.contenedor { background: #a8e6ce;  max-height: 960px; max-width: 100% ; margin: 50px 50px 0px 50px; }
header { padding: 0% text-align: left}
section { background: #a8e6ce;  text-align: right; margin-bottom: 0px}
section article {max-height: 960px; margin: 0% ; padding: 2%; text-align: center}
main { background: #a8e6ce; padding: 0%; margin: 50px;  text-align: center; min-height: 400px}
.menu { background: #000000; min-height: 15px; margin:  1%; padding: 1.5% ; text-align: center; font-family: sans-serif; color:beige}
.sumate { background: #000000; min-height: 400px ; margin: 1%; ; text-align: center; font-family: sans-serif; position: center ; color: beige; }
.mensaje-bienvenidos { background: rgba(255, 255, 255, 0.56); height: 300px ; width: 35%; text-align: center; font-family: sans-serif; margin: 100px 350px 200px 350px; border: none; font-size: 16px; }
.cuadrado { background: rgba(255, 255, 255, 0.56); height: 150px ; width: 15%; margin: 50px 350px 200px 500px }
footer { display: table  ; width: 90% ; height: 50px ; float: relative ; position: center; text-align: center; margin: -180px 50px 50px 50px ; padding: 0%}
.iniciar { background: rgba(255, 255, 255, 0.56); min-height: 15px; width: 10%;   margin:  5%; padding: 1.5% ; text-align: center; font-family: sans-serif; color: black }