# Agent progress

> A coding agent at work: it reads, searches, thinks, writes and reviews, each step in the colour of its kind of work.

A card that follows a coding agent through a task. The header says what it is doing now, in the colour of that kind of work, over a progress line; the steps tick off below, and a panel shows the work as it happens: a file read line by line, a search and its results, thoughts pinned one by one, text typed in, a review’s fixes. The footer counts tokens, cost and time, with Pause, Stop and Run again.

A React component by Bruno Delorence: https://brunodelorence.com/components/agent-progress. MIT License, Copyright (c) 2026 Bruno Delorence.

Category: Feedback.

## Anatomy

1. **Status**: What the agent is doing now, beside its name, in that kind of work’s colour. The whole card turns to the colour together.
2. **Progress line**: A progress bar of the steps done, uncovered by a clip as each one ends.
3. **Step**: One line of the plan: a tick once done, a spinner while in progress, a ring to come.
4. **Detail panel**: The work of the step in progress, coming in piece by piece. Its height eases from step to step in 440 ms.
5. **Tools**: The tools the agent can use; the one the step works in is lit.
6. **Model picker**: A native select under a quiet label, so it opens the platform’s own menu.
7. **Meter**: Tokens spent, their cost and the time, in tabular figures so they don’t jump as they count.
8. **Controls**: Run, then Pause or Resume and a stop button while a run is on, then Run again.

## When to use

- An agent working through a task of a few known steps, where the reader waits for it and wants to see where it is.
- Work that takes seconds to minutes: long enough to need a sign of life, short enough to watch.
- When the work itself is worth showing as it happens: the file read, the search, the code typed, the change made.
- When tokens, cost and time matter to the reader, and they may want to pause or stop the run.

## When not to use

- A wait of a second or two. A spinner or a busy button says enough.
- Open-ended work with no plan up front. Use a streaming log or a chat transcript instead.
- Background jobs nobody watches. Use a notification or a status in a list when they are done.
- Many runs at once. Use a table of jobs with a status column, and open this card for one of them.

## Installation

Install it with the shadcn CLI, into components/agent-progress of any React project:

```sh
npx shadcn@latest add https://brunodelorence.com/r/agent-progress.json
```

Or copy all the source files below into one folder of your project. Either way it needs React 19 and a bundler with CSS Modules (Next.js, Vite).

It has a dark colour scheme. Its colours are CSS light-dark() pairs, kept inside @supports so that builds which rewrite light-dark() for older browsers leave them alone: it follows your page’s color-scheme (light unless the page sets one) or its colorScheme prop, with nothing to configure. Browsers without light-dark() show it light.

## Usage

```tsx
'use client';

import { AgentProgress } from './agent-progress';
import { STEPS } from './run';

export function AgentPanel() {
  // Waits for the reader's Run; reports each finished run.
  return (
    <AgentProgress
      agent="Coding Agent"
      task="Ship dark mode toggle"
      steps={STEPS}
      onComplete={({ tokens, ms }) => console.log(`${tokens} tokens in ${ms / 1000} s`)}
      autoplay={false}
    />
  );
}
```

## States

- **Ready**: Before a run: grey, the steps all to come, Run filled.
- **Reading files**: Violet. The file’s lines come in one by one as it reads.
- **Searching**: Blue. The query types in, then the results arrive.
- **Thinking**: Orange. Thoughts appear in turn; the last is the decision and dims the others.
- **Writing**: Green. The text types in behind a caret.
- **Reviewing**: Pink. Each change strikes the old words out and adds the new.
- **Paused**: The clock stops where it was; the status goes quiet and Resume takes over.
- **Complete**: Every step ticked, the panel sums the run up, and Run again starts over.

## How it works

- The run is a clock. Everything on the card is worked out from the time the run has been going: the step in progress, how far into it, the tokens spent, and how much of the step’s work has come in (lines read, characters typed, results found).
- An animation frame loop moves the clock only while a run plays on screen in a visible tab. It redraws the card only when something it shows changes: a character, a result, a tenth of a thousand tokens, a second.
- Each kind of work sets one colour, --accent. The icon, the status, the progress line, the ticks and the tinted pieces pick it up with a transition, so the whole card turns together from violet to blue, orange, green and red.
- When the step changes, the panel’s height eases from the old content’s height to the new one’s with the Web Animations API, while the new step’s pieces come in one by one.
- It is built for a phone’s GPU. The progress line, reading lines, results and notes come in as clip-path wipes, the tick draws its stroke, and labels fade their colour. Only the bobbing icon and the spinner need layers of their own, and only while the clock runs.
- Every colour is a light-dark() token on the root, the five kinds’ colours included; the script only points --accent at the step’s kind (var(--read) and so on), so the kinds, their tints and the whole card follow the page’s color-scheme, or the colorScheme prop. At night the kinds are lighter, their ticks turn dark, and Run turns light.

## API reference

- **agent** (`string`, default `'Coding Agent'`): The agent’s name, in the header.
- **task** (`string`, default `'Ship dark mode toggle'`): The task it works on, over the steps.
- **steps** (`readonly AgentStep[]`, default `STEPS`): The run. Each step has a kind (read, search, think, write, review), a label, a duration in ms, the tokens it spends, the tool it lights, and its detail: a file and its lines, a query and results, notes, text, or a diff.
- **doneTitle** (`string`, default `'Dark mode shipped'`): What the card says once the run is done.
- **tools** (`readonly string[]`, default `TOOLS`): The tools along the footer; a step lights the one it works in.
- **models** (`readonly string[]`, default `MODELS`): The models in the picker; the first is picked at first.
- **defaultState** (`AgentProgressState`): Opens the card at a moment of a run, with no demo: status ('idle', 'running', 'paused' or 'complete'), elapsed ms, held (a running clock drawn still until a button is pressed) and the model picked.
- **onComplete** (`(run: { tokens: number; ms: number }) => void`): Called when a run is done, with the tokens it spent and how long it took.
- **onStatusChange** (`(status: AgentProgressStatus) => void`): Called when the reader or the demo starts, pauses, resumes or stops a run, or it ends, with the new status.
- **autoplay** (`boolean`, default `true`): While on screen and untouched, starts a run on its own, and another a few seconds after each one ends. A run the reader paused or stopped is left alone.
- **colorScheme** (`'light' | 'dark' | 'system'`): Its colours: light, dark, or the reader’s system setting. Without it the component follows the page’s color-scheme, which is light unless the page sets one.
- **className** (`string`): Extra class for the root, the card’s stage.

## Accessibility

- The steps are an ordered list, each prefixed for screen readers with “Done”, “In progress” or “To do”. The progress line is a progressbar (“2 of 5 steps done”).
- A run the reader starts, pauses or resumes is announced politely, a step at a time (“Searching web: Search open-source examples. Step 2 of 5.”), then at the end with its totals. Tokens and the timer are never announced, and the demo’s own runs stay silent.
- Run, Pause, Resume and Run again are one button whose name follows the run, so focus stays put. “Stop the run” is a separate button, and focus returns to the main button when it goes. The model picker is a native select.
- Under reduced motion the demo never starts. A run the reader starts shows each step whole, without typing, growing lines or easing.

