*{margin:0; padding:0; box-sizing: border-box}
.contenedor {max-width: 60rem; margin:auto}
header {width: 100%; height: 4rem; background-color:greenyellow;margin-top: 1rem}
h1 {text-align: center; font-family: Arial, sans-serif; font-size: 2rem; padding: 1%}
main {width: 100%; height: 60rem; border: 4px solid black; display: flex; flex-wrap: wrap; justify-content: space-around; margin-top: 0.3rem}
section {width: 60%; height: 99%; background-color:cyan; display: flex; flex-wrap: wrap; justify-content: space-around; margin-top: 0.3rem }
section article {width: 98%; height: 31%; margin: 1%; background-color: yellow ;padding-bottom: 1rem}
aside {width: 39%; height: 55%; background-color:gray; flex-wrap: wrap; justify-content: space-between; margin-top: 0.3rem }
footer {width: 100%; height: 4rem; background-color:darkgreen; margin-top: 0.3rem; margin-bottom: 1rem }