How can I create rounded corners on sections in the Cornerstone theme?

Topic summary

Goal: add rounded corners to section/cards in the Cornerstone (Barista style) theme, specifically the three “Latest deals” boxes.

Key solutions proposed:

  • Target the specific promo tiles: use CSS on .promotion-grid-item or .promotion-grid-item__inner (e.g., border-radius: 10px). For broader coverage, try [class*=‘grid-item’] but test carefully. Note: existing borders/containers may require adjustments. Recommended to add CSS via the theme’s custom CSS setting per Shopify docs before editing files.
  • Apply a broader rule to round items within sections: edit base.css/style.css/theme.css and append .section-inner * { border-radius: 10px; }. This sets the CSS border-radius (rounds element corners) on all elements inside .section-inner. A screenshot was provided showing the result.

Outcome:

  • The broader .section-inner * approach worked for the requester, who confirmed success. Discussion resolved.

Notes:

  • Broad selectors may affect many nested elements; verify visual results across the site. If only certain blocks need rounding, prefer targeting specific classes to avoid unintended styling.
Summarized with AI on January 9. AI used: gpt-5.

I am using cornerstone shopify theme I need to add radius to corners of the boxes, sections or cards whatever it is called I actually want every individual section of theme to be rounded for example the 3 boxes under the title “latest deals” on this link https://themes.shopify.com/themes/cornerstone/styles/barista/preview I need there corners to be rounded.

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EVERY , ALL, etc is waay beyond the scope of the forums that’s design work hire someone.

For just that section use class .promotion-grid-item, or the inner .promotion-grid-item__inner, and css like the following though you’ll have to do adjustments because of the existing border of that element as a container.

Crudely

.promotion-grid-item { border-radius: 10px; }

To try and target more “grid-items” you can try to use this selector [class*=‘grid-item’], test carefully.

Test and use a custom-css setting before changing files directly

https://help.shopify.com/en/manual/online-store/themes/theme-structure/extend/add-css

If you need this designed then contact me by my email for services.
Contact info in forum signature.
ALWAYS please provide context, examples: store url, theme name, post url(s) , or any further detail in ALL correspondence.

Good Luck.

Hi @AbdulLatif99

Check this one.

From your Shopify admin dashboard, click on “Online Store” and then “Themes”.

Find the theme that you want to edit and click on “Actions” and then “Edit code”.

In the “Assets” folder, click on “base.css, style.css or theme.css” file, depending on which file your theme uses to store its CSS styles. At the bottom of the file, add the following CSS code:

.section-inner * {
    border-radius: 10px;
}

And Save.

Result:

Please don’t forget to Like and Mark Solution to the post that helped you. Thanks!

Worked Perfectly Thanks

1 Like