Multiply section box shadow without affecting child elements

I have a box-shadow applied to this sticky top page section. I want the box shadow to have a "multiply" blend mode over sections that scroll up behind it. When I add mix-blend-mode: multiply; to the individual page header injection it also multiplies the text block within the section, rendering it unreadable. Does anyone know a way to prevent the text block from also multiplying?

without mix-blend-mode: multiply  added to section box-shadow

with mix-blend-mode: multiply added to section box-shadow

52 minutes ago, THDesign said:

with mix-blend-mode: multiply added to section box-shadow

I guess this is applying to everything not just the box shadow, but it's just a guess because I can't see your website or code, could you share both please?

https://sepia-gopher-rh26.squarespace.com/artifacts-history/1890-1915-taggart-cast-inlay-machine

/*NAV SECTION DROP SHADOW*/
[data-section-id="66747049f3abb2025cbd195e"] {
 box-shadow: 0px 5px 12px rgba(100, 100, 100, 0.7);
  mix-blend-mode: multiply;
  }

You're right that it's affecting everything in the section. I'd like JUST the box shadow to multiply, not the text elements as well. 

This is the closest I can find on the subject, but I'm not sure how to translate it to my situation. 

https://stackoverflow.com/questions/5080365/css-to-prevent-child-element-from-inheriting-parent-styles

7 hours ago, THDesign said:

This is the closest I can find on the subject, but I'm not sure how to translate it to my situation. 

Not sure this is helpful.

The easiest way to fix this would be to use a different rgba value, try rgba(0, 0, 0, 0.7)

Or you could use a pseudo element so you can use the blend mode on just that element, something like this:

/*NAV SECTION DROP SHADOW*/
section[data-section-id="66747049f3abb2025cbd195e"]:before {
  content:'';
  width:100%;
  height:100%;
  position:absolute;
  box-shadow: 0px 5px 12px rgba(100, 100, 100, 0.7);
  mix-blend-mode: multiply;
}

Let me know how you get on!

Sorry, that doesn't seem to work. It added a clear bar under the navigation section. The clear bar does have a box-shadow but it's blend mode appears normal for some reason. 

Thank you so much - that did the trick! Very clever solution 😀