Readability: cirno.svg has pure white with no background

[tutacat]

For readability, it would be useful to include a darker background or an outline of some kind, to make the white text readable on a white screen.

Some ways this could be achieved:

• add an outline (font stroke) to the text, such as black/grey
• add a flat background, maybe transparent, behind the text
• use a "shadow" style background behind the text
• remove color attributes from the white portion of text (use the inherited color)
• use CSS to detect prefers-color-scheme and default to black color
• change from white to some other color