* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  font-family: Georgia, "Times New Roman", Times, serif;
  font-size: 100%;
  line-height: 1.4;
  height: 100%;
  width: 100%;
  background-color: azure;
  color: black;
}

/*Header*/

#header {
  height: 120px;
  display: flex;
  justify-content: space-around;
  align-items: center;
  border-bottom: 1px solid gray;
}

#header-div {
  display: flex;
  flex-direction: column;
  justify-content: center;
  text-align: center;
  height: 100%;
}

h1 {
  font-size: 28px;
}

#home-link-div {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  height: 100%;
  border-left: 1px solid black;
}

#home-link {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  font-size: 16px;
  height: 80px;
  width: 80px;
  margin: 10px;
  background-color: whitesmoke;
  border-radius: 50%;
}

#home-link:link,
#home-link:visited {
  text-decoration: none;
  color: navy;
}

#home-link:hover {
  text-decoration: underline;
  background-color: gray;
}

.fa-home {
  font-size: 24px;
}

/*Navbar*/

#navbar {
  position: fixed;
  left: 0;
  top: 0;
  height: 100vh;
  width: 25%;
  overflow: auto;
  background-color: white;
  border: 1px solid lightgray;
}

#navbar header {
  font-size: 1.5em;
  font-weight: bold;
  padding: 8px 8px 8px 20px;
  border-bottom: 1px solid gray;
}

#navbar ul {
  list-style-type: none;
  font-size: 1.125em;
}

#navbar ul li {
  height: 100%;
  width: 100%;
  padding: 8px 8px 8px 20px;
  border-top: 1px solid lightgray;
}

.nav-link {
  text-decoration: none;
  color: black;
}

.nav-link:hover {
  text-decoration: underline;
}

/*Main-doc*/

#main-doc {
  position: relative;
  left: 25%;
  width: 75%;
  padding: 20px;
}

.main-section header {
  font-size: 1.5em;
  margin: 40px 0 15px 0;
}

#Introduction header {
  margin-top: 0;
}

.main-section p {
  font-size: 1em;
  margin: 15px 0;
}

.main-section ul {
  margin: 0 0 0 40px;
}

code {
  display: block;
  text-align: left;
  white-space: pre-line;
  line-height: 2;
  padding: 15px;
  margin: 10px;
  border-radius: 5px;
  background-color: #f7f7f7;
}

#Reference {
 margin-bottom: 100px; 
}

/*Media Queries*/

@media (max-width: 700px) {
  body {
    overflow: hidden;
  }

  #navbar {
    position: fixed;
    top: 0;
    left: 0;
    height: 25vh;
    width: 100%;
    text-align: center;
    overflow: auto;
    z-index: 2;
    border: 1px solid lightgray;
  }

  #main-doc {
    position: fixed;
    top: 25vh;
    left: 0;
    height: 75vh;
    width: 100%;
    padding: 20px;
    z-index: 1;
    overflow: scroll;
    border-top: 1px solid black;
  }
}