## Source

### agent-progress/agent-progress.tsx

```tsx
// Copyright (c) 2026 Bruno Delorence. MIT License.

'use client';

import {
  useEffect,
  useLayoutEffect,
  useRef,
  useState,
  type CSSProperties,
  type ReactNode,
  type RefObject,
} from 'react';
import {
  CheckIcon,
  ChevronIcon,
  CloseIcon,
  DoneIcon,
  FileIcon,
  PauseIcon,
  PlayIcon,
  RerunIcon,
  SearchIcon,
  SpinnerIcon,
} from './icons';
import {
  KINDS,
  MODELS,
  STEPS,
  TOOLS,
  formatCost,
  formatTime,
  formatTokens,
  frameAt,
  lengthOf,
  revealOf,
  searchReveal,
  spokenTime,
  type AgentStep,
  type DiffPart,
} from './run';
import { useAutoplay } from './use-autoplay';
import styles from './agent-progress.module.css';

/*
 * Agent progress: a card that follows a coding agent through a task. Its header names what the
 * agent is doing now, in that kind of work's colour, over a progress line; the steps tick off
 * below; a panel shows the work itself (the file read, the search, the thoughts, the code typed,
 * the review); and the footer counts tokens, cost and time, with Pause, Stop and Run again.
 *
 * - The run is a clock. Everything on the card is worked out from the time it has been going
 *   (run.ts): the step in progress, how far into it, the tokens spent, how much of the step's
 *   detail has come in. An animation frame loop moves the clock, only while a run plays on screen
 *   in a visible tab, and the card redraws only when something it shows has changed.
 * - Each kind of work sets one colour (--accent) that the icon, the status, the progress line,
 *   the ticks and the tinted pieces take, with a transition, so the whole card turns together.
 * - The panel's height eases from one step to the next (the Web Animations API, from the height
 *   it had to the one its new content needs). The lines, results and thoughts of a step come in
 *   one by one, on transforms and opacity: small pieces, so that on a phone the layers they need
 *   while they move stay light.
 * - The reader's runs are announced, a step at a time, in a polite live region; the tokens are
 *   not. With reduced motion, the steps change without the typing, the growing and the easing.
 * - While on screen and untouched, the demo starts a run on its own, and another once it is done.
 * - Its colours, the kinds' included, are light-dark() pairs in the stylesheet: it follows the
 *   page's color-scheme, or the one the colorScheme prop sets. No colour is computed here.
 * - defaultState opens it ready, at a moment of a run (running, held or not, or paused) or done,
 *   with no demo: for documentation and tests.
 */

/** Where a run is: before it, going, paused, or done. */
export type AgentProgressStatus = 'idle' | 'running' | 'paused' | 'complete';
type Status = AgentProgressStatus;

/** Where the card opens (defaultState): for documentation and tests. */
export type AgentProgressState = {
  /** Ready (the default), running, paused or complete. */
  status?: AgentProgressStatus;
  /** How far into the run, in ms, when running or paused. */
  elapsed?: number;
  /** A running card drawn at that moment with its clock still, until a button is pressed. */
  held?: boolean;
  /** The model picked, one of models. */
  model?: string;
};

/** The colour of the card at rest, before a run: a token of the stylesheet, like the kinds'. */
const IDLE_ACCENT = 'var(--idle)';

const reducedMotion = () => window.matchMedia('(prefers-reduced-motion: reduce)').matches;

/** Whether the element is on screen in a visible tab: the run's clock only moves then. */
function useOnScreen(ref: RefObject<HTMLElement | null>) {
  const [onScreen, setOnScreen] = useState(false);
  useEffect(() => {
    const element = ref.current;
    if (!element) return;
    let intersecting = false;
    const update = () => setOnScreen(intersecting && !document.hidden);
    const observer = new IntersectionObserver(([entry]) => {
      intersecting = entry.isIntersecting;
      update();
    });
    observer.observe(element);
    document.addEventListener('visibilitychange', update);
    return () => {
      observer.disconnect();
      document.removeEventListener('visibilitychange', update);
    };
  }, [ref]);
  return onScreen;
}

/** Whether the reader asks for reduced motion, kept up to date. */
function useReducedMotion() {
  const [reduced, setReduced] = useState(false);
  useEffect(() => {
    const query = window.matchMedia('(prefers-reduced-motion: reduce)');
    const update = () => setReduced(query.matches);
    update();
    query.addEventListener('change', update);
    return () => query.removeEventListener('change', update);
  }, []);
  return reduced;
}

export function AgentProgress({
  agent = 'Coding Agent',
  task = 'Ship dark mode toggle',
  steps = STEPS,
  doneTitle = 'Dark mode shipped',
  tools = TOOLS,
  models = MODELS,
  onComplete,
  onStatusChange,
  defaultState,
  autoplay = true,
  colorScheme,
  className = '',
}: {
  /** The agent's name, in the header. */
  agent?: string;
  /** The task it works on, over the steps. */
  task?: string;
  /** The run: its steps, each of a kind (read, search, think, write, review) with its detail. */
  steps?: readonly AgentStep[];
  /** What the card says once the run is done. */
  doneTitle?: string;
  /** The tools along the footer; a step lights the one it works in. */
  tools?: readonly string[];
  /** The models in the picker; the first is picked at first. */
  models?: readonly string[];
  /** Called when a run is done, with the tokens it spent and how long it took, in ms. */
  onComplete?: (run: { tokens: number; ms: number }) => void;
  /** Called when the reader or the demo starts, pauses, resumes or stops a run, or it ends. */
  onStatusChange?: (status: AgentProgressStatus) => void;
  /** Where the card opens, with no demo: for documentation and tests. */
  defaultState?: AgentProgressState;
  /** While on screen and untouched, the card starts a run on its own, and again once done. */
  autoplay?: boolean;
  /** Its colours: light, dark, or 'system' for the reader's setting; unset, it follows the page. */
  colorScheme?: 'light' | 'dark' | 'system';
  className?: string;
}) {
  const { ref: root, playing, take } = useAutoplay<HTMLDivElement>(6000);
  const onScreen = useOnScreen(root);
  const reduced = useReducedMotion();
  const [status, setStatusNow] = useState<Status>(defaultState?.status ?? 'idle');
  const [elapsed, setElapsed] = useState(() =>
    Math.min(Math.max(defaultState?.elapsed ?? 0, 0), lengthOf(steps)),
  );
  /** A defaultState run held still, until a button is pressed. */
  const [held, setHeld] = useState(!!defaultState?.held);
  const [model, setModel] = useState(defaultState?.model ?? models[0] ?? '');
  /** The demo's press on the Run button, just before it starts a run. */
  const [pressed, setPressed] = useState(false);
  const [message, setMessage] = useState('');

  const length = lengthOf(steps);
  const total = frameAt(steps, length).tokens;

  /**
   * The latest of the run, for the clock and the handlers, which run between renders: its time,
   * whether its steps are announced (a run the reader started or took over), whether the reader
   * stopped it (the demo then leaves it alone).
   */
  const live = useRef({ elapsed, announcing: false, stoppedByReader: false });
  const setStatus = (next: Status) => {
    setStatusNow(next);
    onStatusChange?.(next);
  };
  const primary = useRef<HTMLButtonElement>(null);
  const stopButton = useRef<HTMLButtonElement>(null);
  const panel = useRef<HTMLDivElement>(null);
  const panelInner = useRef<HTMLDivElement>(null);
  /** The panel content's height, kept up to date: the height a change of step eases from. */
  const panelHeight = useRef(0);
  const announcedStep = useRef(-1);

  /** Repeats are made to differ, so screen readers announce them again. */
  const announce = (text: string) => setMessage((now) => (now === text ? `${text}\u00a0` : text));

  // Where the run stands, all from its time.
  const frame = frameAt(steps, elapsed);
  const index = status === 'idle' ? -1 : status === 'complete' ? steps.length : frame.index;
  const step: AgentStep | null = index >= 0 && index < steps.length ? steps[index] : null;
  const reveal = step ? revealOf(step, reduced ? 1 : frame.progress) : 0;
  const done = status === 'idle' ? 0 : Math.min(index, steps.length);
  const tokens = status === 'idle' ? 0 : status === 'complete' ? total : frame.tokens;
  const clock = status === 'idle' ? 0 : status === 'complete' ? length : elapsed;
  const accent =
    status === 'complete' ? KINDS.done.color : step ? KINDS[step.kind].color : IDLE_ACCENT;
  const stateLabel =
    status === 'idle'
      ? 'Ready'
      : status === 'paused'
        ? 'Paused'
        : status === 'complete'
