Go back to Store Manager and publish your Order Settings.
Customize mobile checkout
You can edit the default or current mobile checkout style sheet for more control over the look of your checkout pages. Editing the style sheet requires advanced knowledge of CSS.
There's no way to preview your custom CSS. After you upload the CSS file and publish order settings, it's a good idea to review and test your mobile checkout to make sure it works as you intended.
In the Visual Customization section, click Download default CSS file (if you haven't already customized it) or Download current CSS file (if you've already customized it).
Edit the CSS file as needed.
Click the Choose File button to locate the CSS file that you edited.
Click the Upload button.
Click the Preview button of you wish to preview your changes. You'll see a preview of your mobile checkout as it appears on a mobile device. Note: You can switch between desktop and mobile previews by clicking the icons on top.
Go back to Store Manager and publish your Order Settings.