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

.contenedor {max-width: 60rem; margin: auto; }

    header {width: 100%; background: #efa3e9; height: 10rem; }

    nav { width: 100%; background: #0a1c31; height: 3rem; }

section {background: #a52dd1; display: flex; justify-content: space-around; }

    section .artículo1 {width: 50%; background: #c1d8f0; height: 20rem; margin: 2rem 0.5rem 1rem 1rem; }

    section .artículo2 {width: 50%; background: #c1d8f0; height: 20rem; margin: 2rem 1rem 1rem 0.5rem; }

aside { background: #000; display: flex; justify-content: space-around; }

    aside .artículo3 { background: #92abef; height: 15rem; width: 70%; margin: 2rem 0.5rem 2rem 1rem ; }

    aside .artículo4 { background: #92abef; height: 15rem; width: 30%; margin: 2rem 1rem 2rem 0.5rem ; }

footer { width: 100%; background: #efa3e9; height: 5rem; }