o3-foundation

o3-foundation
- CSS Tokens
- JS Tokens
- Typography
  - Headings
  - Body/Paragraphs
  - Links
  - List
  - Wrapper
  - Custom Properties
- Normalisation
- Stacking with z-index
- Focus rings
- Fonts
- Icons
- Colours
- Spacing
- Grid
- Helper classes
- Migration
- Contact
- Licence

CSS Tokens

o3-foundation provides CSS Custom Properties for design tokens representing colours, typographic scale, spacing, iconography, grid and typography components such as headings, body, link and etc.

o3-foundation supports brands: core, internal, professional, sustainable-views and whitelabel.

Import your chosen brand to begin using tokens in your CSS/SCSS:

@import '@financial-times/o3-foundation/css/core.css';

body {
    background-color: var(--o3-color-use-case-page-background);
    font-size: var(--o3-font-size-1);
    line-height: var(--o3-font-lineheight-0);
}

To add support for another brand, import its tokens too:

+@import '@financial-times/o3-foundation/css/core.css';
+@import '@financial-times/o3-foundation/css/internal.css';

.example-custom-link {
 color: var(--o3-color-link);
 font-size: var(--o3-font-size-3);
 line-height: var(--o3-lineheight-3);
}

Then apply the brand data selector data-o3-brand="[BRAND]" on a container element within your HTML.

<body data-o3-brand="core">
    <a href="#" class="example-custom-link">Example</a>
</body>

JS Tokens

Foundational tokens are also available as JavaScript. There are two formats:

An ESM default export with kebab case token naming.
An ESM named export for each token with camel case token naming.

Each format provides two token files:

Icon tokens.
All other branded tokens.

Default export

esm/tokens/[brand].js
esm/tokens/icons.js

Pro: Same token naming convention as with CSS Custom Properties, for discoverability and refactoring. Con: Unused tokens cannot be removed through tree-shaking, and therefore may increase your final bundle size.

import tokens from '@financial-times/o3-foundation/esm/tokens/[brand].js';

const example = `The hex for FT Pink is ${tokens['o3-color-palette-ft-pink']}`;

Named export

esm/tokens/[brand]-named.js
esm/tokens/icons-named.js

Pro: Supports tree-shaking for minimal bundle sizes. Con: Uses snake case token names, making it impossible to search for a token across JS and CSS.

import {o3_color_palette_ft_pink} from '@financial-times/o3-foundation/esm/tokens/[brand]-named.js';

const example = `The hex for FT Pink is ${o3_color_palette_ft_pink}`;

Typography

List

o3-foundation provides styling for both ordered and unordered lists:

HTML

<ul class="o3-typography-ul">
    <li>Item 1</li>
    <li>Item 2</li>
    <li>Item 3</li>
</ul>

<ol class="o3-typography-ol">
    <li>Item 1</li>
    <li>Item 2</li>
    <li>Item 3</li>
</ol>

JSX

import { List } from '@financial-times/o3-foundation/cjs'; // or esm;

<UnorderedList>
 <li>Item 1</li>
 <li>Item 2</li>
 <li>Item 3</li>
</UnorderedList>

<OrderedList>
 <li>Item 1</li>
 <li>Item 2</li>
 <li>Item 3</li>
</OrderedList>

Wrapper

The wrapper can be used to style blocks of body without needing to apply the class to each element. This can be useful when large bodies of many components need styling:

HTML

<div class="o3-typography-wrapper"></div>

import {Wrapper} from '@financial-times/o3-foundation/cjs'; // or esm

<Wrapper>
    <h1>This heading gets styled.</h1>
    <p>And so does this paragraphy of text.</p>
    <h2>This gets styled also</h2>
</Wrapper>;

Highlight (Bold)

Use typography use cases to style body content with bolder styles:

<p class="o3-type-body-base">
    This is <strong class="o3-type-body">really</strong> important.
</p>

Custom Properties

Max Line Width

o3-foundation includes a CSS Custom Property --o3-typography-max-line-width to limit typography line length for readability. E.g.

