Why isn't my live site reflecting changes from theme customizer?

Hello,

The site is bio-equine.myshopify.com

Using Shopify theme: sense

The main image is a slideshow with text overlay. I need to increase the size of the subheader “The NATURAL therapeutic advantage”.
I have created a custom css file, placed it after the base.css file in the theme.liquid file. Other customizations from it are working fine. I placed some code to target this font and make it larger and it works! but only when viewed from the theme customizer?? when viewing the front end the font stays small.

I used the following code:
p[data-live-text-setting=“section.template–18552143577395__f3e52a41-2f7d-4d6c-916a-4228c4bae998.block.template–18552143577395__f3e52a41-2f7d-4d6c-916a-4228c4bae998-1680302647e8189010-0.subheading”] {
font-size: 3.0em !important;
}

Fixed it for now by just targeting .slideshow__text instead with the following code:
.slideshow__text {
font-size: 3.0em;
}

I don’t like this solution because it targets all slideshow text on my site, but it will work for now.