Change CSS

Hi thanks your plugin. It´s very good. I need help with change css,because i try change color of tab “items” for red, but sometimes works and sometimes didn´t work. So on firefox, works well in include products and show tab red. On chrome, sometimes change. I change css file e style.less but i don´t idea what is wrong. can i help?

https://ww.wp.xz.cn/plugins/woocommerce-cart-tab/