docs: Enhance font documentation and add new font families

- Added a new section for "Fonts" in the documentation, including an overview and quick start guide.
- Introduced detailed documentation for 9 font families, including usage examples and visual previews.
- Implemented font utility functions for size and weight adjustments, enhancing typography management.
- Generated high-resolution images for each font family and utility demonstration.
- Updated the main documentation index to include links to the new font resources.

Author: wonjun-lab

docs/conf.py

@@ -68,6 +68,7 @@
         {"title": "Installation", "url": "installation/index"},
         {"title": "Usage Guide", "url": "usage_guide/index"},
         {"title": "Color System", "url": "color_system/index"},
+        {"title": "Fonts", "url": "fonts/index"},
         {"title": "Examples Gallery", "url": "examples_gallery/index"},
         {"title": "API Reference", "url": "api/index"},
     ]

docs/fonts/families.md

@@ -0,0 +1,270 @@
+# Font Families
+
+dartwork-mpl bundles 9 professional font families with a total of 130 font
+variants. Each family is optimized for different use cases in data visualization.
+
+## Roboto (Default)
+
+:::{figure} images/font_roboto.png
+:alt: Roboto font family preview
+:width: 100%
+:::
+
+Google's flagship sans-serif typeface and the **default font in dartwork-mpl**.
+Roboto features friendly, open curves while maintaining a mechanical skeleton,
+making it highly legible at all sizes.
+
+**Variants:** 15 (Thin, Light, Regular, Medium, Bold, Black + Italics)
+
+**Best For:**
+- General-purpose body text
+- Axis labels and tick marks
+- Legends and annotations
+
+**Usage:**
+```python
+import matplotlib.pyplot as plt
+plt.rcParams['font.family'] = 'Roboto'
+plt.rcParams['font.weight'] = 300  # Light weight (dartwork default)
+```
+
+---
+
+## Inter
+
+:::{figure} images/font_inter.png
+:alt: Inter font family preview
+:width: 100%
+:::
+
+A modern sans-serif typeface designed specifically for computer screens. Inter
+features a tall x-height for improved readability at small sizes and includes
+many OpenType features.
+
+**Variants:** 20 (Thin through Black, with Italics)
+
+**Best For:**
+- UI-style visualizations
+- Presentations and slides
+- Screen-first publications
+
+**Usage:**
+```python
+plt.rcParams['font.family'] = 'Inter'
+```
+
+---
+
+## InterDisplay
+
+:::{figure} images/font_interdisplay.png
+:alt: InterDisplay font family preview
+:width: 100%
+:::
+
+The display variant of Inter, optimized for larger sizes. Features tighter
+letter-spacing and refined details that shine at headline sizes.
+
+**Variants:** 20 (Thin through Black, with Italics)
+
+**Best For:**
+- Figure titles
+- Section headings
+- Large callout text
+
+**Usage:**
+```python
+ax.set_title("Main Title", fontfamily='Inter Display', fontsize=24)
+```
+
+---
+
+## Noto Sans
+
+:::{figure} images/font_notosans.png
+:alt: Noto Sans font family preview
+:width: 100%
+:::
+
+Google's Noto Sans provides harmonious typography across hundreds of languages.
+The name "Noto" comes from "No Tofu"—the goal of eliminating the blank boxes
+(tofu) that appear when a font lacks a glyph.
+
+**Variants:** 15 (ExtraLight through Black, with Italics)
+
+**Best For:**
+- Multi-language documents
+- International publications
+- Unicode-heavy content
+
+**Usage:**
+```python
+plt.rcParams['font.family'] = 'Noto Sans'
+```
+
+---
+
+## Noto Sans Condensed
+
+:::{figure} images/font_notosans_condensed.png
+:alt: Noto Sans Condensed font family preview
+:width: 100%
+:::
+
