Button progress

A button that fills while the work runs, loops its icon until the work stops, and shows a receipt. As a download and as an upload.

Take it with you

This demo also exists as a standalone project — npm install && npm run dev, no changes needed.

npx giget@latest gh:lordicondev/ui-components/button-progress#standalone button-progress

Copies the button-progress folder of the standalone branch — where every demo lives on its own — into ./button-progress.

How it works

Define the element, put the icon in the markup, set the control's state. Then the parts that make this demo different.

Define the element Built-in triggers only. What each icon follows is written in its markup.

import { defineElement } from '@lordicon/element';

// Registers <lord-icon> with its built-in triggers. The markup says what each icon follows.
defineElement();

import { defineElement } from '@lordicon/element';

// Registers <lord-icon> with its built-in triggers. The markup says what each icon follows.
defineElement();

The button data-stage for what it is doing, data-progress for how far. The icon maps each stage to a state.

html

<!-- data-stage is the state: the icon, the fill, the label and the toast read
     it. data-progress is 0 to 100 and the bar follows it. -->
<button
    class="task__button"
    type="button"
    data-stage="idle"
    data-progress="0"
    aria-label="Download file"
>
    <span class="task__fill" aria-hidden="true"></span>

    <lord-icon
        class="task__mark"
        current-color
        src="icons/download.json"
        loading="interaction"
        trigger="follow(data-stage, busy=loop-cycle, done=morph-check)"
        target=".task__button"
        state="morph-check"
        aria-hidden="true"
    >
        <img alt="" src="icons/download.svg" />
    </lord-icon>
    <!-- … -->
</button>

Set progress and stage Two attributes. Everything on screen reads them.

/**
 * Progress from 0 to 100. An attribute, so anything can drive it: this demo's pretend
 * transfer, a real `onprogress`, or the element inspector. The stylesheet reads
 * `--progress`, because CSS cannot take a number out of an attribute.
 */
function report(percent: number): void {
    const bounded = Math.min(Math.max(percent, 0), 100);

    button.dataset.progress = String(Math.round(bounded));
    button.style.setProperty('--progress', String(bounded / 100));
}

/** Sets the stage: idle, busy or done. The icon, the bar, the label and the toast read it. */
function enter(stage: string): void {
    button.dataset.stage = stage;
    button.disabled = stage === 'busy';
    button.setAttribute('aria-busy', String(stage === 'busy'));

    say(STAGES.indexOf(stage));
}

/**
 * Progress from 0 to 100. An attribute, so anything can drive it: this demo's pretend
 * transfer, a real `onprogress`, or the element inspector. The stylesheet reads
 * `--progress`, because CSS cannot take a number out of an attribute.
 */
function report(percent) {
    const bounded = Math.min(Math.max(percent, 0), 100);

    button.dataset.progress = String(Math.round(bounded));
    button.style.setProperty('--progress', String(bounded / 100));
}

/** Sets the stage: idle, busy or done. The icon, the bar, the label and the toast read it. */
function enter(stage) {
    button.dataset.stage = stage;
    button.disabled = stage === 'busy';
    button.setAttribute('aria-busy', String(stage === 'busy'));

    say(STAGES.indexOf(stage));
}

One press, one cycle The pretend transfer. A real one would call report() from onprogress.

/** One press: busy with progress in steps, done, a receipt, then idle again. */
async function run(): Promise<void> {
    enter('busy');

    for (let percent = STEP; percent <= 100; percent += STEP) {
        report(percent);
        await wait(TRANSFER / (100 / STEP));
    }
    enter('done');

    toast.dataset.shown = 'true'; // the tick plays on this
    await wait(RECEIPT);

    toast.dataset.shown = 'false';
    await wait(200); // let the toast leave before the button resets
    enter('idle');
    report(0);
}

button.addEventListener('click', () => void run());

/** One press: busy with progress in steps, done, a receipt, then idle again. */
async function run() {
    enter('busy');

    for (let percent = STEP; percent <= 100; percent += STEP) {
        report(percent);
        await wait(TRANSFER / (100 / STEP));
    }
    enter('done');

    toast.dataset.shown = 'true'; // the tick plays on this
    await wait(RECEIPT);

    toast.dataset.shown = 'false';
    await wait(200); // let the toast leave before the button resets
    enter('idle');
    report(0);
}

button.addEventListener('click', () => void run());

Slide the label strip Always upwards. Wrapping uses a copy of the first label past the end.

