.complex-calculator-container {
    max-width: 750px;
    margin: 0 auto;
}

.complex-calculator .input-group-text {
    background-color: #f1f5f9;
    color: #475569;
    min-width: 35px;
    justify-content: center;
}

#res-complex-val {
    letter-spacing: 1px;
}