* {
  box-sizing: border-box;
}

body {
  transition: all 0.5s ease;
  margin: 0;
  padding: 0;
  font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
  background-attachment: fixed;
  background-size: cover;
}

header {
  display: block;
  position: fixed;
  z-index: 999;
}

.main-header {
  width: 100%;
  top: 0px;
  left: 0px;
  position: fixed;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0px 10px;
  z-index: 100;
  background-color: white;
}

.main-header .web-name {
  font-size: 1.7rem;
  flex-basis: 20%;
  position: relative;
  color: brown;
  font-weight: bold;
}

.main-header .top-nav {
  position: relative;
  padding: 0px;
  flex-basis: 60%;
  text-align: left;
}

.main-header .top-nav a {
  color: black;
  text-decoration: none;
  font-size: 1.15rem;
  padding: 7.5px;
  display: inline-block;
  margin-right: 10px;
  font-weight: bold;
  margin-top: 5px;
}

.top-nav a:hover {
  background-color: lightgray;
  color: brown;
}

#toggler {
  font-size: 1.4rem;
  color: black;
  padding: 5px;
  border: 2px solid #333;
  display: none;
  font-weight: bold;
}

.start-button {
  flex-basis: 20%;
  align-items: center;
}

.start-button .top-getstarted {
  color: white;
  font-weight: bold;
  font-size: 1rem;
  background-color: brown;
  border: none;
  padding: 10px;
  border-radius: 20px;
}

.start-button .top-getstarted:hover {
  box-shadow: 2px 2px 10px brown;
}

.home-content{
  margin: 150px 20% 0% 20%;
  background-color: rgba(0, 0, 0, 0.1);
  padding: 50px 10px 20px 10px;
  text-align: center;
  font-weight: bold;
}

.home-content h1{
  color: black;
  font-size: 3rem;
  border-bottom: 5px dashed orange;
}

.main-content{
  margin: 120px 20% 20px 20%;
  background-color: rgba(0, 0, 0, 0.1);
  padding: 50px 10px 20px 10px;
  text-align: left;
  font-weight: bold;
}

.main-content h1{
  font-size: 2rem;
  color: black;
  border-bottom: 3px dashed orange;
}

.main-content h2{
  color: black;
}

.main-content li, .main-content a.details, .main-content #subject-link{
  margin-bottom: 30px;
}

.main-content li a, .main-content a.details, .main-content #subject-link{
  padding: 7.5px 10px;
  line-height: 40px;
  text-decoration: none;
  color: black;
  background-color: goldenrod;
  border-radius: 20px;
}

.main-content li a:hover, .main-content a.details:hover, .main-content #subject-link:hover{
  background-color: brown;
}

.getstarted{
  color: white;
  font-weight: bold;
  font-size: 1rem;
  background-color: brown;
  border: none;
  padding: 10px;
  border-radius: 20px;
  margin-top: 50px;
}

#previous-btn, #next-btn{
  color: white;
  font-weight: bold;
  font-size: 1rem;
  background-color: brown;
  border: none;
  padding: 10px;
  border-radius: 20px;
}

.getstarted:hover, #previous-btn:hover, #next-btn:hover{
  box-shadow: 1px 1px 10px black;
}

.nav-buttons{
  width: 100%;
}

#next-btn{
  float: right;
}

.row{
  margin-top: 100px;
  padding: 10px;
  text-align: left;
  color: white;
  font-weight: bold;
}

.row h1{
  margin: 0px 10px;
  color: black;
}

.row h2, h3{
  color: brown;
}

.row .left-col{
  width: 20%;
  display: block;
  padding-top: 46px;
  position: fixed;
}

.row .left-col a{
  color: white;
  display: block;
  text-align: center;
  text-decoration: none;
  font-weight: bold;
  background-color: #444;
  padding: 10px;
  font-size: 1rem;
  border-bottom: 2px solid white;
}

.row .left-col a:hover{
  background-color: brown;
}

.row .main-col{
  float: right;
  width: 80%;
}

.row .left-col ol{
  list-style-type: none;
}

.row .main-col .subject-content{
  width: 100%;
  margin-left: 10px;
  color: black;
}

