ul {
    list-style-type: none;
    margin-top: -1em;
    margin-left: -0.5em;
    margin-bottom: 0;
    font-family: "Sans-serif", Arial, serif;
    font-size: 1.3em;
    font-weight: bold;
    overflow: hidden;
    
 background:
    linear-gradient(black,white
    )
    left
    bottom
    rgb(235,28,36)  
    no-repeat; 
  background-size:100% 14px ;

   padding-bottom:5px;

}
#letrero {
    margin-top: -1em;
    margin-left: -1em;
    margin-right: -1em;
}
li {
    float: left;
}

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

li a:hover {

    background-color: white;
    color: red;
}