          ? KINDS.done.status
          : step
            ? KINDS[step.kind].status
            : '';
  const activeTool = status === 'running' || status === 'paused' ? step?.tool : undefined;
  const panelKey = status === 'idle' ? 'idle' : status === 'complete' ? 'done' : `step-${index}`;
  const clockOn = status === 'running' && onScreen && !held;

  // Transitions wait for the first render in the browser: the server's frame shows as it is.
  const [ready, setReady] = useState(false);
  useEffect(() => setReady(true), []);
  // The status line rises in when it changes, not when it first shows.
  const [labelShown, setLabelShown] = useState({ label: stateLabel, changed: false });
  if (labelShown.label !== stateLabel) setLabelShown({ label: stateLabel, changed: true });

  /** What the card shows at `ms`: when this changes, it redraws. */
  const viewAt = (ms: number) => {
    const at = frameAt(steps, ms);
    const now = steps[at.index];
    const shown = now ? revealOf(now, reducedMotion() ? 1 : at.progress) : 0;
    return `${at.index}:${shown}:${Math.floor(at.tokens / 100)}:${Math.floor(ms / 1000)}`;
  };

  const start = (byReader: boolean) => {
    live.current = { elapsed: 0, announcing: byReader, stoppedByReader: false };
    announcedStep.current = -1;
    setElapsed(0);
    setStatus('running');
  };

  const finish = () => {
    live.current.elapsed = length;
    setElapsed(length);
    setStatus('complete');
    // The stop button goes with the run: focus moves to Run again.
    if (document.activeElement === stopButton.current) primary.current?.focus();
    if (live.current.announcing) {
      announce(
        `Complete. ${doneTitle}: ${steps.length} steps, ${formatTokens(total)} tokens, ${spokenTime(length)}.`,
      );
    }
    onComplete?.({ tokens: total, ms: length });
  };

  const pause = () => {
    live.current.announcing = true;
    setStatus('paused');
    announce('Paused.');
  };

  const resume = () => {
    live.current.announcing = true;
    setStatus('running');
    announce('Resumed.');
  };

  const stop = () => {
    setHeld(false);
    live.current = { elapsed: 0, announcing: false, stoppedByReader: true };
    setElapsed(0);
    setStatus('idle');
    primary.current?.focus();
    announce('Run stopped.');
  };

  const onPrimary = () => {
    setHeld(false);
    if (status === 'running') pause();
    else if (status === 'paused') resume();
    else start(true);
  };

  // The handlers of the latest render, for the clock and the demo.
  const actions = useRef({ viewAt, finish, start });
  useLayoutEffect(() => {
    actions.current = { viewAt, finish, start };
  });

  // The clock: an animation frame loop, while a run plays on screen. It redraws the card only
  // when what it shows changes (a character, a result, a tenth of a thousand tokens, a second).
  useEffect(() => {
    if (!clockOn) return;
    let request = 0;
    let last = performance.now();
    let shown = actions.current.viewAt(live.current.elapsed);
    const tick = (now: number) => {
      // A frame's time can come before the one noted when the loop started: never backwards.
      // A long frame (a busy page) moves the run on by a tenth of a second at most.
      const next = Math.min(
        length,
        Math.max(0, live.current.elapsed + Math.min(100, Math.max(0, now - last))),
      );
      last = now;
      live.current.elapsed = next;
      if (next >= length) {
        actions.current.finish();
        return;
      }
      const view = actions.current.viewAt(next);
      if (view !== shown) {
        shown = view;
        setElapsed(next);
      }
      request = requestAnimationFrame(tick);
    };
    request = requestAnimationFrame(tick);
    return () => cancelAnimationFrame(request);
  }, [clockOn, length]);

  // Each step of a run the reader follows is announced as it starts.
  useEffect(() => {
    if (status !== 'running' || !step || !live.current.announcing) return;
    if (announcedStep.current === index) return;
    announcedStep.current = index;
    announce(`${KINDS[step.kind].status}: ${step.label}. Step ${index + 1} of ${steps.length}.`);
  }, [status, step, index, steps.length]);

  // The panel's height follows its content as it grows...
  useEffect(() => {
    const inner = panelInner.current;
    if (!inner) return;
    const observer = new ResizeObserver(([entry]) => {
      panelHeight.current = entry.borderBoxSize?.[0]?.blockSize ?? inner.offsetHeight;
    });
    observer.observe(inner);
    return () => observer.disconnect();
  }, []);

  // ...and, when the step changes, eases from the height it had to the one it needs now.
  useLayoutEffect(() => {
    const box = panel.current;
    const inner = panelInner.current;
    const from = panelHeight.current;
    if (!box || !inner || !from || reducedMotion()) return;
    // Mid-way through an earlier change: from where that one had got to.
    const running = box.getAnimations();
    const start = running.length ? parseFloat(getComputedStyle(box).height) : from;
    running.forEach((animation) => animation.cancel());
    const to = inner.offsetHeight;
    if (Math.abs(start - to) < 1) return;
    box.animate([{ height: `${start}px` }, { height: `${to}px` }], {
      duration: 440,
      easing: 'cubic-bezier(0.32, 0.72, 0, 1)',
    });
  }, [panelKey]);

  // The demo: a run starts on its own after a moment (the Run button dips as if pressed), and
  // another a while after it is done. A run the reader paused or stopped is left alone.
  const demo = autoplay && playing && !defaultState;
  useEffect(() => {
    if (!demo || status === 'running' || status === 'paused') return;
    if (status === 'idle' && live.current.stoppedByReader) return;
    let timer = window.setTimeout(
      () => {
        setPressed(true);
        timer = window.setTimeout(() => {
          setPressed(false);
          actions.current.start(false);
        }, 200);
      },
      status === 'complete' ? 4200 : 900,
    );
    return () => {
      window.clearTimeout(timer);
      setPressed(false);
    };
  }, [demo, status]);

  const running = status === 'running' || status === 'paused';

  return (
    <div
      ref={root}
      className={`${styles.root} ${className}`}
      data-color-scheme={colorScheme}
      data-status={status}
      data-ready={ready || undefined}
      data-live={clockOn || undefined}
      style={{ '--accent': accent } as CSSProperties}
      onPointerDownCapture={take}
      onKeyDownCapture={take}
      onFocusCapture={take}
    >
      <section className={styles.card} data-part="card" aria-label={`${agent}: ${task}`}>
        <div className={styles.head} data-part="header">
          <div className={styles.headRow}>
            <span className={styles.bars} aria-hidden="true">
              <span />
              <span />
              <span />
              <span />
            </span>
            <p className={styles.agent}>{agent}</p>
            <p
              className={styles.state}
              data-part="status"
              data-quiet={status === 'idle' || status === 'paused' || undefined}
            >
              <span key={stateLabel} className={labelShown.changed ? styles.stateLabel : undefined}>
                {stateLabel}
              </span>
              <span className={styles.stateDot} aria-hidden="true" />
            </p>
          </div>
          <div
            className={styles.track}
            data-part="progress"
            role="progressbar"
            aria-label="Task progress"
            aria-valuemin={0}
            aria-valuemax={steps.length}
            aria-valuenow={done}
            aria-valuetext={`${done} of ${steps.length} steps done`}
          >
            <span
              className={styles.fill}
              style={{ '--progress': steps.length ? done / steps.length : 0 } as CSSProperties}
            />
          </div>
        </div>

        <div className={styles.sheet}>
          <div className={styles.plan}>
            <p className={styles.task}>
              {task}
              <span className={styles.count} aria-hidden="true">
                {done}/{steps.length}
              </span>
            </p>
            <ol className={styles.steps} data-part="steps" aria-label="Steps">
              {steps.map((item, i) => {
                const state = i < done ? 'done' : i === index ? 'active' : 'pending';
                return (
                  <li key={i} className={styles.step} data-part="step" data-state={state}>
                    <span className={styles.marker} aria-hidden="true">
                      {state === 'done' && <CheckIcon className={styles.check} />}
                      {state === 'active' && <SpinnerIcon className={styles.spinner} />}
                    </span>
