Alerts

Four kinds of alert, and icons that greet the card they arrive on.

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/alert#standalone alert

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

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();

One alert card The icon watches the card it sits in, through target. The image inside shows until the icon is ready.

html

<!-- A kind is data-kind on the card. intro plays the icon once the card's
     own entrance has finished; hover plays it again. The image shows until
     the icon is ready. -->
<li class="alert" data-kind="info">
    <lord-icon
        class="alert__icon"
        current-color
        src="icons/info-circle.json"
        intro="hover-pinch, after=.alert"
        trigger="hover"
        target=".alert"
        aria-hidden="true"
    >
        <img alt="" src="icons/info-circle.svg" />
    </lord-icon>

    <!-- … -->
</li>

Fill a card in Sets data-kind and the icon's src. The deck is made of these.

/** One alert from the template, for the deck. The gallery's cards are in the markup. */
function build(kind: Kind): HTMLElement {
    const { icon, title, message } = CONTENT[kind];
    const alert = template.content.cloneNode(true) as DocumentFragment;
    const card = alert.querySelector<HTMLElement>('.alert')!;

    card.dataset.kind = kind;
    card.querySelector('.alert__icon')!.setAttribute('src', `icons/${icon}.json`);
    card.querySelector('.alert__title')!.textContent = title;
    card.querySelector('.alert__message')!.textContent = message;

    return card;
}

/** One alert from the template, for the deck. The gallery's cards are in the markup. */
function build(kind) {
    const { icon, title, message } = CONTENT[kind];
    const alert = template.content.cloneNode(true);
    const card = alert.querySelector('.alert');

    card.dataset.kind = kind;
    card.querySelector('.alert__icon').setAttribute('src', `icons/${icon}.json`);
    card.querySelector('.alert__title').textContent = title;
    card.querySelector('.alert__message').textContent = message;

    return card;
}

Queue the next alert Four kinds, then the button rests until one is dismissed.

/** The first kind not already in the deck, so dismissing one brings that kind back. */
function next(): Kind | undefined {
    const up = new Set(standing().map((card) => card.dataset.kind));
    return QUEUE.find((kind) => !up.has(kind));
}

function enqueue(): void {
    const kind = next();
    if (!kind) return;
    const card = build(kind);

    card.querySelector('.alert__close')!.addEventListener('click', () => void dismiss(card));

    queue.append(card);
    settle();
}

/** After any change: who sits where, and whether there is room for one more. */
function settle(): void {
    restack();
    add.disabled = !next();
}

/** The first kind not already in the deck, so dismissing one brings that kind back. */
function next() {
    const up = new Set(standing().map((card) => card.dataset.kind));
    return QUEUE.find((kind) => !up.has(kind));
}

function enqueue() {
    const kind = next();
    if (!kind) return;
    const card = build(kind);

    card.querySelector('.alert__close').addEventListener('click', () => void dismiss(card));

    queue.append(card);
    settle();
}

/** After any change: who sits where, and whether there is room for one more. */
function settle() {
    restack();
    add.disabled = !next();
}

Stack the deck and dismiss a card --depth per card drives the stylesheet. Dismissing waits for the transitions.

/** Writes each card's depth: the newest is 0 and in front, the rest recede behind it. */
function restack(): void {
    const cards = standing();

    cards.forEach((card, at) => {
        card.style.setProperty('--depth', String(cards.length - 1 - at));
        card.style.zIndex = String(at);
    });
}

/** Marks the card as leaving, lets the stylesheet animate it out, then removes it. */
async function dismiss(card: HTMLElement): Promise<void> {
    card.dataset.leaving = '';

    // Restack now, so the deck closes up while the card is still on its way out.
    settle();

    // The leaving transitions only exist once a frame has passed with the attribute set.
    await new Promise(requestAnimationFrame);
    await Promise.allSettled(card.getAnimations().map((leaving) => leaving.finished));

    card.remove();
    settle();
}

/** Writes each card's depth: the newest is 0 and in front, the rest recede behind it. */
function restack() {
    const cards = standing();

    cards.forEach((card, at) => {
        card.style.setProperty('--depth', String(cards.length - 1 - at));
        card.style.zIndex = String(at);
    });
}