/**
 * Slides the label strip to line `at`. The strip only ever moves up. Going back to the
 * first label, it slides on to the copy past the end, then jumps back to the real one
 * with transitions off.
 */
function say(at: number): void {
    const from = Number(strip.dataset.at ?? 0);
    const to = at === 0 && from > 0 ? lines.length : at;

    strip.dataset.at = String(at);
    strip.style.setProperty('--line', String(to));
    // The first text node only: the busy label ends in animated dots.
    button.setAttribute('aria-label', lines[at].firstChild!.textContent!.trim());

    if (to <= from) return;

    strip.addEventListener(
        'transitionend',
        () => {
            if (to !== lines.length) return;

            strip.dataset.settling = '';
            strip.style.setProperty('--line', '0');
            void strip.offsetWidth; // apply the jump now, while transitions are off
            delete strip.dataset.settling;
        },
        { once: true },
    );
}

/**
 * Slides the label strip to line `at`. The strip only ever moves up. Going back to the
 * first label, it slides on to the copy past the end, then jumps back to the real one
 * with transitions off.
 */
function say(at) {
    const from = Number(strip.dataset.at ?? 0);
    const to = at === 0 && from > 0 ? lines.length : at;

    strip.dataset.at = String(at);
    strip.style.setProperty('--line', String(to));
    // The first text node only: the busy label ends in animated dots.
    button.setAttribute('aria-label', lines[at].firstChild.textContent.trim());

    if (to <= from) return;

    strip.addEventListener(
        'transitionend',
        () => {
            if (to !== lines.length) return;

            strip.dataset.settling = '';
            strip.style.setProperty('--line', '0');
            void strip.offsetWidth; // apply the jump now, while transitions are off
            delete strip.dataset.settling;
        },
        { once: true },
    );
}

The progress bar Scaled, not widened. The transition smooths the steps; done fades it out.

css

/* The bar is the full width of the button, scaled by --progress. Scaling a solid colour
   costs no layout. When done it fades rather than running back; the scale resets while
   it is invisible. */
.task__fill {
    position: absolute;
    inset: 0;
    transform-origin: left;
    scale: var(--progress, 0) 1;
    background: var(--accent-strong);
    opacity: 0;
}

.task__button[data-stage='busy'] .task__fill {
    opacity: 1;
    transition: scale 220ms linear;
}

.task__button[data-stage='done'] .task__fill {
    opacity: 0;
    transition: opacity 300ms ease;
}

The receipt opening and leaving Opens from the middle to the edge. Leaves by fading; the box snaps back afterwards.

css

/* Opens from the button's middle (left 50%, width 0) to its left edge at full width.
   --toast-width is measured by main.ts, because width cannot transition to auto. The
   words are not animated; the box uncovers them. Leaving is a fade and a small drop;
   `0s 150ms` snaps width and left back once the fade has finished. */
.toast {
    left: 50%;
    width: 0;
    opacity: 0;
    translate: 0 0;
    transition:
        opacity 150ms ease,
        translate 150ms ease,
        width 0s 150ms,
        left 0s 150ms;
}

.toast[data-shown='true'] {
    width: var(--toast-width, max-content);
    left: 0;
    opacity: 1;
    transition:
        width 500ms cubic-bezier(0.215, 0.61, 0.355, 1),
        left 500ms cubic-bezier(0.215, 0.61, 0.355, 1),
        opacity 150ms ease;
}

Every file

The demo's own files, whole, at the paths the export uses.

button-progress.css 221 lines

css

@import '@shared/styles/index.css';
@import '@shared/ui/pager.css';

.demo {
    display: grid;
    grid-template-rows: 1fr auto;
    justify-items: center;
    align-items: center;
    gap: var(--space-96);
    min-height: 100dvh;
    padding: var(--space-64) var(--gutter) var(--space-32);
}

/* The box the toast is positioned against. */
.task {
    position: relative;
    display: grid;
    justify-items: start;
}

.task__button {
    position: relative;
    display: flex;
    align-items: center;
    gap: var(--space-4);
    overflow: hidden;
    padding: var(--space-8) var(--space-16);
    border: 0;
    border-radius: var(--radius-md);
    background: var(--accent);
    box-shadow: var(--shadow-accent);
    color: var(--ink-inverse);
    --icon-filter: var(--filter-ink-inverse);
    font-weight: 500;
    cursor: pointer;
}

/* No transition on hover or press. The icon holds still through both. */
.task__button:hover:not(:disabled) {
    background: var(--accent-strong);
}

.task__button:active:not(:disabled) {
    background: var(--accent-ink);
}

.task__button:disabled {
    cursor: default;
}

/* The bar is the full width of the button, scaled by --progress. Scaling a solid colour
   costs no layout. When done it fades rather than running back; the scale resets while
   it is invisible. */
.task__fill {
    position: absolute;
    inset: 0;
    transform-origin: left;
    scale: var(--progress, 0) 1;
    background: var(--accent-strong);
    opacity: 0;
}

