general.css

.nav-bar {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: gray;
  display: block;
  float: left;
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
}

.nav-bar-tab {
  float: left;
}

.nav-bar-tab:hover {
  background-color: darkgray;
  box-shadow: 0 0 10px lightskyblue;
}

.active {
  background-color: rgb(100, 100, 100);
  font-weight: bold;
}

.nav-bar-tab a {
  display: block;
  color: white;
  text-align: center;
  padding: 12px 50px;
  text-decoration: none;
  font-family: Verdana, monospace;
  font-size: 1.5em;
  text-shadow: 0px 0px 1px black, 0px 0px 10px lightskyblue;
  font-variant: small-caps;
}

.myelement {
  background-color: red;
}

#content {
  font-family: Verdana;
  border-radius: 15px;
  background: lightgray;
  border: 3px solid gray;
  padding: 10px;
  width: 100%;
  height: 200px;
}

body {
  margin-top: 100px;
}