displayNavbar.css

/*
Block: Top Bottom Margin Respected
Inline: Top Bottom Margin Not Respected
Mobile Navbar
List-style-type: property
descendant selectors
*/
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: Verdana, Geneva, Tahoma, sans-serif;
}
ul li {
  list-style-type: none;
}
ul li a {
  text-decoration: none;
  text-transform: capitalize;
  letter-spacing: 2px;
  background: #222;
  color: #f150f1;
  display: block;
  padding: 5px 5px;
  margin: 10px 10px;
}
/*
Border-Box
*/
.box-1,
.box-2,
.box-3 {
  width: 200px;
  height: 200px;
  color: white;
}
.box-1 {
  background: red;
}
.box-2 {
  background: blue;
}
.box-3 {
  background: green;
}

/*
display:none
opacity: 0
visibility: hidden
*/
div {
  background: blue;
  margin: 10px;
  color: white;
}
.none {
  display: none;
}
.opacity-1 {
  opacity: 1;
}
.opacity-5 {
  opacity: 0.35;
}
.opacity-0 {
  opacity: 0;
}
.visibility {
  visibility: hidden;
}