                    <span className={styles.hidden}>
                      {state === 'done'
                        ? 'Done: '
                        : state === 'active'
                          ? 'In progress: '
                          : 'To do: '}
                    </span>
                    {item.label}
                  </li>
                );
              })}
            </ol>
          </div>

          <div ref={panel} className={styles.detail} data-part="detail">
            <div ref={panelInner}>
              {status === 'idle' ? (
                <Summary icon={<PlayIcon />} title="Ready to run" quiet>
                  {steps.length} steps · {model}
                </Summary>
              ) : status === 'complete' ? (
                <Summary icon={<DoneIcon />} title={doneTitle}>
                  {steps.length} steps · {formatTokens(total)} tokens · {formatTime(length)}
                </Summary>
              ) : step ? (
                <Detail key={index} step={step} reveal={reveal} />
              ) : null}
            </div>
          </div>

          <div className={styles.tools} data-part="tools">
            <ul className={styles.toolList} aria-label="Tools">
              {tools.map((tool) => (
                <li
                  key={tool}
                  className={styles.tool}
                  data-part="tool"
                  data-on={tool === activeTool || undefined}
                >
                  {tool}
                  {tool === activeTool && <span className={styles.hidden}> (in use)</span>}
                </li>
              ))}
            </ul>
            <label className={styles.model} data-part="model">
              <span aria-hidden="true">{model}</span>
              <ChevronIcon className={styles.chevron} />
              <select
                className={styles.modelSelect}
                value={model}
                aria-label="Model"
                onChange={(event) => setModel(event.target.value)}
              >
                {models.map((name) => (
                  <option key={name}>{name}</option>
                ))}
              </select>
            </label>
          </div>

          <div className={styles.meterRow}>
            <p className={styles.meter} data-part="meter">
              <span className={styles.meterDot} aria-hidden="true" />
              <span>
                <span className={styles.figure}>{formatTokens(tokens)}</span> tokens
              </span>
              <span className={`${styles.figure} ${styles.cost}`}>{formatCost(tokens)}</span>
              <span className={styles.figure}>{formatTime(clock)}</span>
            </p>
            <div className={styles.controls}>
              <button
                ref={primary}
                type="button"
                className={styles.primary}
                data-part="primary"
                data-variant={running ? 'quiet' : 'solid'}
                data-pressed={pressed || undefined}
                onClick={onPrimary}
              >
                {status === 'running' ? (
                  <PauseIcon className={styles.buttonIcon} />
                ) : status === 'paused' ? (
                  <PlayIcon className={styles.buttonIcon} />
                ) : status === 'complete' ? (
                  <RerunIcon className={styles.buttonIcon} />
                ) : (
                  <PlayIcon className={styles.buttonIcon} />
                )}
                {status === 'running'
                  ? 'Pause'
                  : status === 'paused'
                    ? 'Resume'
                    : status === 'complete'
                      ? 'Run again'
                      : 'Run'}
              </button>
              {running && (
                <button
                  ref={stopButton}
                  type="button"
                  className={styles.stop}
                  data-part="stop"
                  aria-label="Stop the run"
                  onClick={stop}
                >
                  <CloseIcon />
                </button>
              )}
            </div>
          </div>
        </div>
      </section>
      <p className={styles.hidden} role="status">
        {message}
      </p>
    </div>
  );
}

/** The panel at rest: ready to run, or done. */
function Summary({
  icon,
  title,
  quiet = false,
  children,
}: {
  icon: ReactNode;
  title: string;
  quiet?: boolean;
  children: ReactNode;
}) {
  return (
    <div className={styles.summary} data-part="summary" data-quiet={quiet || undefined}>
      <span className={styles.summaryIcon} aria-hidden="true">
        {icon}
      </span>
      <p className={styles.summaryText}>
        <strong>{title}</strong>
        <span>{children}</span>
      </p>
    </div>
  );
}

/** The work of the step in progress, as much of it as has come in (`reveal`, from run.ts). */
function Detail({ step, reveal }: { step: AgentStep; reveal: number }) {
  switch (step.kind) {
    case 'read':
      return (
        <Document file={step.file}>
          <span className={styles.skeleton} aria-hidden="true">
            {step.lines.map((width, i) => (
              <span
                key={i}
                className={styles.line}
                style={{ '--width': width } as CSSProperties}
                data-on={i < reveal || undefined}
              />
            ))}
          </span>
          <span className={styles.hidden}>
            {reveal} of {step.lines.length} sections read
          </span>
        </Document>
      );
    case 'search': {
      const { typed, found } = searchReveal(reveal);
      return (
        <div className={styles.search} data-part="search">
          <p className={styles.query}>
            <SearchIcon className={styles.queryIcon} />
            <span className={styles.hidden}>Search: </span>
            {step.query.slice(0, typed)}
            <span className={styles.caret} aria-hidden="true" />
          </p>
          <ul className={styles.results}>
            {step.results.map((result, i) => (
              <li
                key={i}
                className={styles.result}
                data-on={i < found || undefined}
                aria-hidden={i >= found || undefined}
              >
                <span className={styles.resultTitle}>{result.title}</span>
                <span className={styles.resultSource}>{result.source}</span>
              </li>
            ))}
          </ul>
        </div>
      );
    }
    case 'think': {
      const decided = reveal === step.notes.length;
      return (
        <ul className={styles.notes} data-part="notes">
          {step.notes.map((note, i) => (
            <li
              key={i}
              className={styles.note}
              data-on={i < reveal || undefined}
              data-dim={(decided && i < step.notes.length - 1) || undefined}
              aria-hidden={i >= reveal || undefined}
            >
              {note}
            </li>
          ))}
        </ul>
      );
    }
    case 'write':
      return (
        <Document file={step.file}>
          {step.text.slice(0, reveal)}
          <span className={styles.caret} aria-hidden="true" />
        </Document>
      );
    case 'review': {
      const changes = step.diff.filter((part) => typeof part !== 'string').length;
      let change = 0;
      return (
        <Document file={step.file} note={`${changes} ${changes === 1 ? 'change' : 'changes'}`}>
          {step.diff.map((part, i) =>
            typeof part === 'string' ? part : <Change key={i} part={part} on={change++ < reveal} />,
          )}
        </Document>
      );
    }
  }
}

/** A file the agent works in: its name, and what it reads or writes in it. */
function Document({ file, note, children }: { file: string; note?: string; children: ReactNode }) {
  return (
    <div className={styles.document} data-part="document">
      <span className={styles.fileIcon} aria-hidden="true">
        <FileIcon />
      </span>
      <p className={styles.fileName}>
        {file}
        {note && <span className={styles.fileNote}> · {note}</span>}
      </p>
      <p className={styles.prose}>{children}</p>
    </div>
  );
}

/** A change in review: the old words struck out, the new ones after them, once it is made. */
function Change({ part, on }: { part: Exclude<DiffPart, string>; on: boolean }) {
  return (
    <span className={styles.change} data-on={on || undefined}>
      <del className={styles.removed}>
        {on && <span className={styles.hidden}>removed: </span>}
        {part.removed}
      </del>
      {on && (
        <ins className={styles.added}>
          <span className={styles.hidden}>added: </span>
          {part.added}
        </ins>
      )}
    </span>
  );
}
```

