[questions/qa-css-charset] "Default" encoding for CSS?

[James-E-A]

[source] (https://www.w3.org/International/questions/qa-css-charset) [en]

Is there any official guidance on how browsers should interpret CSS documents that lack any encoding declaration?

For example, the latest version [117.0.2045.47] of Microsoft Edge yields mojibake when rendering this page: https://www.devever.net/~hl/omi

• The (X)HTML page declares its encoding to be UTF-8 in a <meta> tag
• The external CSS file's encoding is not declared in any way
• The external CSS file contains several non-ASCII byte sequences:
  • { 0xe2, 0x80, 0x93 } (can be interpreted as “–” or as “–”)
  • { 0xc2, 0xb7 } (can be interpreted as “·” or as “·”)
  • { 0xe2, 0x8f, 0xa9, 0xef, 0xb8, 0x8e } (can be interpreted as “â�©ï¸Ž” or as “⏩︎”)
    [*The latter includes U+FE0E Variation Selector 15, which is supposed to make it display in its non-Emoji form.]
  • { 0xe2, 0x8e, 0x8c } (can be interpreted as “⎌” or as “⎌”)
  • { 0xe2, 0x9d, 0x8f } (can be interpreted as “â��” or as “❏”)
  • { 0xe2, 0x96, 0xbd } (can be interpreted as “â–½” or as “▽”)

Obviously, the administrator of this website SHOULD be declaring his encoding (whether it be UTF-8 or Windows-1252). But, given that he hasn't, is Edge's behavior here at least ALLOWABLE?

[James-E-A]

yields mojibake ...

Actually, on further testing, Edge's behavior here is intermittent, and it switched to UTF-8 permanently after I loaded the CSS file's URL in its own document tab (presumably something to do with cached auto-detection?)

But my question still stands as originally posed.

[xfq]

When a style sheet is embedded in the style element or style attribute, the style sheet shares the character encoding of the document.

When a style sheet resides in a separate file, see https://www.w3.org/TR/css-syntax-3/#input-byte-stream for how browsers should interpret.

There are some tests in:

• https://www.w3.org/International/tests/repo/results/css-input-byte-stream
• https://wpt.fyi/results/css/css-syntax/charset?label=experimental&label=master&aligned