How can I adjust the font size in a custom product field?

Store Design

Topic summary

A store owner added a custom text field (for letter color) on a product in the Dawn theme, but the input box and font appear too small. They are not comfortable with coding and requested help.

Several replies asked for the store URL/password to inspect. The owner provided a product link.

A concrete fix was provided: add CSS in section-main-product.css to style the custom input. Selector: .line-item-property__field input with width: 65%, height: 50px, and font-size: 30px. Steps given: Online Store > Edit theme code > find section-main-product.css > paste the CSS.

The owner then reported that after adding it, the code showed up as visible text on the product page and asked where it should be placed. They shared their current input HTML tag for the custom property.

Current status: The solution is identified (add CSS to the theme stylesheet), but implementation guidance is still needed to ensure the CSS is placed in the correct file rather than pasted into product content. No final resolution yet.

Summarized with AI on February 19. AI used: gpt-5.
1

Hello,

I added a custom product field to my clients Dawn themed storm to collect letter color on shirts. The box and font are really small and I can’t seem to fix it. Not a skilled coder and I need help.

1 Like
2

@Jivoryco

Please share your store URL & store front password!

Thanks!

3

Welcome to shopify community.

Please share your store URL and if your store is password protected then please provide password too.

Thank you.

4

@Jivoryco

Could you provide me store URL? I should be able to answer your question.

Yours faithfully!

5

Hello. Thanks! https://ctwheat.myshopify.com/products/unisex-pray-grow-and-win-together-short-sleeve-t-shirt

6

@Jivoryco

add this code to your section-main-product.css file.

Navigate to online store >> Click edit theme code.

Now find section-main-product.css and paste the following code:

.line-item-property__field input{

    width: 65%;
    height: 50px;
    font-size: 30px;
}
7

Thanks much! Just one more quick question… when I added it, it just showed up as writing on the product page. Should I be posting this between something? Below is my current input tag. Again, I am not a coder. Thanks for your grace.