.task__button[data-stage='busy'] .task__fill {
    opacity: 1;
    transition: scale 220ms linear;
}

.task__button[data-stage='done'] .task__fill {
    opacity: 0;
    transition: opacity 300ms ease;
}

.task__mark {
    flex: none;
    width: var(--icon-size-24);
    height: var(--icon-size-24);
}

/* A one-line window over a strip of labels. The window is as wide as the widest label,
   so the button keeps its width while the words change. */
.task__says {
    display: block;
    overflow: hidden;
    height: var(--leading-base);
}

.task__lines {
    display: grid;
    justify-items: start;
    translate: 0 calc(var(--line, 0) * var(--leading-base) * -1);
    transition: translate 250ms ease-out;
}

.task__line {
    line-height: var(--leading-base);
    white-space: nowrap;
}

/* The three dots after "Downloading" appear one at a time and vanish together, on a
   667ms cycle from the reference recording. They only change opacity, so nothing moves. */
.task__dots {
    font-style: normal;
}

.task__dots > i::before {
    content: '.';
    font-style: normal;
}

/* Longhands, not the `animation` shorthand: a shorthand without a name minifies to
   `animation: none` and drops the timings. */
.task__dots > i {
    opacity: 0;
    animation-duration: 667ms;
    animation-timing-function: step-end;
    animation-iteration-count: infinite;
}

.task__dots > i:nth-child(1) {
    animation-name: dot-one;
}

.task__dots > i:nth-child(2) {
    animation-name: dot-two;
}

.task__dots > i:nth-child(3) {
    animation-name: dot-three;
}

@keyframes dot-one {
    22.5% {
        opacity: 1;
    }
}

@keyframes dot-two {
    45% {
        opacity: 1;
    }
}

@keyframes dot-three {
    67.5% {
        opacity: 1;
    }
}

/* The jump back to the first label, taken with transitions off. */
.task__lines[data-settling] {
    transition: none;
}

/* The receipt under the button. Absolute, so nothing below moves to make room. */
.toast {
    position: absolute;
    top: calc(100% + var(--space-16) + var(--space-4));
    z-index: 1;
    display: flex;
    align-items: center;
    gap: var(--space-8);
    margin: 0;
    overflow: hidden;
    padding: var(--space-8);
    border: 1px solid var(--border-soft);
    border-radius: var(--radius-lg);
    background: var(--surface);
}

/* Opens from the button's middle (left 50%, width 0) to its left edge at full width.
   --toast-width is measured by main.ts, because width cannot transition to auto. The
   words are not animated; the box uncovers them. Leaving is a fade and a small drop;
   `0s 150ms` snaps width and left back once the fade has finished. */
.toast {
    left: 50%;
    width: 0;
    opacity: 0;
    translate: 0 0;
    transition:
        opacity 150ms ease,
        translate 150ms ease,
        width 0s 150ms,
        left 0s 150ms;
}

.toast[data-shown='true'] {
    width: var(--toast-width, max-content);
    left: 0;
    opacity: 1;
    transition:
        width 500ms cubic-bezier(0.215, 0.61, 0.355, 1),
        left 500ms cubic-bezier(0.215, 0.61, 0.355, 1),
        opacity 150ms ease;
}

.toast[data-shown='false'] {
    translate: 0 var(--space-8);
}

.toast__mark {
    flex: none;
    width: var(--icon-size-20);
    height: var(--icon-size-20);
    color: var(--accent);
}

.toast__text {
    color: var(--ink);
    font-size: var(--text-sm);
    font-weight: 500;
    line-height: var(--leading-base);
    white-space: nowrap;
}

@media (prefers-reduced-motion: reduce) {
    .task__lines,
    .task__fill,
    .toast {
        transition: none;
    }
}

index.html 131 lines

html

<!doctype html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1" />
        <title>Button progress</title>
        <link rel="stylesheet" href="./button-progress.css" />
        <script type="module" src="./main.ts"></script>
    </head>
    <body>
        <main class="demo">
            <div class="task" id="kind-download" data-page>
                <!-- data-stage is the state: the icon, the fill, the label and the toast read
                     it. data-progress is 0 to 100 and the bar follows it. -->
                <button
                    class="task__button"
                    type="button"
                    data-stage="idle"
                    data-progress="0"
                    aria-label="Download file"
                >
                    <span class="task__fill" aria-hidden="true"></span>

                    <lord-icon
                        class="task__mark"
                        current-color
                        src="icons/download.json"
                        loading="interaction"
                        trigger="follow(data-stage, busy=loop-cycle, done=morph-check)"
                        target=".task__button"
                        state="morph-check"
                        aria-hidden="true"
                    >
                        <img alt="" src="icons/download.svg" />
                    </lord-icon>

