How to display the font on a transparent background and display the transparent background in the font

How to display the font on a transparent background and display the transparent background in the font

Opacity transparency can be used in the production of web pages. To improve the effect, transparent styles are essential.

Remember to make a Web page, one of which is given a 30 high, translucent black background. There is a navigation line on it, and the color of the navigation font becomes gray-black, I wanted to make it a white font. I thought it was the ul layer of the font under the background block. I wanted to use z-index to increase the height of the font, but it was useless.

At that time, I still don't know opactiy's application or code writing format. One is to use the opacity value between 0 and 1, and to display the content on a transparent background, when the background is transparent, You Need To directly use the four values in the parentheses after rgba (,). The first three values are the corresponding values of the color, the last one is the transparency value of the background.