My CSS isn't being applied to HTML for some divs

[lalita]

I'm using the Impulse theme on Shopify.My shopify store link is mekarwangi.myshopify.com and password is vaipre . These issues are both on the product page. My aim is to put some space between the div and other elements on the page. I have 2 main issues. The first is:

I added a div in my product-template.liquid file, the html is:

<div id = "replies"> Typically replies within 2-3 days! </div>

The css in the theme.css.liquid file is:

#replies{
       margin-top: 15px;
       margin-bottom: 10px;
        }

For some reason, the css isn't being applied to the div today, even though it was yesterday. This is super weird as it should be extremely simple and straightforward.

My second issue is the same, css isn't being applied to html in the same file.

html:

<div class="product-single__description rte" id = "productdescription">
                {{ product.description }}
              </div>

css:

   @media screen and (max-width: 768px) {
      #productdescription{
      text-align: center;
      }
    }

Both these methods worked yesterday but for some reason don't work today. Any insight would be highly appreciated. Thank you!

[ErSanjay]

@lalita  maybe you write the wrong CSS code or not properly  that the  else problems

I can see the only one style  added from your theme.css

so can you tell me the exact change you need on the product page?

[lalita]

It's solved now, thank you!