app/static/stripe.css

/*
    CSS stylesheet of the Stripe payment form.
*/

.StripeElement {
    background-color: white;
    height: 36px;
    padding: 10px 12px;
    border-radius: 4px;
    border: 1px solid transparent;
    box-shadow: 0 1px 3px 0 #e6ebf1;
    -webkit-transition: box-shadow 150ms ease;
    transition: box-shadow 150ms ease;
}

.StripeElement--focus {
    box-shadow: 0 1px 3px 0 #cfd7df;
}

.StripeElement--invalid {
    border-color: #fa755a;
}

.StripeElement--webkit-autofill {
    background-color: #fefde5 !important;
}