*{
    box-sizing: border-box;
}
body{
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background-color: #f4f4f4;
}
header{
    background-color: #c0c0c0;
    color: #ffff;
    text-align: center;
}
nav a{
    color: blue;
    text-decoration: none;
    padding: 4px;
}
.blobo{
    background-color: #cccc;
    color: black;
    border: 1px dotted #a3a3;
    border-radius: 0px;
    padding: 10px;
    margin-bottom: 10px;
    border-top: 2px solid #d8d;
    
}