+The condensed variant of Noto Sans, providing the same excellent character
+coverage in a narrower form factor.
+
+**Variants:** 20 (Thin through Black, with Italics)
+
+**Best For:**
+- Tables with many columns
+- Dense data visualizations
+- Space-constrained layouts
+
+**Usage:**
+```python
+plt.rcParams['font.family'] = 'Noto Sans Condensed'
+```
+
+---
+
+## Noto Sans SemiCondensed
+
+:::{figure} images/font_notosans_semicondensed.png
+:alt: Noto Sans SemiCondensed font family preview
+:width: 100%
+:::
+
+A middle ground between regular Noto Sans and the fully condensed variant.
+Offers good space efficiency while maintaining excellent readability.
+
+**Variants:** 20 (Thin through Black, with Italics)
+
+**Best For:**
+- Legends with many entries
+- Compact labels
+- Moderate space savings
+
+**Usage:**
+```python
+plt.rcParams['font.family'] = 'Noto Sans SemiCondensed'
+```
+
+---
+
+## Noto Sans ExtraCondensed
+
+:::{figure} images/font_notosans_extracondensed.png
+:alt: Noto Sans ExtraCondensed font family preview
+:width: 100%
+:::
+
+The most condensed variant in the Noto Sans family. Use when space is at an
+absolute premium.
+
+**Variants:** 20 (Thin through Black, with Italics)
+
+**Best For:**
+- Very tight axis labels
+- Narrow figure margins
+- Maximum information density
+
+**Usage:**
+```python
+plt.rcParams['font.family'] = 'Noto Sans ExtraCondensed'
+```
+
+---
+
+## Noto Sans Math
+
+:::{figure} images/font_notosansmath.png
+:alt: Noto Sans Math font preview
+:width: 100%
+:::
+
+A dedicated font for mathematical typesetting. Noto Sans Math provides
+comprehensive coverage of mathematical symbols, operators, and special
+characters used in scientific notation.
+
+**Variants:** 1 (Regular only)
+
+**Best For:**
+- Scientific equations
+- Mathematical notation
+- Greek letters and symbols
+
+**Usage in dartwork-mpl:**
+
+Noto Sans Math is automatically configured for mathtext rendering:
+
+```python
+# These settings are applied by dartwork-mpl styles
+plt.rcParams['mathtext.fontset'] = 'custom'
+plt.rcParams['mathtext.rm'] = 'Noto Sans Math'
+plt.rcParams['mathtext.it'] = 'Noto Sans Math:italic'
+plt.rcParams['mathtext.bf'] = 'Noto Sans Math:bold'
+```
+
+**Example:**
+```python
+ax.set_xlabel(r'$\alpha = \frac{\Delta x}{\Delta t}$')
+ax.set_ylabel(r'$\sum_{i=1}^{n} x_i^2$')
+```
+
+---
+
+## Paperlogy
+
+:::{figure} images/font_paperlogy.png
+:alt: Paperlogy font family preview
+:width: 100%
+:::
+
+A clean, professional typeface designed specifically for documents and papers.
+Paperlogy offers excellent readability in dense text environments typical of
+academic and business publications.
+
+**Variants:** 9 (Light through Black)
+
+**Best For:**
+- Academic papers
+- Technical reports
+- Professional documents
+
+**Usage:**
+```python
+plt.rcParams['font.family'] = 'Paperlogy'
+```
+
+---
+
+## Font Weight Reference
+
+All font families (except Noto Sans Math) include multiple weights:
+
+| Weight Name | Numeric Value | Description |
+|-------------|---------------|-------------|
+| Thin | 100 | Extremely light |
+| ExtraLight | 200 | Very light |
+| Light | 300 | Light (dartwork default) |
+| Regular | 400 | Normal |
+| Medium | 500 | Slightly bold |
+| SemiBold | 600 | Semi-bold |
+| Bold | 700 | Bold |
+| ExtraBold | 800 | Extra bold |
+| Black | 900 | Maximum weight |
+
+:::{figure} images/font_weights.png
+:alt: Font weight comparison
+:width: 100%
+:::
+
+**Using Weights:**
+```python
+# Direct weight specification
+ax.set_title("Title", fontweight=700)
+
+# Or use the fw() helper for relative weights
+ax.set_title("Title", fontweight=dm.fw(2))  # base + 200
+```