Unicode, Color, Accessibility, and Non-TUI Fallbacks

Use this skill when terminal output must be visually correct, readable, inclusive, and robust across fonts, locales, themes, and assistive technologies.

Text correctness rules

• Display width is not byte length, code point count, or user-perceived character count.
• Cursor movement and deletion should operate on grapheme clusters.
• Layout should measure printable text after stripping ANSI control sequences.
• Double-width characters, combining marks, emoji sequences, variation selectors, and zero-width joiners must be tested.
• Treat ambiguous East Asian width as narrow by default unless the target environment explicitly differs.

Visual design rules

• Use semantic roles: error, warning, success, info, muted, selected, focused, disabled.
• Do not encode meaning by color alone; pair color with text, shape, icon, or position.
• Provide ASCII fallback for box drawing, braille charts, block elements, emoji, and private-use icons.
• Avoid assuming Nerd Fonts or patched fonts.
• Support light and dark backgrounds, 16-color, 256-color, truecolor, and no-color modes.