.row .main-col .subject-content p{
  color: black;
}

#domreader{
  width: 100%;
  height: 80vh;
}

.dropdown {
  top: 80px;
  right: 10px;
  width: 20%;
  display: none;
  padding-top: 10px;
  position: fixed;
}

.dropdown a{
  color: white;
  display: block;
  text-align: center;
  text-decoration: none;
  font-weight: bold;
  background-color: #444;
  padding: 10px;
  font-size: 1rem;
  border-bottom: 2px solid white;
}

.dropdown a:hover{
  background-color: brown;
}

@media only screen and (max-width: 1024px){
  body h1, h2, h3{
    font-size: 1rem;
  }

  .row{
    margin-top: 30px;
  }

  .row .left-col{
    width: 100%;
    display: block;
    position: relative;
  }
  
  div.left-col a{
    color: white;
    float: left;
    text-align: center;
    text-decoration: none;
    background-color: #444;
    padding: 10px;
    width:25%;
  }

  .row .main-col{
    width: 100%;
  }

  .row h1{
    margin-top: 10px;
  }

  .top-nav a:nth-child(n+6):nth-child(-n+11){
    display: none;
  }

  .top-getstarted{
    display: none;
  }

  .dropdown.responsive {
    top: 80px;
    right: 10px;
    width: 30%;
    display: block;
    padding-top: 10px;
    position: fixed;
  }

  .dropdown.responsive a{
    width: 100%;
  }
  
  #toggler{
    display: block;
  }

  .home-content{
    margin-left: 15%;
    margin-right: 15%;
  }

  .main-content a#subject-link{
    font-size: 14px;
  }
}

@media only screen and (max-width: 768px){
  .web-name{
    display: none;
  }
  
  body h1{
    font-size: 1rem;
  }

  .row .left-col{
    padding: 0px;
    width: 100%;
    display: block;
    position: relative;
  }
  
  .row .left-col a{
    color: white;
    display: inline-block;
    text-align: center;
    text-decoration: none;
    font-weight: bold;
    background-color: #444;
    padding: 7.5px;
    font-size: 1rem;
    width:24%;
  }

  .row .main-col{
    width: 100%;
  }

  .row h1{
    margin-top: 20px;
  }

  .row h2{
    margin-top: 20px;
  }

  .top-nav a:nth-child(n+4):nth-child(-n+11){
    display: none;
  }

  .top-getstarted{
    display: none;
  }

  .dropdown.responsive {
    top: 80px;
    right: 10px;
    width: 30%;
    display: block;
    padding-top: 10px;
    position: fixed;
  }
  
  .dropdown.responsive a{
    width: 50%;
  }

  #toggler{
    display: block;
  }

  .home-content{
    margin-left: 10%;
    margin-right: 10%;
  }

  .main-content a#subject-link{
    font-size: 16px;
  }
}

@media only screen and (max-width: 480px){
  
  .web-name{
    display: none;
  }

  .main-header{
    padding: 10px 0px;
  }
  
  body h1{
    font-size: 1rem;
  }

  .row .left-col{
    padding: 0px;
    width: 100%;
    display: block;
    position: relative;
  }
  
  .row .left-col a{
    color: white;
    display: inline-block;
    text-align: center;
    text-decoration: none;
    font-weight: bold;
    background-color: #444;
    padding: 5px;
    font-size: 1rem;
    width:24%;
  }

  .row .main-col{
    width: 100%;
  }

  .row h1{
    margin-top: 20px;
  }

  .top-nav a:nth-child(n+2):nth-child(-n+11){
    display: none;
  }

  .top-getstarted{
    display: none;
  }

  .dropdown.responsive {
    top: 80px;
    right: 10px;
    width: 100%;
    display: block;
    padding-top: 10px;
    position: fixed;
  }

  .dropdown.responsive a{
    width: 100%;
  }
  
  #toggler{
    display: block;
  }

  .home-content, .main-content{
    margin-top: 100px;
    margin-left: 5%;
    margin-right: 5%;
    height: 100vh;
  }

  .main-content h1{
    font-size: 1.5rem;
  }

  .home-content h1{
    font-size: 1.8rem;
  }

}