.my-selector {
    max-width: var(--o3-typography-max-line-width);
}

You may want to slightly decrease or increase this limit inline with our design guidelines. To do so we recommend using the ch relative unit.

E.g.

.my-selector {
    max-width: 70ch;
}

Normalisation

o3-foundation provides a set of CSS Custom Properties for normalising the default browser styles and also applies a set of defaults to elements. This is to ensure a consistent starting point for all projects and respective brands. The list of normalisations includes:

Normalising styles for <html>, <body>
Adding font-smoothing to Mozilla and WebKit browsers
Reducing motion for users who have requested it
Normalising links
Normalising text related elements
Normalising form elements

Stacking with z-index

We recommend to avoid setting z-index. Where needed, Origami provide some standard values as Custom Properties. This help prevent conflicts within projects.

Stack without the z-index property where possible.
Aim to reduce z-index elsewhere, rather than raise your own z-index value.
Where z-index is required, use a standard value as below. Remember though, z-index is not a global value and only applies within a Stacking Context (mdn). You might find Josh W Comeau's What The Heck, z-index?? a good introduction.
--o3-z-index: To bump z-index for most elements, if z-index is unavoidable.
--o3-z-popover: Popovers which overlay content, such as select, autocomplete drop downs, calendar widgets, tooltips.
--o3-z-navigation-popover: Navigation which overlays content, such as sticky headers and drawers.
--o3-z-message-polite-popover: Non-modal, non-critical messaging overlays such as marketing banners.
--o3-z-message-service-popover: Non-modal, messaging overlays for important service or status messages such as toasts.
--o3-z-modal-dialog: Modal dialogue / overlays which prevent interaction with underlying content.

Where two elements fall into the same category and overlap, you may increment by one:

.navigation-drawer {
    z-index: calc(var(--o3-z-navigation-popover) + 1);
}

.navigation-sticky {
    z-index: var(--o3-z-navigation-popover);
}

Focus rings

o3-foundation provides focus rings in two styles.

A single outline by default, for example on anchor elements, which is unobtrusive.
A double focus ring for buttons and form elements, this ensures contrast regardless of the element colour and its background.

The double focus rings consist of two rings: an outer black ring and an inner white ring. By default, the outer ring is black and the inner ring is white. However, if you are using an inverse theme, the colors will be inverted.

If you need to apply a focus ring to a different element than the ones mentioned above, you can use the o3-apply-focus-ring class on that element.

Users can also revert the focus rings by using the o3-revert-focus class on the element.

Fonts

o3-foundation defines two @font-face-s. The first one is Metric2-VF and it is used fot all brands. The second one is FinancierDisplayWeb and currently used by core brand only.

Icons

CSS Custom Properties for icons are included for each brand in the format: --o3-icon-[ICON NAME].

The icon CSS Custom Property is a url() CSS function for the encoded icon SVG. It may be used anywhere url() may be used such as within background-image and mask.

For example, to create a 1rem sized icon which inherits its colour from the current text colour:

.example-icon-use {
    /* Create a square the size we want an icon */
    display: inline-block;
    width: 1rem;
    height: 1rem;
    /* Set the icon colour, In this case match the
     current foreground text colour. */
    background-color: currentColor;
    /* Mask the square with an Origami icon. */
    mask-image: var(--o3-icon-plus);
    mask-repeat: no-repeat;
    mask-size: contain;
}

See our documentation website for a full list of icons and more details.

Colours

o3-foundation provides CSS Custom Properties for 3 types of colours:

Palette: Base colours such as --o3-color-palette-paper, --o3-color-palette-teal.
Usecase: Semantic colours such as --o3-color-use-case-page-background, --o3-color-use-case-page-inverse-background.
Tints: Modified palette colours --o3-color-palette-black-10, --o3-color-palette-teal-100.

We recommend using a usecase token where one exists, as this allows us flexibility to update the underlying colour based on how it is used. However it is preferable to use a palette or tint colour directly rather than mis-use a usecase token.

Example:

.example-text {
    color: var(--o3-color-palette-black);
}

See our documentation website for a full list of colours and where to use them.

Spacing

o3-foundation provides CSS Custom Properties for standard spacing values in the format: --o3-spacing-[spacing size]. These follow t-shirt sizes from 5xs to 4xl.