### agent-progress/agent-progress.module.css

```css
/* Agent progress (agent-progress.tsx): a white stage with the card in its middle, or at night a
   near-black one with the card a step lighter. The root's --accent is the colour of the work in
   progress; data-status says where the run is, and data-live is set while its clock moves, which
   is when the icon and the spinner animate.

   Colours are the tokens below, each light-dark(light, dark): the component takes the
   color-scheme it inherits from the page (light unless the page says otherwise), or the one its
   colorScheme prop sets (data-color-scheme). */

.root {
  /* The colour of each kind of work, of a finished run and of the card at rest: the script sets
     --accent to one of them. At night they are lighter, to read on the dark card. */
  --read: #7a5af0;
  --search: #4a5df0;
  --think: #e0782a;
  --write: #2d9467;
  --review: #d93f5d;
  --done: #2d9467;
  --idle: #a1a1aa;
  --accent: var(--idle);
  /* The tick on the accent, the tinted pieces, the reading lines, and the query typed in. */
  --accent-ink: #fff;
  --tint: color-mix(in srgb, var(--accent) 11%, #fff);
  --skeleton: color-mix(in srgb, var(--accent) 20%, #fff);
  --query: color-mix(in srgb, var(--accent) 82%, #000);
  /* The stage, the card's grey frame, and the sheet in it: a step lighter each at night, where
     shadows hardly show. */
  --surface: #fff;
  --surface-2: #f2f2f2;
  --surface-3: #fff;
  /* Text: titles and the step in progress; prose, results, the model and the buttons; the steps to
     come; quiet labels, the chevron and the card at rest. */
  --ink: #18181b;
  --ink-soft: #3f3f46;
  --ink-muted: #6e6e76;
  --ink-faint: #a1a1aa;
  /* The faint greys, each its own by day: the steps done, the count, the file's name, the results'
     sources, the tools, the meter and its figures, the stop button's cross. */
  --ink-done: #b2b2b8;
  --ink-count: #b8b8bd;
  --ink-file: #b0b0b6;
  --ink-source: #b9b9be;
  --ink-tool: #9a9aa1;
  --ink-meter: #b4b4ba;
  --ink-figure: #8b8b93;
  --ink-stop: #71717a;
  /* The spinner, the caret, a step to come's ring, the results' bullets and the meter's dot. */
  --spinner: #2c2c31;
  --caret: #52525b;
  --ring: #dddde1;
  --bullet: #c9c9ce;
  --meter-dot: #d4d4d8;
  /* The lines in the sheet (the meter's fainter), and the progress line's track. */
  --line: #ededef;
  --line-soft: #f3f3f4;
  --track: #e3e3e5;
  /* The quiet buttons and the idle icon's square, their frame, and under the pointer. */
  --fill: #f3f3f4;
  --fill-2: #f4f4f5;
  --fill-edge: rgb(0 0 0 / 0.05);
  --fill-hover: #ebebed;
  /* Run: dark by day, light at night; its label, and under the pointer. */
  --solid: #121214;
  --solid-ink: #fff;
  --solid-hover: #2a2a2e;
  /* Thoughts, and the ones the decision dims: their paper, glow and ink. */
  --note: #fef4d3;
  --note-glow: rgb(253 228 155 / 0.5);
  --note-ink: #5f4a19;
  --note-dim: #fefaea;
  --note-dim-glow: rgb(253 228 155 / 0.22);
  --note-dim-ink: #b3a88c;
  /* A review's changes: the words struck out, and the words added. */
  --removed: #fde8eb;
  --removed-ink: #c2334f;
  --removed-strike: rgb(194 51 79 / 0.6);
  --added: #e2f5ea;
  --added-ink: #1f7a50;
  /* Focus rings. */
  --focus: #0a84ff;
  /* The stage's edge; the card's edge, its near shade and its drop; the sheet's edge and shade. */
  --edge: rgb(0 0 0 / 0.06);
  --card-edge: rgb(0 0 0 / 0.075);
  --shadow-near: rgb(0 0 0 / 0.04);
  --shadow: rgb(0 0 0 / 0.16);
  --sheet-edge: rgb(0 0 0 / 0.04);
  --sheet-shadow: rgb(0 0 0 / 0.03);
  --ease: cubic-bezier(0.32, 0.72, 0, 1);
  --mono: ui-monospace, 'SF Mono', SFMono-Regular, Menlo, Consolas, monospace;
  position: relative;
  display: grid;
  place-items: center;
  box-sizing: border-box;
  min-height: 616px;
  padding: 30px 16px;
  container-type: inline-size;
  border-radius: 18px;
  background: var(--surface);
  box-shadow: inset 0 0 0 1px var(--edge);
  color: var(--ink);
  font:
    400 12px/1.4 -apple-system,
    BlinkMacSystemFont,
    'SF Pro Text',
    Inter,
    'Segoe UI',
    sans-serif;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}
@supports (color: light-dark(#fff, #000)) {
  .root {
    --read: light-dark(#7a5af0, #a995ff);
    --search: light-dark(#4a5df0, #8d9cff);
    --think: light-dark(#e0782a, #f39a54);
    --write: light-dark(#2d9467, #45c08a);
    --review: light-dark(#d93f5d, #f77f96);
    --done: light-dark(#2d9467, #45c08a);
    --idle: light-dark(#a1a1aa, #8e8e96);
    --accent-ink: light-dark(#fff, #18181b);
    --tint: light-dark(
      color-mix(in srgb, var(--accent) 11%, #fff),
      color-mix(in srgb, var(--accent) 16%, #242427)
    );
    --skeleton: light-dark(
      color-mix(in srgb, var(--accent) 20%, #fff),
      color-mix(in srgb, var(--accent) 30%, #242427)
    );
    --query: light-dark(
      color-mix(in srgb, var(--accent) 82%, #000),
      color-mix(in srgb, var(--accent) 82%, #fff)
    );
    --surface: light-dark(#fff, #111113);
    --surface-2: light-dark(#f2f2f2, #1c1c1e);
    --surface-3: light-dark(#fff, #242427);
