*, body { box-sizing: border-box; } body { width: 96%; margin: auto; margin-top: 5%; text-align: center; } fieldset { width: -moz-fit-content; width: fit-content; margin: auto; padding: 5vw; height: 6vw; display: flex; flex-direction: column; justify-content:center; } #formContent { width: 25%; background-color: lightslategray; } ::placeholder { text-align: center; }