Styles

A style is a flat object with CSS-like field names:

{ "fontSize": 12, "color": "#333333", "lineHeight": 1.5, "borderBottom": "1pt solid #D0D7DE" }

Values follow what Word can express. If a format can’t express a field, it is ignored with a warning — not an error. Unknown fields are errors.

Field groups

All fields sit at one level in JSON. The groups only help you find them:

Group	Examples	Reference
Text	fontFamily fontSize color bold underline	Text style
Paragraph	align lineHeight spaceBefore textIndent	Paragraph style
Borders, background, box	border background padding width	Borders, background and box
List	listStyleType listMarkerFormat listIndent	List style
Image position	position float wrap x y	Image style
Table	cellPadding repeatHeader tableLayout	Table style

How to write lengths, colors, borders and so on: Values.

Where styles go

Four places, all written the same way:

1. An element’s style: that element only.
2. An element’s parts: one part of that element.
3. Top-level styles:
   • A key that is a component name is a component style and applies to every element of that component: "Text", "Heading.1", "Table.header".
   • Any other key is a named style that elements reference by name: "style": "muted".
4. Style sets: a whole look, which can live in a separate file and be shared. See Style sets.

"styles": {
  "Text": { "textIndent": "2em" },
  "Heading.1": { "align": "center" },
  "Table.header": { "background": "#1A73E8", "color": "#FFFFFF" },
  "muted": { "color": "#666666", "fontSize": 10 }
}

Component style keys:

Key	Applies to
Heading Text Code List Table Image Slide Section Document	All elements of that component
InlineCode	Inline code in runs
Heading.1 … Heading.6	One heading level
List.level1 … List.level9, List.marker, List.item	A list level, the marker, item text
Table.header, Table.evenRow, …	Table parts; see Tables
Image.caption, Slide.title, Slide.body	Other parts
CustomName	Root element of an expanded custom component
CustomName:templateId	One element inside a custom component, optionally followed by .part

Unknown component names or parts in keys are errors.

Inheritance

As in CSS, some fields pass from parent to child and some don’t.

• Inherited: text fields, most paragraph fields and list fields. Specifically fontFamily fontSize color bold italic underline underlineColor strike caps letterSpacing highlight emphasisMark scale kerning lang hidden align lineHeight textIndent hangingIndent widowControl contextualSpacing autoSpace kinsoku direction, and every list* field except listStart.
• Not inherited: verticalAlign spaceBefore spaceAfter marginLeft marginRight keepWithNext keepTogether pageBreakBefore wrap outlineLevel, every border, background, box, image-position and table field, and listStart.

So fontSize on the Document changes the whole document, while border on the Document only frames the document itself.

Combination order

An element’s final style is built in this order; later steps win:

1. Inherited fields from the parent. The root’s “parent” is the built-in global defaults plus the style set’s global.
2. Built-in component defaults: Heading, then Heading.1.
3. The style set’s component styles: Heading, then Heading.1.
4. Component styles from the top-level styles: again Heading, then Heading.1.
5. The style written in a custom component’s template.
6. Component styles that name the custom component: Callout, Callout:head.
7. The element’s own style. Later array entries win.
8. Text styles on runs (for that bit of text only).

Notes:

• Step 1 is the weakest. Component styles always beat inherited values, as in CSS.
• Step 4 comes after step 3: the style set is the base, the document’s own styles win.
• Part styles follow the same order: built-in → style set → top-level styles → template parts → Name:elementId.part → the element’s own parts. Part styles are applied on top of the element’s style.
• fontFamily merges per script. "fontFamily": "Times New Roman" followed by { "eastAsia": "SimHei" } gives Times for Latin and SimHei for CJK.

Built-in defaults

This is what you get when you write nothing:

Key	Default
global	fontSize 10.5, lineHeight 1.5
Heading	bold, keepWithNext, 12 before, 6 after, lineHeight 1.25
Heading.1 … Heading.6	sizes 20 / 16 / 14 / 12 / 11 / 11; level 1 has 18 before
Text	6 after
Code	monospace, 9pt, lineHeight 1.4, background #F6F8FA, padding 8, 8 after, keepTogether
InlineCode	monospace, background #F0F1F3
List	6 after, listIndent 2em, listHanging 2em
Table	border 0.5pt solid #999999, cellPadding 4, repeatHeader, 8 after
Table.header	bold, background #F3F3F3
Image	6 after
Image.caption	9pt, #666666
Slide.title	20pt, bold

Numbers are in pt. Monospace is Menlo, Consolas, DejaVu Sans Mono. Links default to #0563C1, underlined.

Example

styles-basic.json

{
  "version": "0.1",
  "meta": { "title": "Style example", "lang": "en" },
  "styles": {
    "Document": { "fontSize": 11, "lineHeight": 1.6 },
    "Heading.1": { "align": "center", "color": "#1F2328" },
    "Text": { "textIndent": "2em", "align": "justify" },
    "note": { "background": "#FFF8C5", "borderLeft": "3pt solid #D4A72C", "padding": 8, "textIndent": 0 }
  },
  "root": "doc",
  "elements": {
    "doc": { "type": "Document", "children": ["title", "p1", "tip"] },
    "title": { "type": "Heading", "props": { "level": 1, "text": "Style example" } },
    "p1": { "type": "Text", "props": { "text": "Paragraphs are justified with a first-line indent. Font size and line height are set on the Document and inherited everywhere." } },
    "tip": { "type": "Text", "props": { "text": "This callout uses the named style note: a thick left border on pale yellow." }, "style": "note" }
  }
}