: 0px;
    margin-top: 275px;
  }
  
  img {
    width: 90%;
  }
}