                    <!-- Three labels on a strip that slides up one line per stage change.
                         aria-label on the button is copied from whichever is showing. -->
                    <span class="task__says" aria-hidden="true">
                        <span class="task__lines">
                            <span class="task__line">Download file</span>
                            <span class="task__line"
                                >Downloading<i class="task__dots"><i></i><i></i><i></i></i
                            ></span>
                            <span class="task__line">Downloaded</span>
                        </span>
                    </span>
                </button>

                <!-- Absolutely placed, so nothing below moves to make room. -->
                <p class="toast" role="status" data-shown="false">
                    <lord-icon
                        class="toast__mark"
                        current-color
                        src="icons/check-circle.json"
                        trigger="follow(data-shown)"
                        target=".toast"
                        state="in-reveal"
                        aria-hidden="true"
                    ></lord-icon>

                    <span class="toast__text">File downloaded – lordicon-icons.zip</span>
                </p>
            </div>

            <div class="task" id="kind-upload" data-page hidden>
                <button
                    class="task__button"
                    type="button"
                    data-stage="idle"
                    data-progress="0"
                    aria-label="Upload file"
                >
                    <span class="task__fill" aria-hidden="true"></span>

                    <!-- The second page: a different icon and three different words. -->
                    <lord-icon
                        class="task__mark"
                        current-color
                        src="icons/upload.json"
                        trigger="follow(data-stage, busy=loop-cycle, done=morph-check)"
                        target=".task__button"
                        state="morph-check"
                        aria-hidden="true"
                    ></lord-icon>

                    <span class="task__says" aria-hidden="true">
                        <span class="task__lines">
                            <span class="task__line">Upload file</span>
                            <span class="task__line"
                                >Uploading<i class="task__dots"><i></i><i></i><i></i></i
                            ></span>
                            <span class="task__line">Uploaded</span>
                        </span>
                    </span>
                </button>

                <p class="toast" role="status" data-shown="false">
                    <lord-icon
                        class="toast__mark"
                        current-color
                        src="icons/check-circle.json"
                        trigger="follow(data-shown)"
                        target=".toast"
                        state="in-reveal"
                        aria-hidden="true"
                    ></lord-icon>

                    <span class="toast__text">File uploaded – icon-heart.json</span>
                </p>
            </div>

            <div class="pager">
                <button
                    class="pager__dot"
                    type="button"
                    aria-pressed="true"
                    aria-controls="kind-download"
                    aria-label="Download"
                ></button>
                <button
                    class="pager__dot"
                    type="button"
                    aria-pressed="false"
                    aria-controls="kind-upload"
                    aria-label="Upload"
                ></button>
            </div>
        </main>
    </body>
</html>

main.ts 124 lines

import { defineElement } from '@lordicon/element';

// Registers <lord-icon> with its built-in triggers. The markup says what each icon follows.
defineElement();

import { pager } from '@shared/ui/pager.ts';

const STAGES = ['idle', 'busy', 'done'];

/** How long the pretend transfer takes, how much lands per step, and how long the receipt stays. */
const TRANSFER = 2200;
const STEP = 10;
const RECEIPT = 2000;

const wait = (ms: number) => new Promise((done) => setTimeout(done, ms));

/**
 * Wires one `.task`: the button, its label strip and its toast. Called for each task on
 * the page; the download and the upload differ only in markup.
 */
function wire(task: HTMLElement): void {
    const button = task.querySelector<HTMLButtonElement>('.task__button')!;
    const strip = task.querySelector<HTMLElement>('.task__lines')!;
    const lines = [...task.querySelectorAll<HTMLElement>('.task__line')];
    const toast = task.querySelector<HTMLElement>('.toast')!;

    // A copy of the first label after the last one, so the strip can wrap forwards.
    strip.append(lines[0].cloneNode(true));

    /**
     * Progress from 0 to 100. An attribute, so anything can drive it: this demo's pretend
     * transfer, a real `onprogress`, or the element inspector. The stylesheet reads
     * `--progress`, because CSS cannot take a number out of an attribute.
     */
    function report(percent: number): void {
        const bounded = Math.min(Math.max(percent, 0), 100);

        button.dataset.progress = String(Math.round(bounded));
        button.style.setProperty('--progress', String(bounded / 100));
    }

