p {
    font: 14px Arial, Helvetica, sans-serif;
    margin-top: 4px;
}
h1 {
    font-family: "Trebuchet MS";
    font-size: 24pt;
    color: #000000;
    margin-bottom: 20px;
}  
h2 {
    font-family: "Arial";
    font-size: 18pt;
    color: #000000;
    margin-top: 30px;
    margin-bottom: 20px;
}

.block {
    position: relative;
    width: 700px; 
    left: 50%;
    margin: 0 0 0 -350px;
}
.invulveld { 
    font-family: Arial, Sans-Serif;
    font-size: 15px;
    height: 30px;
    margin-bottom: 5px;
    margin-top: 20px;
    display: block;
    padding: 4px 4px 4px 4px;
    border: solid 1px #222222; 
    width: 500px;
    background-color: #efefef;
} 
.invulveld:focus { 
    font-family: Arial, Sans-Serif;
    font-size: 15px;
    margin-bottom: 5px;
    display: block;
    padding: 4px;
    border: solid 1px #000000; 
    width: 500px;
    background-color: #ffffff;
}