html, body {
    height: 100%;
}

html {
    display: table;
    margin: auto;
}

body {
    display: table-cell;
    vertical-align: middle;
}

.who_header {
font-size: 40px;
font-weight: bold;
color: black;
background-color: #8ed3fb;
}

.who_title {
font-size: 40px;
}

.who_txt {
font-size: 40px;
background-color: lightgrey;
}