    /** Sets the stage: idle, busy or done. The icon, the bar, the label and the toast read it. */
    function enter(stage: string): void {
        button.dataset.stage = stage;
        button.disabled = stage === 'busy';
        button.setAttribute('aria-busy', String(stage === 'busy'));

        say(STAGES.indexOf(stage));
    }

    /**
     * Slides the label strip to line `at`. The strip only ever moves up. Going back to the
     * first label, it slides on to the copy past the end, then jumps back to the real one
     * with transitions off.
     */
    function say(at: number): void {
        const from = Number(strip.dataset.at ?? 0);
        const to = at === 0 && from > 0 ? lines.length : at;

        strip.dataset.at = String(at);
        strip.style.setProperty('--line', String(to));
        // The first text node only: the busy label ends in animated dots.
        button.setAttribute('aria-label', lines[at].firstChild!.textContent!.trim());

        if (to <= from) return;

        strip.addEventListener(
            'transitionend',
            () => {
                if (to !== lines.length) return;

                strip.dataset.settling = '';
                strip.style.setProperty('--line', '0');
                void strip.offsetWidth; // apply the jump now, while transitions are off
                delete strip.dataset.settling;
            },
            { once: true },
        );
    }

    /** One press: busy with progress in steps, done, a receipt, then idle again. */
    async function run(): Promise<void> {
        enter('busy');

        for (let percent = STEP; percent <= 100; percent += STEP) {
            report(percent);
            await wait(TRANSFER / (100 / STEP));
        }
        enter('done');

        toast.dataset.shown = 'true'; // the tick plays on this
        await wait(RECEIPT);

        toast.dataset.shown = 'false';
        await wait(200); // let the toast leave before the button resets
        enter('idle');
        report(0);
    }

    button.addEventListener('click', () => void run());
}

/**
 * Measures each toast's open width once the font has loaded, because CSS cannot
 * transition width to `auto`. A hidden page has no widths, so it is shown for the
 * measurement; nothing paints in between.
 */
async function measure(): Promise<void> {
    await document.fonts.ready;

    for (const toast of document.querySelectorAll<HTMLElement>('.toast')) {
        const page = toast.closest<HTMLElement>('[data-page]')!;
        const away = page.hidden;

        page.hidden = false;
        toast.style.setProperty('--toast-width', `${toast.scrollWidth}px`);
        page.hidden = away;
    }
}

for (const task of document.querySelectorAll<HTMLElement>('.task')) wire(task);

pager();
void measure();

import { defineElement } from '@lordicon/element';

// Registers <lord-icon> with its built-in triggers. The markup says what each icon follows.
defineElement();

import { pager } from '@shared/ui/pager.js';

const STAGES = ['idle', 'busy', 'done'];

/** How long the pretend transfer takes, how much lands per step, and how long the receipt stays. */
const TRANSFER = 2200;
const STEP = 10;
const RECEIPT = 2000;

const wait = (ms) => new Promise((done) => setTimeout(done, ms));

/**
 * Wires one `.task`: the button, its label strip and its toast. Called for each task on
 * the page; the download and the upload differ only in markup.
 */
function wire(task) {
    const button = task.querySelector('.task__button');
    const strip = task.querySelector('.task__lines');
    const lines = [...task.querySelectorAll('.task__line')];
    const toast = task.querySelector('.toast');

    // A copy of the first label after the last one, so the strip can wrap forwards.
    strip.append(lines[0].cloneNode(true));

    /**
     * Progress from 0 to 100. An attribute, so anything can drive it: this demo's pretend
     * transfer, a real `onprogress`, or the element inspector. The stylesheet reads
     * `--progress`, because CSS cannot take a number out of an attribute.
     */
    function report(percent) {
        const bounded = Math.min(Math.max(percent, 0), 100);

        button.dataset.progress = String(Math.round(bounded));
        button.style.setProperty('--progress', String(bounded / 100));
    }

    /** Sets the stage: idle, busy or done. The icon, the bar, the label and the toast read it. */
    function enter(stage) {
        button.dataset.stage = stage;
        button.disabled = stage === 'busy';
        button.setAttribute('aria-busy', String(stage === 'busy'));

        say(STAGES.indexOf(stage));
    }

    /**
     * Slides the label strip to line `at`. The strip only ever moves up. Going back to the
     * first label, it slides on to the copy past the end, then jumps back to the real one
     * with transitions off.
     */
    function say(at) {
        const from = Number(strip.dataset.at ?? 0);
        const to = at === 0 && from > 0 ? lines.length : at;

        strip.dataset.at = String(at);
        strip.style.setProperty('--line', String(to));
        // The first text node only: the busy label ends in animated dots.
        button.setAttribute('aria-label', lines[at].firstChild.textContent.trim());

        if (to <= from) return;

        strip.addEventListener(
            'transitionend',
            () => {
                if (to !== lines.length) return;

                strip.dataset.settling = '';
                strip.style.setProperty('--line', '0');
                void strip.offsetWidth; // apply the jump now, while transitions are off
                delete strip.dataset.settling;
            },
            { once: true },
        );
    }