/** Marks the card as leaving, lets the stylesheet animate it out, then removes it. */
async function dismiss(card) {
    card.dataset.leaving = '';

    // Restack now, so the deck closes up while the card is still on its way out.
    settle();

    // The leaving transitions only exist once a frame has passed with the attribute set.
    await new Promise(requestAnimationFrame);
    await Promise.allSettled(card.getAnimations().map((leaving) => leaving.finished));

    card.remove();
    settle();
}

The deck: position, size and fade from --depth translate and scale are separate properties, so they can take different times.

css

/* Position, size and fade are all functions of --depth. `translate` and `scale` are
   separate properties, so an arriving card climbs for 220ms while popping to full size
   in 60ms. Two cards show behind the front one; the third fades out. */
.stack .alert {
    --layer: min(var(--depth, 0), 2);
    translate: 0 calc(var(--layer) * 10px);
    scale: calc(1 - var(--layer) * 0.2);
    opacity: calc(1 - max(var(--depth, 0) - 1, 0));
    transition:
        translate 220ms cubic-bezier(0.2, 0.8, 0.3, 1),
        scale 60ms cubic-bezier(0, 0, 0.2, 1),
        opacity 60ms cubic-bezier(0, 0, 0.2, 1);
}

/* The cards behind settle more slowly than the new one arrives. */
.stack .alert:not(:last-child) {
    transition:
        translate 340ms cubic-bezier(0.3, 0, 0.2, 1),
        scale 340ms cubic-bezier(0.3, 0, 0.2, 1),
        opacity 340ms cubic-bezier(0.3, 0, 0.2, 1);
}

The way out A drop and a fade, over a deck that is already closing up.

css

/* A dismissed card drops on an accelerating curve and fades slowly enough to be seen
   going. The deck closes up behind it at the same time. */
.stack .alert[data-leaving] {
    z-index: 10;
    opacity: 0;
    scale: 0.96;
    translate: 0 16px;
    transition:
        translate 240ms cubic-bezier(0.4, 0, 1, 1),
        scale 240ms cubic-bezier(0.4, 0, 1, 1),
        opacity 200ms linear;
}

Every file

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

alert.css 236 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: stretch;
    gap: var(--space-48);
    min-height: 100dvh;
    padding: var(--space-64) var(--gutter) var(--space-32);
}

.page {
    display: grid;
    align-content: start;
    gap: var(--space-24);
    justify-items: center;
    width: 100%;
}

/* The deck sits mid-stage but behaves as if pinned to the bottom of a screen: cards
   arrive from below and recede downwards. */
.page--deck {
    align-content: center;
}

.add {
    justify-self: center;
    padding: var(--space-8) var(--space-16);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: var(--surface);
    font-size: var(--text-sm);
    font-weight: 500;
    cursor: pointer;
}

.add:hover:not(:disabled) {
    border-color: var(--border-strong);
}

.add:disabled {
    color: var(--ink-subtle);
    cursor: not-allowed;
}

.alerts {
    display: grid;
    gap: var(--space-16);
    width: 100%;
    max-width: 600px;
    margin: 0;
    padding: 0;
    list-style: none;
}

/* The card. Grey by default; a kind recolours it below. */
.alert {
    display: flex;
    align-items: flex-start;
    gap: var(--space-8);
    padding: var(--space-12);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    background: var(--surface-muted);
}

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

/* A kind is two colours on the card and one on the icon, which inherits `color`. */
.alert__icon {
    color: var(--ink-soft);
    --icon-filter: var(--filter-ink-soft);
}

.alert[data-kind='success'] {
    border-color: var(--success-border);
    background: var(--success-surface);
}

.alert[data-kind='success'] .alert__icon {
    color: var(--success);
    --icon-filter: var(--filter-success);
}

.alert[data-kind='warning'] {
    border-color: var(--warning-border);
    background: var(--warning-surface);
}

.alert[data-kind='warning'] .alert__icon {
    color: var(--warning);
    --icon-filter: var(--filter-warning);
}

.alert[data-kind='error'] {
    border-color: var(--danger-border);
    background: var(--danger-surface);
}

