body {
    width: 100%;
}

body>header {
    grid-template-columns: 1fr;
    grid-template-rows: 100px;
    grid-template-areas: 'menu' ;
}

body>header>span {
    display: none;
}

body>header>nav {
    justify-content: center;
    margin-right: 0px;
}

body>header>div {
    display: none;
}

body>header>nav>ul li a {
    margin: 5px;
}

body main {
    grid-template-columns: 1fr;
    padding-left: 15px;
    padding-right: 15px;
}

.caja50 {
    grid-column: span 1;
    padding: 15px;
}

.caja33 {
    grid-column: span 1;
    padding: 15px;
    font-size: 1em;

}