navstyling.css

/* Styling for the navigation bar and dropdown */
ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333;
}

li {
  float: left;
}

li a, .dropbtn {
  display: inline-block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

li a:hover :not(#main), .dropdown:hover .dropbtn {
  background-color: red;
}

li.dropdown {
  display: inline-block;
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  /*min-width: 160px;*/
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}

.dropdown-content a {
  color: black;
  padding: 4px 8px;
  text-decoration: none;
  display: block;
  text-align: left;
}

.dropdown-content a:hover {background-color: #f1f1f1;}

.dropdown:hover .dropdown-content {
  display: block;
}

#main {
  font-size: 20px;
  padding: 10px 15px;
}
/* End navigation styling */



/* Styling for the content */
body {
  font-family: "Quantico";
  text-align: center;
}
header {
  text-align: center;
}
h2 {
  text-align: center;
  font-size: 1.2em;
  border-top: 2px dashed yellow;
  border-bottom: 2px dashed yellow;
}
input[type=number] {
  width: 40px;
  height: 40px;
  margin-left: 20px;
  background-color: #DADADA;
  font-size: 1.2em;
}
input[type=submit] {
  width: 200px;
  font-size: 2em;
}
#calculator {
  /*border: 1px solid #dadada;*/
  border-radius: 4px;
  padding: 4px;
  width: 50%;
  padding-left: 25%;
  font-size: .85em;
}
.input-area {
  background-color: #42FF8C;
  padding: 8px;
  margin: 8px;
  text-align: center;
  border-radius: 8px;
}
.operator-choices {
  text-align: left;
}
.output-area {
  background-color: #333333;
  color: #FFFFFF;
  padding: 8px;
  margin: 8px;
  font-size: 1.5em;
}
/* End content styling */