.alert[data-kind='error'] .alert__icon {
    color: var(--danger);
    --icon-filter: var(--filter-danger);
}

.alert__body {
    flex: 1;
    min-width: 0;
}

.alert__title {
    margin: 0;
    font-size: var(--text-sm);
    font-weight: 500;
    line-height: var(--leading-base);
}

.alert__message {
    margin: 0;
    color: var(--ink-soft);
    font-size: var(--text-sm);
    line-height: var(--leading-base);
}

.alert__close {
    flex: none;
    display: grid;
    padding: var(--space-4);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: none;
    color: var(--ink-soft);
    --icon-filter: var(--filter-ink-soft);
    cursor: pointer;
    place-items: center;
}

.alert__close:hover {
    border-color: var(--border-strong);
    color: var(--ink);
}

.alert__close-icon {
    width: var(--icon-size-16);
    height: var(--icon-size-16);
}

/* The queue is a deck: the newest card is in front, the rest recede behind it. main.ts
   writes --depth on each card; everything below follows from it. */
.stack {
    position: relative;
    /* Room for the tallest card plus the slivers under it. */
    min-height: 132px;
}

/* Anchored at the bottom, so cards of different heights show the same sliver behind. */
.stack .alert {
    position: absolute;
    inset-inline: 0;
    bottom: 20px;
    transform-origin: bottom center;
}

/* Position, size and fade are all functions of --depth. `translate` and `scale` are
   separate properties, so an arriving card climbs for 220ms while popping to full size
   in 60ms. Two cards show behind the front one; the third fades out. */
.stack .alert {
    --layer: min(var(--depth, 0), 2);
    translate: 0 calc(var(--layer) * 10px);
    scale: calc(1 - var(--layer) * 0.2);
    opacity: calc(1 - max(var(--depth, 0) - 1, 0));
    transition:
        translate 220ms cubic-bezier(0.2, 0.8, 0.3, 1),
        scale 60ms cubic-bezier(0, 0, 0.2, 1),
        opacity 60ms cubic-bezier(0, 0, 0.2, 1);
}

/* The cards behind settle more slowly than the new one arrives. */
.stack .alert:not(:last-child) {
    transition:
        translate 340ms cubic-bezier(0.3, 0, 0.2, 1),
        scale 340ms cubic-bezier(0.3, 0, 0.2, 1),
        opacity 340ms cubic-bezier(0.3, 0, 0.2, 1);
}

/* Where a new card starts from. */
@starting-style {
    .stack .alert {
        opacity: 0;
        scale: 0.9;
        translate: 0 24px;
    }
}

/* A dismissed card drops on an accelerating curve and fades slowly enough to be seen
   going. The deck closes up behind it at the same time. */
.stack .alert[data-leaving] {
    z-index: 10;
    opacity: 0;
    scale: 0.96;
    translate: 0 16px;
    transition:
        translate 240ms cubic-bezier(0.4, 0, 1, 1),
        scale 240ms cubic-bezier(0.4, 0, 1, 1),
        opacity 200ms linear;
}

/* Translucent cards in the deck, so the ones behind show through. */
.stack .alert {
    background: color-mix(in srgb, var(--surface-muted) 70%, transparent);
    -webkit-backdrop-filter: blur(5px) saturate(140%);
    backdrop-filter: blur(5px) saturate(140%);
}

.stack .alert[data-kind='success'] {
    background: color-mix(in srgb, var(--success-surface) 70%, transparent);
}

.stack .alert[data-kind='warning'] {
    background: color-mix(in srgb, var(--warning-surface) 70%, transparent);
}

.stack .alert[data-kind='error'] {
    background: color-mix(in srgb, var(--danger-surface) 70%, transparent);
}

