body {
    display: flex;
    align-items: center;
    flex-direction: column;
}

body * {
    margin: 10px;
}

#output {
    display: flex;
    align-items: center;
    flex-direction: column;
}

#options {
    display: flex;
    align-items: end;
    flex-direction: column;
    border: 1px solid black;
    padding-top: 10px;
    padding-bottom: 10px;
}

#options * {
    margin-top: 2px;
    margin-bottom: 2px;
}

#options input {
    width: 100px;
}
#options select {
    width: 100px;
}