Example:

.example-spacing {
    margin: var(--o3-spacing-2xs);
}

See our documentation website for a full list of spacing tokens.

Grid

The o3-grid system, provided by o3-foundation, standardises usage of grid across ft. The o3-grid is responsive on different screen sizes and differs from o-grid component. For more detailed guidelines on grid system check our documentation for o3-grid.

For a convenient and standardized grid layout, apply the o3-grid class to your element:

<div class="o3-grid">
    <!-- Grid Items -->
</div>

The o3-grid layout template follows a specific structure:

`bleed-start content-start [REST_OF_THE_COLUMNS] content-end bleed-end`,

The o3-grid system adapts to different screen sizes, the number of columns is variable according to viewport size, see design guidelines for details.

Content-area: The grid's main content area is defined by content-start and content-end boundaries.
Bleed Columns for Extended Layouts: bleed-start & bleed-end: These special columns extend beyond the 12-column grid, reaching the edges of the viewport. This allows you to create "full-bleed" layouts where content extends off the screen. These columns are used as margin areas, providing visual breathing room around your central content.
[REST_OF_THE_COLUMNS]: This represents any additional columns you might need in your grid.

Positioning grid items

You can precisely control the positioning of grid items using the grid-column style or css property:

<div class="o3-grid">
    <div style="grid-column: content-start / content-end;">
        Spans the entire content area
    </div>
    <div style="grid-column: content-start / span 4;">
        Starts at `content-start`, spans 4 columns
    </div>
    <div style="grid-column: content-start / span 2;">
        Starts at `content-start`, spans 2 columns
    </div>
    <div style="grid-column: span 1 / content-end;">
        Ends at `content-end`, spans 1 column back
    </div>
    <div style="grid-column: bleed-left / bleed-right;">
        Spans the entire viewport (full bleed)
    </div>
    <div style="grid-column: bleed-left / content-end;">
        Starts at the left edge, ends at `content-end`
    </div>
</div>

Using grid with nested children

In some cases, an element may be nested deeply and not have access to the grid. o3-foundation provides CSS Custom Properties to help align elements to grid in these cases:

.my-nested-class {
    --o3-grid-columns-to-span-count: 6;
    width: var(--o3-grid-columns-to-span-width);
}

Use --o3-grid-columns-to-span-count to control how many columns you want your element to span. In this example, the width of my-nested-class will be equivalent to 6 columns. --o3-grid-columns-to-span-count must be defined for .o3-grid-columns-to-span-width to work.

Advanced usage of grid

For advanced usage o3-foundation provides CSS Custom Properties for grid that you can set on your class:

.example-class {
    display: grid;
    /* Controls the column structure of your grid. */
    grid-template-columns: var(--o3-grid-template);
    /* Defines named areas for grid item placement. */
    grid-template-areas: var(--o3-grid-area);
    /* Manages the spacing between grid columns. */
    column-gap: var(--o3-grid-gap);
}

Helper classes

o3-foundation provides a set of helper classes to help with common tasks. The list of helper classes includes:

o3-visually-hidden: Hides an element visually, but leaves it available to screen readers
o3-box-sizing-border-box: Applies box-sizing: border-box to the current element and all its children

Migration

State	Major Version	Last Minor Release	Migration guide
✨ active	3	N/A	migrate to v3
╳ deprecated	2	2.3	migrate to v2
╳ deprecated	1	-	N/A

Contact

If you have any questions or comments about this component, or need help using it, please either raise an issue, visit #origami-support or email origami.support@ft.com.

Licence

This software is published by the Financial Times under the MIT licence.

Détail du package

@financial-times/o3-foundation

readme

o3-foundation

CSS Tokens

JS Tokens

Default export

Named export

Typography

List

HTML

JSX

Wrapper

HTML

Highlight (Bold)

Custom Properties

Max Line Width

Normalisation

Stacking with z-index

Focus rings

Fonts

Icons

Colours

Spacing

Grid

Positioning grid items

Using grid with nested children

Advanced usage of grid

Helper classes

Migration

Contact

Licence