Heading

Size and level are two different things. The level is <h1> to <h6> and decides the structure screen readers navigate by. data-size only decides how large the text looks.

How to use it

Example

Plain HTML

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@lo-tek/interfaces@0.40.0/src/tokens/tokens.css">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@lo-tek/interfaces@0.40.0/src/components/css/heading/heading.css">
<!-- Or everything in one file: https://cdn.jsdelivr.net/npm/@lo-tek/interfaces@0.40.0/dist/lotek.css -->

<h1 class="lt-heading" data-size="mega">Runner's policy terms</h1>
<h2 class="lt-heading" data-size="xl">About the policyholder</h2>
<h2 class="lt-heading">What we cover</h2>
<h3 class="lt-heading" data-size="m">Exclusions</h3>
<h4 class="lt-heading" data-size="s">Acts of God</h4>
<h5 class="lt-heading" data-size="xs">Last changed</h5>

TypeScript

import "@lo-tek/interfaces/tokens.css"
import "@lo-tek/interfaces/heading.css"

lt is used in two ways, and which one depends on whether you create the element or find it.

If you create the markup, spread the attributes in. That is the way in React, Astro and anything else that renders:

import { lt } from "@lo-tek/interfaces/react"

<h1 {...lt.heading({ size: "mega" })}>Runner's policy terms</h1>

The import is from /react here, since the block is JSX. From there the keys are className and htmlFor. In Astro and anything else without React, import @lo-tek/interfaces and you get class and for.

If the element is already there, set them on it. That is the way when you enhance HTML a server or a template has sent:

import { lt } from "@lo-tek/interfaces"

const title = document.querySelector<HTMLHeadingElement>("#section")

lt.setAttributes(title, lt.heading({ size: "m" }))

If the size comes from outside content, validate it with lt.heading.isSize(x). See Type-safe use.

kotlinx.html

// Once for the whole app, in the page template: every stylesheet, from the WebJar.
head { link(rel = "stylesheet", href = LotekWebJar.CSS) }

On a Kotlin or Java server, the same with kotlinx.html and lo-tek-kotlinx-html. The builder functions are in Lt, with an enum for each list of values:

import kotlinx.html.*
import no.lotek.*
import no.lotek.html.lt

fun FlowContent.terms() {
    h1 { lt(Lt.heading(size = HeadingSize.MEGA)); +"Runner's policy terms" }
    h2 { lt(Lt.heading(size = HeadingSize.XL)); +"About the policyholder" }
    h2 { lt(Lt.heading()); +"What we cover" }
    h3 { lt(Lt.heading(size = HeadingSize.M)); +"Exclusions" }
    h4 { lt(Lt.heading(size = HeadingSize.S)); +"Acts of God" }
    h5 { lt(Lt.heading(size = HeadingSize.XS)); +"Last changed" }
}

data-size	Font
mega	--lt-font-size-mega
xl	--lt-font-size-xxl
(omitted)	--lt-font-size-xl
m	--lt-font-size-l
s	--lt-font-size-m
xs	--lt-font-size-s, in capitals

Level follows the structure, not the look

An <h2> that should look small is correct. An <h4> chosen because it was small enough skips a level, and the table of contents the screen reader builds is then wrong:

<h2 class="lt-heading" data-size="s">The small print</h2>

The page should have one <h1>, and the levels below should follow each other without skipping.

Classes you can style

Class	What it is
.lt-heading	The heading. The size comes from data-size.

The sizes are the --lt-font-size tokens directly, so a change to the scale applies everywhere at once. Weight and line height are separate variables, because an organisation adopting the system often has its own typography:

Variable	Default
--lt-heading-font-weight	var(--lt-font-weight-bold)
--lt-heading-line-height	var(--lt-line-height-heading)

The headings use text-wrap: balance, so a heading over two lines does not end with a single word on the last one.

See Customising for how the layer works.

Accessibility

• Screen readers can list every heading and jump between them. That is the most common way to find your way around a long page.
• Do not use a heading to make text large. Use Paragraph with data-size="large".
• A heading with no content below it is not a heading.