    /** One press: busy with progress in steps, done, a receipt, then idle again. */
    async function run() {
        enter('busy');

        for (let percent = STEP; percent <= 100; percent += STEP) {
            report(percent);
            await wait(TRANSFER / (100 / STEP));
        }
        enter('done');

        toast.dataset.shown = 'true'; // the tick plays on this
        await wait(RECEIPT);

        toast.dataset.shown = 'false';
        await wait(200); // let the toast leave before the button resets
        enter('idle');
        report(0);
    }

    button.addEventListener('click', () => void run());
}

/**
 * Measures each toast's open width once the font has loaded, because CSS cannot
 * transition width to `auto`. A hidden page has no widths, so it is shown for the
 * measurement; nothing paints in between.
 */
async function measure() {
    await document.fonts.ready;

    for (const toast of document.querySelectorAll('.toast')) {
        const page = toast.closest('[data-page]');
        const away = page.hidden;

        page.hidden = false;
        toast.style.setProperty('--toast-width', `${toast.scrollWidth}px`);
        page.hidden = away;
    }
}

for (const task of document.querySelectorAll('.task')) wire(task);

pager();
void measure();

What it imports 6 shared files

shared/styles/base.css 115 lines

css

/*
 * Fonts, reset and default typography. Nothing control-specific: every demo styles its
 * own control. Only the UI face is here; the mono face is the portal's.
 */
@font-face {
    font-family: 'Figtree';
    font-style: normal;
    font-weight: 300 900;
    font-display: swap;
    src: url('../fonts/figtree-latin.woff2') format('woff2');
    unicode-range:
        U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308,
        U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

@font-face {
    font-family: 'Figtree';
    font-style: normal;
    font-weight: 300 900;
    font-display: swap;
    src: url('../fonts/figtree-latin-ext.woff2') format('woff2');
    unicode-range:
        U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329,
        U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113,
        U+2C60-2C7F, U+A720-A7FF;
}

/* Arial with Figtree's measurements, for the moment before Figtree arrives, so the text does
   not move when it does. Measured on Figtree at 400 and 500. */
@font-face {
    font-family: 'Figtree fallback';
    src: local('Arial'), local('Liberation Sans');
    size-adjust: 100.3%;
    ascent-override: 94.7%;
    descent-override: 24.9%;
    line-gap-override: 0%;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

/* An author `display` on a component would beat the UA rule for [hidden], and then
   `el.hidden = true` would stop working. Settled once here. */
[hidden] {
    display: none !important;
}

body {
    margin: 0;
    background: var(--surface);
    color: var(--ink);
    --icon-filter: var(--filter-ink);
    font-family: var(--font-ui);
    font-size: var(--text-base);
    line-height: var(--leading-base);
    -webkit-font-smoothing: antialiased;
}

button,
input,
textarea,
select {
    font: inherit;
    color: inherit;
}

/* A second click on a button would otherwise select its label. */
button {
    -webkit-user-select: none;
    user-select: none;
}

:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/*
 * In the accessibility tree but not on screen: labels and legends that the visual design
 * has no room for. Clipped rather than `display: none`, which would remove it from the
 * tree too, and it also hides live radio inputs that must stay reachable by keyboard.
 */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
    white-space: nowrap;
}

/*
 * Until the script defines <lord-icon> it is an unknown inline element with no size. These
 * rules give it the box it will have, so nothing moves when it is defined.
 */
lord-icon {
    display: inline-block;
    width: var(--icon-size-32);
    height: var(--icon-size-32);
}

/* A placeholder inside the icon fills it until the icon is ready. */
lord-icon:not(:defined) > img {
    display: block;
    width: 100%;
    height: 100%;
}

/* Placeholders are black. Set --icon-filter wherever an icon's colour is set. */
lord-icon > img {
    filter: var(--icon-filter);
}

shared/styles/index.css 4 lines

css

/* The one stylesheet a demo imports. */
@import './palette.css';
@import './tokens.css';
@import './base.css';

shared/styles/palette.css 87 lines

css

/*
 * Generated from the Figma token export.
 * Raw values only — roles live in tokens.css. Edit the Figma variables, not this file.
 */
:root {
    /* color/ink */
    --gray-0: #FFFFFF;
    --gray-50: #F7F8FA;
    --gray-100: #EEF0F3;
    --gray-200: #DEE1E6;
    --gray-300: #C3C7D0;
    --gray-400: #9BA1AD;
    --gray-500: #767C89;
    --gray-600: #565C68;
    --gray-700: #3D414B;
    --gray-800: #282B33;
    --gray-900: #16181D;
    --gray-950: #0A0B0E;

