What Salla's CSS field requires
According to Salla's help centre, custom CSS is added under Store Design, then Theme Customisation, and the feature requires the Pro or Special plan and a custom domain. We check this on your store before quoting, so you never pay for a change that can't be applied.
What CSS can't fix
CSS changes appearance: colours, sizes, spacing, hiding and visual order. It can't change text inside the theme, pricing or shipping logic, or SEO titles. If your request is of that kind we tell you, and suggest the right setting, app or custom theme instead.
How changes survive theme updates
We write short selectors tied to the class names the theme uses, comment every change, keep a copy of the code, and re-test on mobile and desktop. Our blog guide to editing a Salla theme with CSS explains it with examples.