    --ink: light-dark(#18181b, #f4f4f5);
    --ink-soft: light-dark(#3f3f46, #d4d4d8);
    --ink-muted: light-dark(#6e6e76, #b0b0b8);
    --ink-faint: light-dark(#a1a1aa, #8e8e96);
    --ink-done: light-dark(#b2b2b8, #8a8a92);
    --ink-count: light-dark(#b8b8bd, #8a8a92);
    --ink-file: light-dark(#b0b0b6, #8a8a92);
    --ink-source: light-dark(#b9b9be, #8a8a92);
    --ink-tool: light-dark(#9a9aa1, #98989f);
    --ink-meter: light-dark(#b4b4ba, #8a8a92);
    --ink-figure: light-dark(#8b8b93, #a8a8b0);
    --ink-stop: light-dark(#71717a, #a1a1aa);
    --spinner: light-dark(#2c2c31, #e4e4e7);
    --caret: light-dark(#52525b, #a1a1aa);
    --ring: light-dark(#dddde1, #46464c);
    --bullet: light-dark(#c9c9ce, #5c5c63);
    --meter-dot: light-dark(#d4d4d8, #4e4e55);
    --line: light-dark(#ededef, #303034);
    --line-soft: light-dark(#f3f3f4, #2c2c30);
    --track: light-dark(#e3e3e5, #303034);
    --fill: light-dark(#f3f3f4, #303034);
    --fill-2: light-dark(#f4f4f5, #303034);
    --fill-edge: light-dark(rgb(0 0 0 / 0.05), rgb(255 255 255 / 0.06));
    --fill-hover: light-dark(#ebebed, #3a3a3f);
    --solid: light-dark(#121214, #f4f4f5);
    --solid-ink: light-dark(#fff, #18181b);
    --solid-hover: light-dark(#2a2a2e, #d4d4d8);
    --note: light-dark(#fef4d3, #3a3017);
    --note-glow: light-dark(rgb(253 228 155 / 0.5), rgb(250 204 90 / 0.12));
    --note-ink: light-dark(#5f4a19, #f5dc9c);
    --note-dim: light-dark(#fefaea, #2a261b);
    --note-dim-glow: light-dark(rgb(253 228 155 / 0.22), rgb(250 204 90 / 0.04));
    --note-dim-ink: light-dark(#b3a88c, #9a8f72);
    --removed: light-dark(#fde8eb, #48242c);
    --removed-ink: light-dark(#c2334f, #ff8fa3);
    --removed-strike: light-dark(rgb(194 51 79 / 0.6), rgb(255 143 163 / 0.6));
    --added: light-dark(#e2f5ea, #1e3f2f);
    --added-ink: light-dark(#1f7a50, #74dfaa);
    --focus: light-dark(#0a84ff, #3594ff);
    --edge: light-dark(rgb(0 0 0 / 0.06), rgb(255 255 255 / 0.07));
    --card-edge: light-dark(rgb(0 0 0 / 0.075), rgb(255 255 255 / 0.08));
    --shadow-near: light-dark(rgb(0 0 0 / 0.04), rgb(0 0 0 / 0.3));
    --shadow: light-dark(rgb(0 0 0 / 0.16), rgb(0 0 0 / 0.5));
    --sheet-edge: light-dark(rgb(0 0 0 / 0.04), rgb(255 255 255 / 0.05));
    --sheet-shadow: light-dark(rgb(0 0 0 / 0.03), rgb(0 0 0 / 0.25));
  }
}
/* The colorScheme prop. Without it nothing is set: color-scheme is inherited from the page. */
.root[data-color-scheme='light'] {
  color-scheme: light;
}
.root[data-color-scheme='dark'] {
  color-scheme: dark;
}
.root[data-color-scheme='system'] {
  color-scheme: light dark;
}

/* Before the first render in the browser, nothing transitions: the frame the server drew shows
   as it is, even if the styles arrive after the page is first laid out. */
.root:not([data-ready]) * {
  transition: none !important;
}

/* The card: a grey frame (the header, and a rim around the sheet) and a white sheet; at night a
   dark grey frame and a sheet a step lighter. */
.card {
  width: 100%;
  min-width: 0;
  max-width: 500px;
  box-sizing: border-box;
  padding: 0 8px 8px;
  border-radius: 16px;
  background: var(--surface-2);
  box-shadow:
    0 0 0 1px var(--card-edge),
    0 1px 2px var(--shadow-near),
    0 14px 34px -12px var(--shadow);
}

/* The header: the icon, the agent, what it does now, and the progress line under them. */
.head {
  padding: 20px 12px 9px;
}
.headRow {
  display: flex;
  align-items: center;
  height: 28px;
  padding-left: 4px;
}
.agent {
  margin: 0 0 0 16px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: -0.005em;
  white-space: nowrap;
}
.state {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 0 auto;
  padding-left: 12px;
  font-size: 10.5px;
  font-weight: 500;
  color: var(--accent);
  white-space: nowrap;
  transition: color 0.4s ease;
}
.state[data-quiet] {
  color: var(--ink-faint);
}
.stateLabel {
  animation: ink-in 0.4s ease backwards;
}
.stateDot {
  flex: none;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

/* The icon: four bars that bob while the agent works, in the colour of its work. */
.bars {
  display: flex;
  flex: none;
  align-items: center;
  justify-content: space-between;
  width: 22px;
  height: 18px;
  color: var(--accent);
  transition: color 0.4s ease;
}
.bars span {
  width: 3px;
  height: 100%;
  border-radius: 2px;
  background: currentColor;
  transform: scaleY(var(--rest));
}
.bars span:nth-child(1) {
  --rest: 0.6;
  --bob: 0.9s;
  --lag: -0.2s;
}
.bars span:nth-child(2) {
  --rest: 1;
  --bob: 1.1s;
  --lag: -0.65s;
}
.bars span:nth-child(3) {
  --rest: 0.32;
  --bob: 0.8s;
  --lag: -0.4s;
}
.bars span:nth-child(4) {
  --rest: 0.88;
  --bob: 1.25s;
  --lag: -0.9s;
}
.root[data-live] .bars span {
  animation: bob var(--bob) ease-in-out var(--lag) infinite alternate;
}
@keyframes bob {
  from {
    transform: scaleY(0.25);
  }
  to {
    transform: scaleY(1);
  }
}

/* The progress line: a fixed track, and a fill uncovered along it as steps are done (a clip, not
   a scale, so that it needs no layer of its own). */
.track {
  height: 2px;
  margin-top: 17px;