    /* color/signal */
    --brand-100: #FFEEE9;
    --brand-200: #FFD7CA;
    --brand-300: #FFB199;
    --brand-400: #FF7D5C;
    --brand-500: #FF5A36;
    --brand-600: #E8431F;
    --brand-700: #C2340F;

    /* color/success */
    --green-100: #EDF9F1;
    --green-300: #A7D9BC;
    --green-700: #15803D;

    /* color/error */
    --red-100: #FDECEC;
    --red-300: #F5B5B5;
    --red-700: #DC2626;

    /* typography/font */
    --font-ui-name: 'Figtree';
    --font-mono-name: 'JetBrains Mono';

    /* typography/size */
    --text-xs: 12px;
    --text-sm: 14px;
    --text-base: 16px;
    --text-lg: 20px;
    --text-xl: 24px;
    --text-2xl: 32px;
    --text-3xl: 40px;

    /* typography/lineHeight */
    --leading-xs: 16px;
    --leading-sm: 20px;
    --leading-base: 24px;
    --leading-lg: 28px;
    --leading-xl: 32px;
    --leading-2xl: 40px;
    --leading-3xl: 48px;

    /* spacing (named after the value, the Figma scale is non-linear) */
    --space-4: 4px;
    --space-8: 8px;
    --space-12: 12px;
    --space-16: 16px;
    --space-24: 24px;
    --space-32: 32px;
    --space-48: 48px;
    --space-64: 64px;
    --space-96: 96px;

    /* size/icon */
    --icon-size-16: 16px;
    --icon-size-20: 20px;
    --icon-size-24: 24px;
    --icon-size-32: 32px;
    --icon-size-40: 40px;
    --icon-size-48: 48px;
    --icon-size-64: 64px;
    --icon-size-96: 96px;

    /* radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-pill: 9999px;
}

shared/styles/tokens.css 93 lines

css

/*
 * Design tokens by role. Raw values come from palette.css (generated); which grey is a
 * border and which is muted text is decided here, and so would a dark mode be.
 */
:root {
    /* Text. `--ink*` is always a colour; `--text-*` is always a size. */
    --ink: var(--gray-950);
    /* Text that reads as done or in progress, a step lighter than a heading. */
    --ink-strong: var(--gray-800);
    /* Body copy: a step down from --ink. */
    --ink-soft: var(--gray-600);
    --ink-muted: var(--gray-500);
    --ink-subtle: var(--gray-400);
    /* What has not started yet. */
    --ink-faint: var(--gray-300);
    --ink-inverse: var(--gray-0);

    /* Backgrounds */
    --surface: var(--gray-0);
    --surface-muted: var(--gray-50);
    /* A well inside a surface: the filled shape a single icon sits in. */
    --surface-sunken: var(--gray-100);

    /* Outlines */
    --border: var(--gray-200);
    /* The edge of a box that already has a fill, such as an input. */
    --border-soft: var(--gray-100);
    --border-strong: var(--gray-300);
    --border-accent: var(--brand-400);

    /* Brand accent */
    --accent: var(--brand-500);
    --accent-strong: var(--brand-600);
    --accent-surface: var(--brand-100);
    /* The outline of a tinted box, or a small shape on one. */
    --accent-border: var(--brand-300);
    /* Text or a mark on either of the above. */
    --accent-ink: var(--brand-700);

    /* Status. Warning rides the brand ramp — that is what the designs use. */
    --success: var(--green-700);
    --success-surface: var(--green-100);
    --success-border: var(--green-300);

    --warning: var(--brand-500);
    --warning-surface: var(--brand-100);
    --warning-border: var(--brand-300);

    --danger: var(--red-700);
    --danger-surface: var(--red-100);
    --danger-border: var(--red-300);

    /* Icons. Fed straight into --lord-icon-* by the demos. */
    --icon-color: var(--gray-950);
    --icon-accent: var(--brand-500);

