=== Base64-encoded data ===
You may use base64-encoded <code>data</code> URIs for safety and complete flexibility as shown in the example below. Using base64-encoding removes any risks and problems with illegal characters completely. Note again the presence of the comma, now after the keyword '
base64'. This is essential in a data URI, whether base64 is used or not.
If you are using any non-ASCII characters in your CSS text, unless you have already CSS backslash-hex-encoded them, which avoids the issue, your CSS should be Unicode text and you must first UTF-8-encode your CSS into a byte stream, before then base64-encoding those bytes. You ''must'' then also declare that your original CSS text was UTF-8 as in the example below.