This code constructs CSS rules dynamically to set the font-family...
This code constructs CSS rules dynamically to set the font-family for various elements (body
, input
, textarea
, button
) based on the user's system fonts and local settings (including language or locale). The main aspects of what this code does are:
-
Default Font-Family Setup: It specifies a default font stack using
-apple-system
,BlinkMacSystemFont
,Roboto
,Helvetica Neue
, and others, as a fallback mechanism suitable for various operating systems (macOS, Android, etc.). -
Language-Specific Fonts: The code creates additional CSS rules that apply specific fonts for certain languages or locales using the CSS
:lang()
selector. For example:- Arabic (
ar
) uses'Segoe UI Web (Arabic)'
. - Japanese (
ja
) uses fonts like'Yu Gothic UI'
,'Meiryo UI'
, or'MS Pgothic'
. - Other locales have their respective font-family settings.
- Arabic (
-
Exclusion Rules: Font styles are excluded for certain elements like icons (
.ms-Icon
) or items with specificdata-icon-name
attributes to avoid conflicts with icon fonts. -
Purpose and Output:
- The code builds a string of CSS rules that effectively style the page's text based on the user's language and font preferences.
- It dynamically adds these rules to the DOM upon execution, applying the styles immediately.
-
Helper Functions: It uses utility functions like
s()
to detect the operating system or environment (e.g.,isWindows
) and tailor the generated CSS accordingly. -
SVG and Image Assets: Toward the end, there are references to various SVG symbols, gradients, and image files. These likely support visual elements of the application or website but are unrelated to the primary font styling logic.
In summary, this block of code customizes font rendering to suit different languages and operating systems, ensuring a consistent and optimal experience for users worldwide.