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

body {
    background-color: #3C505E   
}

h1 {
    color:#3C505E   
}

h2 {
    color: #3C505E;
}

.uno {
    height: 200px;
    background-color: #92BEDE;
    border: 2px solid #3C505E;
    
}
.dos {
    height: 200px;
    background-color:#DD9291;
    border: 2px solid #3C505E
}

.tres {
    height: 200px;
    background-color: #92BEDE;
    border: 2px solid #3C505E
}

.caja1 {
    height: 700px;
    background-color: #DEDE92;
    border: 2px solid #3C505E;    
}

#cabecera {
    margin: 20px 0px 20px 0px;
    border: #92BEDE dashed 2px;
    padding: 20px;
}