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

index.html 233 lines

html

<!doctype html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1" />
        <title>Alerts</title>
        <link rel="stylesheet" href="./alert.css" />
        <script type="module" src="./main.ts"></script>
    </head>
    <body>
        <main class="demo">
            <section class="page" data-page aria-label="Every kind of alert">
                <!-- Every kind at once. The close buttons are not focusable: dismissing
                     belongs to the second page. -->
                <ul class="alerts">
                    <!-- A kind is data-kind on the card. intro plays the icon once the card's
                         own entrance has finished; hover plays it again. The image shows until
                         the icon is ready. -->
                    <li class="alert" data-kind="info">
                        <lord-icon
                            class="alert__icon"
                            current-color
                            src="icons/info-circle.json"
                            intro="hover-pinch, after=.alert"
                            trigger="hover"
                            target=".alert"
                            aria-hidden="true"
                        >
                            <img alt="" src="icons/info-circle.svg" />
                        </lord-icon>

                        <div class="alert__body">
                            <p class="alert__title">Scheduled maintenance</p>
                            <p class="alert__message">
                                Online banking will be unavailable Sunday 2–4 AM ET for scheduled
                                maintenance.
                            </p>
                        </div>

                        <button
                            class="alert__close"
                            type="button"
                            aria-label="Dismiss"
                            tabindex="-1"
                        >
                            <lord-icon
                                class="alert__close-icon"
                                current-color
                                src="icons/cross.json"
                                loading="interaction"
                                trigger="hover"
                                target=".alert__close"
                                aria-hidden="true"
                            >
                                <img alt="" src="icons/cross.svg" />
                            </lord-icon>
                        </button>
                    </li>
                    <li class="alert" data-kind="success">
                        <lord-icon
                            class="alert__icon"
                            current-color
                            src="icons/check-circle.json"
                            intro="hover-pinch, after=.alert"
                            trigger="hover"
                            target=".alert"
                            aria-hidden="true"
                        >
                            <img alt="" src="icons/check-circle.svg" />
                        </lord-icon>

                        <div class="alert__body">
                            <p class="alert__title">Transfer complete</p>
                            <p class="alert__message">
                                $1,250.00 was successfully sent to Alex Morgan.
                            </p>
                        </div>

                        <button
                            class="alert__close"
                            type="button"
                            aria-label="Dismiss"
                            tabindex="-1"
                        >
                            <lord-icon
                                class="alert__close-icon"
                                current-color
                                src="icons/cross.json"
                                loading="interaction"
                                trigger="hover"
                                target=".alert__close"
                                aria-hidden="true"
                            >
                                <img alt="" src="icons/cross.svg" />
                            </lord-icon>
                        </button>
                    </li>
                    <li class="alert" data-kind="warning">
                        <lord-icon
                            class="alert__icon"
                            current-color
                            src="icons/warning-triangle.json"
                            intro="hover-pinch, after=.alert"
                            trigger="hover"
                            target=".alert"
                            aria-hidden="true"
                        >
                            <img alt="" src="icons/warning-triangle.svg" />
                        </lord-icon>

                        <div class="alert__body">
                            <p class="alert__title">Low balance</p>
                            <p class="alert__message">
                                Your checking account is below $100. Consider transferring funds to
                                avoid overdraft.
                            </p>
                        </div>

                        <button
                            class="alert__close"
                            type="button"
                            aria-label="Dismiss"
                            tabindex="-1"
                        >
                            <lord-icon
                                class="alert__close-icon"
                                current-color
                                src="icons/cross.json"
                                loading="interaction"
                                trigger="hover"
                                target=".alert__close"
                                aria-hidden="true"
                            >
                                <img alt="" src="icons/cross.svg" />
                            </lord-icon>
                        </button>
                    </li>
                    <li class="alert" data-kind="error">
                        <lord-icon
                            class="alert__icon"
                            current-color
                            src="icons/cross-circle.json"
                            intro="hover-pinch, after=.alert"
                            trigger="hover"
                            target=".alert"
                            aria-hidden="true"
                        >
                            <img alt="" src="icons/cross-circle.svg" />
                        </lord-icon>

                        <div class="alert__body">
                            <p class="alert__title">Payment declined</p>
                            <p class="alert__message">
                                Your card ending in 4242 was declined. Check your details and try
                                again.
                            </p>
                        </div>

