Dawn theme: shopify header dropdown navigation hidden behind page

For some reason - potential edits to code - the dropdown navigation on the header is now not showing on the homepage, but will show in products page but it is hidden behind the page banner. How can I rectify this. Screenshot and URL provided:

https://managingyourinformation.com/

hey mate, that is working fine for me

It sounds like there may be a z-index issue with your header and page banner. You can try adjusting the z-index value for your header in your theme’s CSS to bring it to the front and make it visible.

Here’s an example of what the code may look like in your theme’s CSS file:

.site-header {
  position: relative;
  z-index: 9999;
}

Hi, I’m using the “Origin” theme. I’ve pasted the code in the base.css file at the bottom but it doesn’t do anything. Can you help?