body {font-family: Arial;font-size: 0.9em;}
nav li {display: inline;}
nav ul {
  border-top   : 1px solid black;
  border-bottom: 1px solid black;
  display      : flex;
  list-style   : none;
  margin-top   : 0px;
  margin-bottom: 20px;
  padding-left : 20px;
  margin-left  : 0px;
  background-color: silver;
}
nav ul li {
  display : block;
  position: relative;
  float   : left;
  padding-left : 5px;
  padding-right: 5px;
  line-height  : 20px;
  text-align   : center;
  background-color: silver;
}
nav ul li ul {
  position: absolute;
  display: none;
  background-color: silver;
  left: 0px;
  padding-left: 0px;
}
nav ul li:hover    {background:#09c; color:#fff;}
nav ul li:hover ul {display: block;left:0;}
nav ul li ul li    {white-space:nowrap;}
nav ul li a {
  text-decoration: none;
  display: block;
  padding: 5px;
}

@media screen and (min-width:768px) and (max-width: 1023px){
  body {font-size: 1.2em}
}
@media screen and (max-width: 767px){
  body {font-size: 1.4em}
}