  overflow: hidden;
  border-radius: 1px;
  background: var(--track);
}
.fill {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--accent);
  clip-path: inset(0 calc(100% - var(--progress) * 100%) 0 0);
  transition:
    clip-path 0.9s var(--ease),
    background-color 0.4s ease;
}

/* The sheet: the steps, the panel, the tools and the meter, one under the other. */
.sheet {
  border-radius: 12px;
  background: var(--surface-3);
  box-shadow:
    0 0 0 1px var(--sheet-edge),
    0 1px 2px var(--sheet-shadow);
}

.plan {
  padding: 18px 12px 16px 13px;
}
.task {
  display: flex;
  align-items: baseline;
  gap: 7px;
  margin: 0;
  font-size: 12px;
  font-weight: 600;
  line-height: 20px;
}
.count {
  font: 400 10.5px/1 var(--mono);
  color: var(--ink-count);
}
.steps {
  margin: 8px 0 0;
  padding: 0 0 0 7px;
  list-style: none;
}
.step {
  display: flex;
  align-items: center;
  gap: 11px;
  height: 31px;
  color: var(--ink-muted);
  white-space: nowrap;
  transition: color 0.3s ease;
}
.step[data-state='active'] {
  font-weight: 500;
  color: var(--ink);
}
.step[data-state='done'] {
  color: var(--ink-done);
}
.marker {
  display: grid;
  flex: none;
  place-items: center;
  width: 15px;
  height: 15px;
  border-radius: 50%;
}
.step[data-state='pending'] .marker {
  box-shadow: inset 0 0 0 1.5px var(--ring);
}
.step[data-state='done'] .marker {
  background: var(--accent);
  color: var(--accent-ink);
  transition: background-color 0.4s ease;
}
.check {
  width: 11px;
  height: 11px;
}
/* The tick draws itself as the step is done. */
.check path {
  stroke-dasharray: 1;
  animation: draw 0.4s var(--ease) 0.08s backwards;
}
.spinner {
  width: 15px;
  height: 15px;
  color: var(--spinner);
}
.root[data-live] .spinner {
  animation: spin 0.75s linear infinite;
}
@keyframes spin {
  to {
    transform: rotate(1turn);
  }
}
@keyframes draw {
  from {
    stroke-dashoffset: 1;
  }
}
/* Text that comes in fades its colour in: a repaint of a few glyphs, with no layer. */
@keyframes ink-in {
  from {
    color: transparent;
  }
}

/* The panel: its height eases from step to step (from the script), and the step's own pieces
   come in one by one. Nothing here fades as a whole: on a phone, layers of that size, made and
   dropped at every step, would weigh more than all the rest of the card. */
.detail {
  overflow: hidden;
  overflow: clip;
  border-top: 1px solid var(--line);
}
/* At rest: ready, or done. */
.summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 21px 13px 21px 14px;
}
.summaryIcon {
  display: grid;
  flex: none;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 7px;
  background: var(--tint);
  color: var(--accent);
}
.summaryIcon svg {
  width: 22px;
  height: 22px;
}
.summary[data-quiet] .summaryIcon {
  background: var(--fill-2);
  color: var(--ink-faint);
}
.summary[data-quiet] .summaryIcon svg {
  width: 12px;
  height: 12px;
}
.summaryText {
  display: grid;
  gap: 2px;
  margin: 0;
}
.summaryText strong {
  font-size: 12.5px;
  font-weight: 600;
  line-height: 16px;
}
.summaryText span {
  font-size: 10.5px;
  line-height: 15px;
  color: var(--ink-faint);
}

/* A file: its icon and name, and what is read or written in it. */
.document {
  display: grid;
  grid-template-columns: 21px minmax(0, 1fr);
  column-gap: 13.5px;
  padding: 19.5px 14px 15px;
}
.fileIcon {
  display: grid;
  grid-row: span 2;
  place-items: center;
  width: 21px;
  height: 21px;
  border-radius: 5px;
  background: var(--tint);
  color: var(--accent);
}
.fileIcon svg {
  width: 12px;
  height: 12px;
}
.fileName {
  margin: 0;
  overflow: hidden;
  font: 400 9.5px/14px var(--mono);
  color: var(--ink-file);
  text-overflow: ellipsis;
  white-space: nowrap;
}
.fileNote {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', Inter, 'Segoe UI', sans-serif;
}
.prose {
  margin: 5.5px 0 0;
  font-size: 12px;
  line-height: 20.75px;
  color: var(--ink-soft);
}

/* Reading: lines that grow in, one after another. */
.skeleton {
  display: grid;
  gap: 8px;
  padding: 6px 0 0;
}
.line {
  display: block;
  width: calc(var(--width) * 100%);
  height: 5px;
  border-radius: 3px;
  background: var(--skeleton);
  clip-path: inset(0 100% 0 0 round 3px);
  transition: clip-path 0.55s var(--ease);
}
.line[data-on] {
  clip-path: inset(0 0 0 0 round 3px);
}
.document:has(.skeleton) {
  padding-bottom: 14px;
}

/* Searching: the query types in, then the results come in. */
.search {
  padding: 20px 13px 14px 12px;
}
.query {
  display: inline-flex;
  align-items: center;
  max-width: 100%;
  box-sizing: border-box;
  height: 24px;
  margin: 0;
  padding: 0 9px 0 8px;
  border-radius: 6px;
  background: var(--tint);
  font: 400 10px/1 var(--mono);
  color: var(--query);
  white-space: pre;
}
.queryIcon {
  flex: none;
  width: 12px;
  height: 12px;
  margin-right: 6px;
}
.results {
  margin: 8px 0 0;
  padding: 0 0 0 2px;
  list-style: none;
}
.result {
  display: flex;
  align-items: baseline;
  gap: 7px;
  height: 23.2px;
  line-height: 23.2px;
  clip-path: inset(0 100% 0 0);
  transition: clip-path 0.55s var(--ease);
