The concept of line length in UI/UX design refers to the number of characters per line of text. Line length can significantly impact readability and user experience, as lines that are too long or too short can make text harder to read and decrease user engagement.
To mitigate the issue of line length in web design, CSS can be used to control the width of text containers and the font size. Setting a maximum width on text containers and using relative units like `em` or `rem` for font sizes ensures that text remains readable across different devices and screen sizes. Optimal line length typically falls between 45-75 characters per line.