body {
    background-color: #b4b4b4;
}

.container {
    max-width: 500px;
    margin: 50px auto;
    background-color: #fff;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.form-container {
    margin: auto;
}

.input-group {
    margin: 10px;
    display: flex;
    justify-content: space-between;
}

.input-group > div {
    margin: 0;
    padding: 0;
}

select#customer{
    min-width: 100px;
}

input#quantity {
    width: 2em;
}

input#price {
    width: 5em;
}

.button-container {
    margin-top: 20px;
    display: flex;
    justify-content: center;
}