* {
    margin:0;
    padding:0;
}
 
/*EN EL VIDEO HAY UN ERROR POR EL CUAL NO SE VISUALIZA EN GOOGLE CHROME,
EL CÓDIGO A CONTINUACIÓN YA ESTA CORREGIDO*/
 
header {
    margin-top:10px;
    width: 100%;
    overflow: hidden;
    height: 150px;
    position: relative;
}
 
nav {
    top:-20px;
    position: absolute;
    left:0;
    right:0;
    margin:20px auto;
    max-width:1000px;
    width:90%;
}
 
nav ul {
    list-style:none;
}
 
nav > ul {
    display:table;
    /*Quitamos el overflow hidden que estaba aqui*/
    width:100%;
    background:#000;
    position:relative;
}
 
nav > ul li {
    display:table-cell;
}
 
/*Sub-menu*/
nav > ul > li:hover > ul {
    display:block;
    height:100%;
}
 
nav > ul > li > ul {
    display:block;
    position:absolute;
    background:#000;
    left:0;
    right:0;
    overflow:hidden;
    height:0%;
    -webkit-transition: all .3s ease;
    -moz-transition: all .3s ease;
    -ms-transition: all .3s ease;
    -o-transition: all .3s ease;
    transition: all .3s ease;
}
 
nav > ul li a {
    color:#fff;
    display:block;
    line-height:20px;
    padding:20px;
    position: relative;
    text-align:center;
    text-decoration:none;
    -webkit-transition: all .3s ease;
    -moz-transition: all .3s ease;
    -ms-transition: all .3s ease;
    -o-transition: all .3s ease;
    transition: all .3s ease;
}
 
nav > ul > li > ul > li a:hover {
    background:#5da5a2;
}
 
nav > ul > li > a span {
    background:#174459;
    display:block;
    height:100%;
    width:100%;
    left:0;
    position:absolute;
    top:-55px;
    -webkit-transition: all .3s ease;
    -moz-transition: all .3s ease;
    -ms-transition: all .3s ease;
    -o-transition: all .3s ease;
    transition: all .3s ease;
}
 
nav > ul > li > a span .icon {
    display:block;
    line-height:60px;
}
 
nav > ul > li > a:hover > span {
    top:0;
}
 
/*Colores*/
nav ul li a .primero {
    background:#0e5061;
}
 
nav ul li a .segundo {
    background:#5da5a2;
}
 
nav ul li a .tercero {
    background:#f25724;
}
 
nav ul li a .cuarto {
    background:#174459;
}
 
nav ul li a .quinto {
    background:#37a4d9;
}