*{
    margin:0;
    padding: 0;
    box-sizing: border-box;
}


.main-nav{
    margin-top: 10px;
    list-style: none;
    padding-left: 0;
    background-color: #008489;
}

.main-nav-item{
    display: inline-block;
    border-right: 3px solid #ffffff;
}

.main-nav-item a{
    color: white;
    padding: 2px 8px;
    text-decoration: none;
    border-radius: 2px;
    /*background-color: red;*/
}

.main-nav-item a:hover{
    color: blue;
}

.main-nav-item a:active{
    color: chocolate;

}

main{
    width: 100;
    height: 500px;
    border: 10px solid gray;
    padding: 20px 35px;
}

/* menú desplegable */
.dropdown {
    position: relative;
}

.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 260px;
    list-style: none;
    background-color: #008489;
    border-top: 3px solid #ffffff;
    z-index: 100;
}

.dropdown-content li {
    display: block;
}

.dropdown-content a {
    display: block;
    padding: 10px 12px;
    border-bottom: 1px solid #ffffff;
}

.dropdown-content a:hover {
    background-color: #006b70;
}

.dropdown:hover .dropdown-content,
.dropdown:focus-within .dropdown-content {
    display: block;
}