typography（typography 命令行）

Typography

Professional typography for user interfaces, grounded in principles from the masters.

"Typography exists to honor content." — Robert Bringhurst

Reference Files

For detailed guidance on specific topics, consult these references:

Output Formats

Type System Recommendations

## Type System

### Scale
- Base: [size, e.g., 16px]
- Ratio: [e.g., Minor Third 1.200]
- Rationale: [why this ratio]

### Hierarchy
| Level | Size | Weight | Line Height | Letter Spacing | Use |
|-------|------|--------|-------------|----------------|-----|
| Display | ... | ... | ... | ... | Hero, marketing |
| H1 | ... | ... | ... | ... | Page titles |
| H2 | ... | ... | ... | ... | Section heads |
| Body | ... | ... | ... | ... | Paragraphs |
| Small | ... | ... | ... | ... | Captions, labels |

### Fonts
- Primary: [font] — [rationale]
- Secondary: [font, if applicable]
- Mono: [font, if applicable]

### Implementation
[Ready-to-use CSS/Tailwind]

Typography Audits

## Typography Audit

### Issues
| Element | Problem | Recommendation |
|---------|---------|----------------|
| ... | ... | ... |

### Quick Wins
- [Immediate improvement 1]
- [Immediate improvement 2]

Core Principles

The Four Fundamentals (Bringhurst)

The most important typographic considerations for body text:

1. Point size — 16px minimum for body; 14px absolute floor for secondary text
2. Line spacing — 1.5-1.7 for body; 1.1-1.3 for headings
3. Line length — 45-75 characters (66 ideal); use max-w-prose (~65ch)
4. Font choice — Match typeface to content and context

Hierarchy Through Contrast

Establish hierarchy using multiple dimensions:

"Use one typeface per design. Avoid italics and bold—rely on gradations of scale instead." — Massimo Vignelli

Restraint

• 1-2 font families maximum — One serif, one sans if pairing
• 3-4 heading levels in practice — Deeper nesting usually signals structure problems
• Stick to your type scale — Resist arbitrary sizes
• Let whitespace work — Don't fill every gap

"In the new computer age, the proliferation of typefaces represents a new level of visual pollution." — Massimo Vignelli

Type Scales

Modular Scale Ratios

Practical Scale (Minor Third @ 16px)

--text-xs:   12px;  /* 0.75rem */
--text-sm:   14px;  /* 0.875rem */
--text-base: 16px;  /* 1rem */
--text-lg:   18px;  /* 1.125rem — not in pure scale */
--text-xl:   20px;  /* 1.25rem */
--text-2xl:  24px;  /* 1.5rem */
--text-3xl:  30px;  /* 1.875rem */
--text-4xl:  36px;  /* 2.25rem */
--text-5xl:  48px;  /* 3rem */

When to Deviate

• Marketing/hero: Larger jumps allowed
• Dense data interfaces: Tighter scale
• Mobile: Slightly larger base (17-18px)

Spacing Guidelines

Line Height by Context

"The eye does not read letters, but the space between them." — Adrian Frutiger

Letter Spacing

All-caps rule: Always add tracking. Keep short (1-3 words).

Paragraph Spacing

• Between paragraphs: 1em to 1.5em (equal to or slightly more than line-height)
• After headings: Reduced top margin on first paragraph
• Between sections: 2-3× paragraph spacing

Font Selection

System Font Stacks

/* Sans-serif (modern) */
font-family: ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";

/* Serif */
font-family: ui-serif, Georgia, Cambria, "Times New Roman", serif;

/* Monospace */
font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

Safe Web Font Recommendations

Pairing Principles

• Pair by contrast — Serif + sans-serif
• Match x-height — For visual harmony when mixed
• Ensure weight availability — Both need needed weights/styles

"A father should not have a favorite among his daughters." — Hermann Zapf (on his typefaces)

Modern CSS Typography

Text Wrapping

/* Balanced line lengths for headings (≤6 lines) */
h1, h2, h3, blockquote, figcaption {
  text-wrap: balance;
}

/* Prevent orphans in body text */
p, li {
  text-wrap: pretty;
}

Caveat: Don't use balance inside bordered containers—creates visual imbalance.

Fluid Typography

/* Font scales smoothly between breakpoints */
h1 {
  font-size: clamp(2rem, 1rem + 4vw, 4rem);
  line-height: clamp(1.1, 1.3 - 0.1vw, 1.3);
}

body {
  font-size: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
}

See fluid-typography.md for complete scale.

Text Truncation

/* Single line */
.truncate {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Multi-line (2 lines) */
.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

Dark Mode Typography

Weight Adjustment

Text appears heavier on dark backgrounds. Reduce weight slightly:

@media (prefers-color-scheme: dark) {
  body {
    font-weight: 350; /* Instead of 400 */
  }
  h1, h2, h3 {
    font-weight: 600; /* Instead of 700 */
  }
}

Font Smoothing

Apply antialiasing on dark backgrounds to counter perceived boldness:

.dark-bg {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

Color Contrast

• Avoid pure white (#fff) on pure black (#000)—too harsh
• Use off-white (#f5f5f5) and near-black (#1a1a1a)
• Aim for 10:1 to 15:1 contrast in dark mode

Typographic Details

Quotation Marks

Use curly quotes, not straight:

• Correct: "Hello" and 'world'
• Incorrect: "Hello" and 'world'

Dashes

Numbers

See opentype-features.md for complete reference.

Accessibility

Minimums

User Preferences

/* Use relative units so users can scale */
body {
  font-size: 1rem; /* Not 16px */
}

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}

Dyslexia Considerations

• Avoid justified text
• Prefer sans-serif with distinct letterforms (a vs α, l vs 1 vs I)
• Generous line height and paragraph spacing
• Consider offering OpenDyslexic as option

Common Mistakes

Avoid

• All-caps body text or long headings
• Centered body paragraphs
• Line length over 80 characters
• Insufficient contrast for "aesthetic" reasons
• Mixing too many font families (>2)
• Decorative fonts for UI text
• Justified text on the web
• Tiny gray text on white backgrounds
• Letter-spacing on Arabic text

Watch For

• Orphans and widows in prominent text
• Inconsistent heading hierarchy
• Missing font fallbacks
• Layout shift from web font loading
• Underlined text that isn't a link

Quick Implementation

Minimal Professional Setup

:root {
  --font-sans: Inter, ui-sans-serif, system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
}

body {
  font-family: var(--font-sans);
  font-size: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  line-height: 1.6;
  font-feature-settings: "kern" 1, "liga" 1, "calt" 1;
}

h1, h2, h3 {
  line-height: 1.2;
  text-wrap: balance;
  letter-spacing: -0.02em;
}

p {
  text-wrap: pretty;
  max-width: 65ch;
}

code {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums slashed-zero;
}

@media (prefers-color-scheme: dark) {
  body {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }
}

Tailwind Quick Start

<article class="
  prose prose-gray lg:prose-lg
  prose-headings:text-balance
  prose-p:text-pretty
  dark:prose-invert
  max-w-prose mx-auto
">
  <!-- Content -->
</article>

See tailwind-integration.md for complete patterns.