如何使输入字段不透明度不影响其中的文本颜色？

I have a dark/black background image and a white input field. I gave the input field an opacity of 50% and I want the text/value to be solid white(#fff). BUT when I apply the opacity it effects both the background of the input element and the text. How to I only change the background of the input field?I have a dark/black background image and a whit