body {
    overflow: hidden;
    position: relative;
}
  
.background {
    opacity: 0.04;
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: auto;
}
  
.content {
    position: relative;  
    padding: 1rem; 
}

.titel {
    display: flex;
    justify-content: center;    
}

form{
    padding-top: 2rem;
    text-align: center;
}

#opmerking {
    color: red;
    text-align: center;
}