#mainForm {
    display: flex;
    justify-content: center;
}

#mainForm > form {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    justify-items: center;
    align-items: center;
    gap: 10px;
    width: 50%;
    min-width: 600px;
}

#mainForm > form > div:not(.checkbox) {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

#mainForm > form > div.checkbox {
    display: flex;
    flex-direction: row;
}

#mainForm > form > button, #mainForm > form > span {
    grid-column: 1 / span 2;
}