A small screen isn't just a scaled-down version
Squeezing three desktop columns onto a phone doesn't create a readable experience. Cards should be stacked, text lines should be easy to read, and action buttons should be spaced apart. Fixed headers shouldn't obscure content. It is normal for headings to wrap to two lines; it is not normal for words to be cut off or for horizontal scrolling to be required.
Complete the actual task
Open the menu on the phone, review a package, type into a form, and go back to the previous step. Are the error message and "continue" button visible when the keyboard is open? Does the page end up unexpectedly low down after a selection? Simply looking at a screenshot won't reveal these behaviors. Waiting feedback for slow connection speeds should also be checked.
Don't forget text direction
In an Arabic interface, drop-down menus and sliding panels shouldn't extend off-screen. Arrow icons, spacing, and alignment should adapt to the text direction. Numbers, email addresses, and currency amounts, however, should retain their readability. Testing with real content in different languages is more reliable than testing with short sample text.
Your quick checklist
- Complete the form on a phone.
- Check for horizontal overflow.
- Test the Arabic menu separately.