body{
   background-color: greenyellow;
   text-align: center; 
   font-family: Helvetica, Arial, sans-serif;
   font-size: 20px;
}   
.button {
    display: inline-block;
    text-decoration: none;
    font-size: 18px;
    width: 150px;
    margin-bottom: 1rem;
    font-weight: 700;
    line-height: 48px;
    letter-spacing: .1px;
    white-space: wrap;
    border-radius: 8px;
    cursor: pointer;
    color: #fff8f1;
    background-color: green;
    box-shadow: 0 5px 0 darkgreen;
}
.button:active {
    box-shadow: none;
    transform: translateY(5px);
}
header {
    background-color: #33cc33;
    height: 50px;
    padding: 0 20px;
    display: flex;
    align-items: center;
    width: auto;
    border-radius: 10px;
}    
nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
}
nav ul li {
    margin-right: 20px;
}  
nav ul li a {
    color: #000;
    text-decoration: none;
    font-size: 16px;
}  
nav ul li a:hover {
    text-decoration: underline;
}
#progetti, #progetti th{
    margin: auto;
    padding: 5px;
    border: 2px solid;
    border-collapse: collapse;
    background-color: #fb0;
}
#progetti td{
    background-color: #ff0;
    border: 2px solid;
    border-collapse: collapse;
    padding: 3px;
}