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

body{
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: #333333;
    line-height: 1.6;
}

/* barra del menu */
.encabezado-principal{
    background-color: #00897b;
    padding: 10px 5%;
}
.menu-nav ul{
    list-style: none;
    display: flex;
    gap: 25px;
}
.menu-nav a{
    text-decoration: none;
    color: #ffffff;
    font-weight: 600;
    font-size: 1.2rem;
    display: inline-block;
    padding: 5px 10px;
    transition: color 0.3s ease;
}

/* cursor encima: azul */
.menu-nav a:hover{
    color: #0000ff;
}

/* al hacer clic: rojo */
.menu-nav a:active{
    color: #ff0000;
}

main{
    width: 100px;
    height: 500px;
    border: 10px solid gray;
    padding: 20px 35px;
}
/*Diseño Responsive*/
@media(max-width:768px){
    .menu-nav ul{
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }
}