                        <button
                            class="alert__close"
                            type="button"
                            aria-label="Dismiss"
                            tabindex="-1"
                        >
                            <lord-icon
                                class="alert__close-icon"
                                current-color
                                src="icons/cross.json"
                                loading="interaction"
                                trigger="hover"
                                target=".alert__close"
                                aria-hidden="true"
                            >
                                <img alt="" src="icons/cross.svg" />
                            </lord-icon>
                        </button>
                    </li>
                </ul>
            </section>

            <section class="page page--deck" data-page aria-label="Alerts as they arrive" hidden>
                <ul class="alerts stack" data-list="queue" role="status" aria-live="polite"></ul>
                <button class="add" type="button" data-add>Show an alert</button>
            </section>

            <div class="pager">
                <button
                    class="pager__dot"
                    type="button"
                    aria-pressed="true"
                    aria-label="Every kind of alert"
                ></button>
                <button
                    class="pager__dot"
                    type="button"
                    aria-pressed="false"
                    aria-label="Alerts as they arrive"
                ></button>
            </div>

            <!-- The deck's cards are cloned from this: the same card as above, filled in by
                 build(). -->
            <template id="alert-template">
                <li class="alert">
                    <lord-icon
                        class="alert__icon"
                        current-color
                        intro="hover-pinch, after=.alert"
                        trigger="hover"
                        target=".alert"
                        aria-hidden="true"
                    ></lord-icon>

                    <div class="alert__body">
                        <p class="alert__title"></p>
                        <p class="alert__message"></p>
                    </div>

                    <button class="alert__close" type="button" aria-label="Dismiss">
                        <lord-icon
                            class="alert__close-icon"
                            current-color
                            src="icons/cross.json"
                            trigger="hover"
                            target=".alert__close"
                            aria-hidden="true"
                        ></lord-icon>
                    </button>
                </li>
            </template>
        </main>
    </body>
</html>

main.ts 113 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';

type Kind = 'info' | 'success' | 'warning' | 'error';

const CONTENT: Record<Kind, { icon: string; title: string; message: string }> = {
    info: {
        icon: 'info-circle',
        title: 'Scheduled maintenance',
        message: 'Online banking will be unavailable Sunday 2–4 AM ET for scheduled maintenance.',
    },
    success: {
        icon: 'check-circle',
        title: 'Transfer complete',
        message: '$1,250.00 was successfully sent to Alex Morgan.',
    },
    warning: {
        icon: 'warning-triangle',
        title: 'Low balance',
        message:
            'Your checking account is below $100. Consider transferring funds to avoid overdraft.',
    },
    error: {
        icon: 'cross-circle',
        title: 'Payment declined',
        message: 'Your card ending in 4242 was declined. Check your details and try again.',
    },
};

/** What the button queues, in order. */
const QUEUE: Kind[] = ['error', 'warning', 'success', 'info'];

const template = document.querySelector<HTMLTemplateElement>('#alert-template')!;
const queue = document.querySelector<HTMLElement>('[data-list="queue"]')!;
const add = document.querySelector<HTMLButtonElement>('[data-add]')!;

/** One alert from the template, for the deck. The gallery's cards are in the markup. */
function build(kind: Kind): HTMLElement {
    const { icon, title, message } = CONTENT[kind];
    const alert = template.content.cloneNode(true) as DocumentFragment;
    const card = alert.querySelector<HTMLElement>('.alert')!;

    card.dataset.kind = kind;
    card.querySelector('.alert__icon')!.setAttribute('src', `icons/${icon}.json`);
    card.querySelector('.alert__title')!.textContent = title;
    card.querySelector('.alert__message')!.textContent = message;

    return card;
}

/** The cards in the deck, not counting one on its way out. */
function standing(): HTMLElement[] {
    return ([...queue.children] as HTMLElement[]).filter(
        (card) => !card.hasAttribute('data-leaving'),
    );
}

/** Writes each card's depth: the newest is 0 and in front, the rest recede behind it. */
function restack(): void {
    const cards = standing();

    cards.forEach((card, at) => {
        card.style.setProperty('--depth', String(cards.length - 1 - at));
        card.style.zIndex = String(at);
    });
}

/** Marks the card as leaving, lets the stylesheet animate it out, then removes it. */
async function dismiss(card: HTMLElement): Promise<void> {
    card.dataset.leaving = '';

