h1,
h2,
h3 {
    background-color: rgb(20, 100, 200);
}

h1:hover,
h2:hover,
h3:hover {
    background-color: rgb(139, 190, 232)
}

header {
    margin-left: 40px;
    margin-right: 40px;
}

table img {
    height: 150px;
}

.centerd {
    padding: 10px;
    text-align: center;
}

header img {
    height: 100px;
}

figure {
    text-align: right;
}

figure figcaption {
    text-align: center;
}

table td,
table th {
    border-style: double;
    border-width: 4px;
}

table {
    margin-left: auto;
    margin-right: auto;
    border-collapse: collapse;
}

ul {
    list-style: square;
}

footer p {
    font-size: small;
    margin-bottom: 20px;
}

iframe {
    width: 100%;
    border-radius: 15px;
}

address {
    font-weight: bold;
    margin-top: 20px;
    font-variant: small-caps;
}

fieldset {
    border-color: rgb(255, 210, 0);
    border-width: 2px;
    padding: 20px;
    display: flex;
    flex-direction: column;
}

legend {
    color: rgb(20, 100, 200);
}

.knop {
    margin-left: 20%;
    margin-right: 20%;
}

#send {
    height: 45px;
    padding: 5px;
}

#kennis {
    width: 100%;
}

mark {
    color: rgb(255, 210, 0);
}