style.css

.quiqqer-order-button-add-quantity-decrease,
.quiqqer-order-button-add-quantity-increase {
    border-radius: 0;
}

.quiqqer-order-button-add-quantity-decrease:hover,
.quiqqer-order-button-add-quantity-increase:hover {
    background: #eee;
    color: inherit;
}

.quiqqer-order-button-add-loader {
    font-size: 2rem !important;
}

/* product data more */
.product-data-more-tabs {
    border-bottom: 1px solid #f1f1f1;
}

li.product-data-more-tabs-tab {
    background: #fff;
    border-color: transparent;
    margin-bottom: -1px;
    outline: none;
}

li.product-data-more-tabs-tab.active {
    border: 1px solid #f1f1f1;
    border-bottom-color: #fff;
}

.product-data-more-tabs-tab a {
    color: inherit;
}

.product-data-more .product-data-more-sheets {
    border-top: none;
}