nav li {
  border: 3px solid grey;
  list-style: none;
  flex-grow:1;
  background-color: black;
}
ul {
  display: flex;
  flex-direction: row;
}
a {
  display: block;
  text-align: center;
  text-decoration: none;
  color: white;
}
nav li{
  box-shadow: 8px 8px 6px #333333;
}
nav li:hover{
  box-shadow: 8px 8px 6px #333333;
  -webkit-transition-property: box-shadow;
  -webkit-transition-duration: 5s;
  -webkit-transition-delay:1s;
}
nav {
  background-image: url(../img/gotas.jpg);
  height: 50px;
}
.arriba {
  background-image: url(../img/gotas.jpg);
}
footer {
  background-image: url(../img/gotas.jpg);
  float: left;
  width: 100%;
}
div {
   width: 100%;
   background-color: purple;
   color: white;
   font-family: Arial;
   font-size: 16px;
}
.izquierda {
  float: left;
  width: 80%;
  height: 100%;
}
.derecha {
  float: right;
  width: 20%;
  height: 100%;  
}
#derecha {
  float: right;
  width: 20%;
  height: 100%;  
}
h1 {
  text-decoration: underline;
}