RGBA has somewhat limited support on mobile browsers: https://caniuse.com/#search=rgba
There are some techniques for providing fallbacks to browsers that cannot deal with the rgba values. I noticed in your site header, you have css background-color
and background
properties both using the same value.
One approach is to use two different background
rules with the first one set the value to a rgb
value that non-supporting browsers will use as a fallback:
background: rgb(0, 84, 166); /* fallback color */
background: rgba(0, 84, 166, 0.5);
There are other approaches that use filters to try and maintain the transparency on non-supporting browsers. Here is a good article that goes into more depth: https://css-tricks.com/rgba-browser-support/