.woocommerce span.onsale {
    background: white;
    color: black;
    padding: 6px 10px;
    font-size: 14px;
    font-weight: 700;
    border-radius: 20px;
    position: absolute;
    top: 10px;
    left: 10px;
    z-index: 10;
    box-shadow: 0 3px 8px rgba(0,0,0,0.15);
}