    /* Icon placeholders are black SVGs. Each filter turns black into the colour of the same
       name. Made with a CSS filter generator: make a new one when its colour changes. */
    --filter-ink: invert(2%) sepia(4%) saturate(4817%) hue-rotate(193deg) brightness(114%)
        contrast(96%);
    --filter-ink-soft: invert(33%) sepia(18%) saturate(323%) hue-rotate(182deg) brightness(100%)
        contrast(90%);
    --filter-ink-muted: invert(55%) sepia(23%) saturate(191%) hue-rotate(181deg) brightness(84%)
        contrast(89%);
    --filter-ink-subtle: invert(70%) sepia(11%) saturate(284%) hue-rotate(181deg) brightness(91%)
        contrast(86%);
    --filter-ink-faint: invert(76%) sepia(17%) saturate(99%) hue-rotate(184deg) brightness(99%)
        contrast(100%);
    --filter-ink-inverse: invert(100%);
    --filter-accent: invert(49%) sepia(65%) saturate(3508%) hue-rotate(337deg) brightness(106%)
        contrast(113%);
    --filter-accent-strong: invert(29%) sepia(85%) saturate(1790%) hue-rotate(350deg)
        brightness(94%) contrast(93%);
    --filter-success: invert(38%) sepia(22%) saturate(2045%) hue-rotate(94deg) brightness(92%)
        contrast(84%);
    --filter-warning: var(--filter-accent);
    --filter-danger: invert(48%) sepia(74%) saturate(7139%) hue-rotate(343deg) brightness(84%)
        contrast(105%);

    /* Type stacks. The families themselves are in palette.css. */
    --font-ui:
        var(--font-ui-name), 'Figtree fallback', -apple-system, BlinkMacSystemFont, 'Segoe UI',
        Roboto, sans-serif;
    --font-mono: var(--font-mono-name), ui-monospace, SFMono-Regular, Menlo, monospace;

    /* Side padding of a page. The portal uses the same value, so demo and text line up. */
    --gutter: clamp(var(--space-16), 5vw, var(--space-48));

    /* A card's halo: no offset, so it reads as lift rather than as a light source. */
    --shadow-sm: 0 0 7.5px color-mix(in srgb, var(--gray-400) 20%, transparent);
    /* The same halo under a brand-coloured element. */
    --shadow-accent: 0 0 7.5px color-mix(in srgb, var(--accent-strong) 40%, transparent);
}

shared/ui/pager.css 40 lines

css

/* The dots that page between the parts of a demo. Where they sit is the demo's business. */
.pager {
    display: flex;
    gap: var(--space-4);
}

/* A small dot inside a button big enough to hit. */
.pager__dot {
    display: grid;
    place-items: center;
    width: var(--space-24);
    height: var(--space-24);
    padding: 0;
    border: 0;
    background: none;
    cursor: pointer;
}

.pager__dot::before {
    content: '';
    width: var(--space-8);
    height: var(--space-8);
    border-radius: var(--radius-pill);
    background: var(--border-strong);
    transition: background 150ms ease;
}

.pager__dot:hover::before {
    background: var(--ink-subtle);
}

.pager__dot[aria-pressed='true']::before {
    background: var(--accent);
}

@media (prefers-reduced-motion: reduce) {
    .pager__dot::before {
        transition: none;
    }
}

shared/ui/pager.ts 21 lines

/**
 * Dots that switch between the parts of one demo. Demo scaffolding, not a control: it
 * exists so a demo can show three variants of a component without stacking them.
 *
 * Parts carry `data-page`, dots carry `.pager__dot`, both in source order. A hidden page is
 * out of the tab order and the accessibility tree.
 */
export function pager(root: ParentNode = document): (shown: number) => void {
    const pages = [...root.querySelectorAll<HTMLElement>('[data-page]')];
    const dots = [...root.querySelectorAll<HTMLButtonElement>('.pager__dot')];

    const show = (shown: number) => {
        pages.forEach((page, at) => (page.hidden = at !== shown));
        dots.forEach((dot, at) => dot.setAttribute('aria-pressed', String(at === shown)));
    };

    dots.forEach((dot, at) => dot.addEventListener('click', () => show(at)));
    show(0);

    return show;
}

/**
 * Dots that switch between the parts of one demo. Demo scaffolding, not a control: it
 * exists so a demo can show three variants of a component without stacking them.
 *
 * Parts carry `data-page`, dots carry `.pager__dot`, both in source order. A hidden page is
 * out of the tab order and the accessibility tree.
 */
export function pager(root = document) {
    const pages = [...root.querySelectorAll('[data-page]')];
    const dots = [...root.querySelectorAll('.pager__dot')];

    const show = (shown) => {
        pages.forEach((page, at) => (page.hidden = at !== shown));
        dots.forEach((dot, at) => dot.setAttribute('aria-pressed', String(at === shown)));
    };

    dots.forEach((dot, at) => dot.addEventListener('click', () => show(at)));
    show(0);

    return show;
}

Icons

Hover a preview to play it. The icons are under the Lordicon License Terms, not the MIT licence of the code.

Preview	Used as	Lordicon icon
	`download`	system-outline-199-download (edited by hand)
	`upload`	system-outline-200-upload (edited by hand)
	`check-circle`	system-outline-24-check-circle (edited by hand)