    // Restack now, so the deck closes up while the card is still on its way out.
    settle();

    // The leaving transitions only exist once a frame has passed with the attribute set.
    await new Promise(requestAnimationFrame);
    await Promise.allSettled(card.getAnimations().map((leaving) => leaving.finished));

    card.remove();
    settle();
}

/** The first kind not already in the deck, so dismissing one brings that kind back. */
function next(): Kind | undefined {
    const up = new Set(standing().map((card) => card.dataset.kind));
    return QUEUE.find((kind) => !up.has(kind));
}

function enqueue(): void {
    const kind = next();
    if (!kind) return;
    const card = build(kind);

    card.querySelector('.alert__close')!.addEventListener('click', () => void dismiss(card));

    queue.append(card);
    settle();
}

/** After any change: who sits where, and whether there is room for one more. */
function settle(): void {
    restack();
    add.disabled = !next();
}

add.addEventListener('click', enqueue);

pager();
settle();

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 CONTENT = {
    info: {
        icon: 'info-circle',
        title: 'Scheduled maintenance',
        message: 'Online banking will be unavailable Sunday 2–4 AM ET for scheduled maintenance.',
    },
    success: {
        icon: 'check-circle',
        title: 'Transfer complete',
        message: '$1,250.00 was successfully sent to Alex Morgan.',
    },
    warning: {
        icon: 'warning-triangle',
        title: 'Low balance',
        message:
            'Your checking account is below $100. Consider transferring funds to avoid overdraft.',
    },
    error: {
        icon: 'cross-circle',
        title: 'Payment declined',
        message: 'Your card ending in 4242 was declined. Check your details and try again.',
    },
};

/** What the button queues, in order. */
const QUEUE = ['error', 'warning', 'success', 'info'];

const template = document.querySelector('#alert-template');
const queue = document.querySelector('[data-list="queue"]');
const add = document.querySelector('[data-add]');

/** One alert from the template, for the deck. The gallery's cards are in the markup. */
function build(kind) {
    const { icon, title, message } = CONTENT[kind];
    const alert = template.content.cloneNode(true);
    const card = alert.querySelector('.alert');

    card.dataset.kind = kind;
    card.querySelector('.alert__icon').setAttribute('src', `icons/${icon}.json`);
    card.querySelector('.alert__title').textContent = title;
    card.querySelector('.alert__message').textContent = message;

    return card;
}

/** The cards in the deck, not counting one on its way out. */
function standing() {
    return [...queue.children].filter((card) => !card.hasAttribute('data-leaving'));
}

/** Writes each card's depth: the newest is 0 and in front, the rest recede behind it. */
function restack() {
    const cards = standing();

    cards.forEach((card, at) => {
        card.style.setProperty('--depth', String(cards.length - 1 - at));
        card.style.zIndex = String(at);
    });
}

/** Marks the card as leaving, lets the stylesheet animate it out, then removes it. */
async function dismiss(card) {
    card.dataset.leaving = '';

    // Restack now, so the deck closes up while the card is still on its way out.
    settle();

    // The leaving transitions only exist once a frame has passed with the attribute set.
    await new Promise(requestAnimationFrame);
    await Promise.allSettled(card.getAnimations().map((leaving) => leaving.finished));

    card.remove();
    settle();
}

/** The first kind not already in the deck, so dismissing one brings that kind back. */
function next() {
    const up = new Set(standing().map((card) => card.dataset.kind));
    return QUEUE.find((kind) => !up.has(kind));
}

function enqueue() {
    const kind = next();
    if (!kind) return;
    const card = build(kind);

    card.querySelector('.alert__close').addEventListener('click', () => void dismiss(card));

    queue.append(card);
    settle();
}

/** After any change: who sits where, and whether there is room for one more. */
function settle() {
    restack();
    add.disabled = !next();
}

add.addEventListener('click', enqueue);

pager();
settle();

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
	`info-circle`	system-outline-367-info-circle
	`check-circle`	system-outline-24-check-circle (edited by hand)
	`warning-triangle`	system-outline-1140-warning-triangle
	`cross-circle`	system-outline-25-cross-circle (edited by hand)
	`cross`	system-outline-38-cross