}
.result[data-on] {
  clip-path: inset(0 -4px 0 0);
}
.result::before {
  flex: none;
  align-self: center;
  width: 4px;
  height: 4px;
  margin-right: 1px;
  border-radius: 50%;
  background: var(--bullet);
  content: '';
}
.resultTitle {
  flex: none;
  font-size: 11.5px;
  color: var(--ink-soft);
}
.result:first-child .resultTitle {
  font-weight: 600;
  color: var(--ink);
}
.resultSource {
  min-width: 0;
  overflow: hidden;
  font: 400 10px/1 var(--mono);
  color: var(--ink-source);
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Thinking: notes that pop in; the last, the decision, dims the others. */
.notes {
  display: grid;
  justify-items: start;
  gap: 11.5px;
  margin: 0;
  padding: 21px 13px 21px 12.5px;
  list-style: none;
}
.note {
  height: 22px;
  max-width: 100%;
  box-sizing: border-box;
  padding: 0 8px;
  overflow: hidden;
  border-radius: 8px;
  background: var(--note);
  box-shadow: 0 0 6px 1px var(--note-glow);
  font-size: 11.5px;
  line-height: 22px;
  color: var(--note-ink);
  text-overflow: ellipsis;
  white-space: nowrap;
  clip-path: inset(-10px calc(100% + 10px) -10px -10px round 14px);
  transition:
    clip-path 0.5s var(--ease),
    background-color 0.4s ease,
    color 0.4s ease,
    box-shadow 0.4s ease;
}
.note[data-on] {
  clip-path: inset(-10px round 14px);
}
.note[data-dim] {
  background: var(--note-dim);
  box-shadow: 0 0 6px 1px var(--note-dim-glow);
  color: var(--note-dim-ink);
}

/* Writing and reviewing: a caret after the text, and the changes. */
.caret {
  display: inline-block;
  width: 1px;
  height: 1.15em;
  margin-left: 2px;
  vertical-align: -0.2em;
  background: var(--caret);
}
.query .caret {
  height: 12px;
  margin-left: 2px;
  background: color-mix(in srgb, currentColor 70%, var(--surface-3));
}
.change del,
.change ins {
  border-radius: 3px;
  text-decoration: none;
  white-space: nowrap;
  transition:
    background-color 0.3s ease,
    color 0.3s ease;
}
.change[data-on] .removed {
  padding: 0 2px;
  background: var(--removed);
  color: var(--removed-ink);
  text-decoration: line-through;
  text-decoration-color: var(--removed-strike);
}
.added {
  margin-left: 3px;
  padding: 0 2px;
  background: var(--added);
  color: var(--added-ink);
  animation: added 0.35s ease backwards;
}
@keyframes added {
  from {
    background-color: transparent;
    color: transparent;
  }
}

/* The tools, and the model. */
.tools {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  height: 43px;
  padding: 0 12px;
  border-top: 1px solid var(--line);
}
/* On a narrow card the last tools fade out at the edge rather than being cut. */
.toolList {
  display: flex;
  flex: 1;
  gap: 7.5px;
  min-width: 0;
  margin: 0;
  padding: 0;
  overflow: hidden;
  list-style: none;
  mask-image: linear-gradient(to right, #000 calc(100% - 18px), transparent);
}
.tool {
  flex: none;
  height: 21px;
  padding: 0 4px;
  border-radius: 5px;
  font-size: 10.5px;
  font-weight: 500;
  line-height: 21px;
  color: var(--ink-tool);
  transition:
    background-color 0.3s ease,
    color 0.3s ease;
}
.tool[data-on] {
  background: var(--tint);
  color: var(--accent);
}
/* The model: its name and a chevron, under a native select made transparent, so the picker is
   the platform's own and the label takes the width of the name shown. */
.model {
  position: relative;
  display: flex;
  flex: none;
  align-items: center;
  gap: 3px;
  height: 24px;
  padding: 0 0 0 4px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 500;
  color: var(--ink-soft);
  white-space: nowrap;
}
.modelSelect {
  position: absolute;
  inset: 0;
  width: 100%;
  margin: 0;
  border: 0;
  font-size: 16px;
  opacity: 0;
  cursor: pointer;
  appearance: none;
}
.model:has(.modelSelect:focus-visible) {
  outline: 2px solid var(--focus);
  outline-offset: 1px;
}
.chevron {
  width: 12px;
  height: 12px;
  color: var(--ink-faint);
}

/* The meter (tokens, cost, time) and the run's buttons. */
.meterRow {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  height: 46px;
  padding: 0 10px 0 12px;
  border-top: 1px solid var(--line-soft);
}
.meter {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-size: 10.5px;
  color: var(--ink-meter);
  white-space: nowrap;
}
.meterDot {
  width: 4px;
  height: 4px;
  margin: 0 -2px 0 2px;
  border-radius: 50%;
  background: var(--meter-dot);
}
.figure {
  font: 400 11px/1 var(--mono);
  color: var(--ink-figure);
}
.controls {
  display: flex;
  flex: none;
  align-items: center;
  gap: 10px;
}
.primary {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  height: 22px;
  margin: 0;
  padding: 0 9px 0 7px;
  border: 0;
  border-radius: 11px;
  background: var(--fill);
  box-shadow: inset 0 0 0 1px var(--fill-edge);
  color: var(--ink-soft);
  font: inherit;
  font-size: 11px;
  font-weight: 500;
  white-space: nowrap;
  cursor: pointer;
  transition:
    transform 0.2s var(--ease),
    background-color 0.2s ease;
}
.primary[data-variant='solid'] {
  height: 25px;
  padding: 0 9px 0 7px;
  border-radius: 13px;
  background: var(--solid);
  box-shadow: none;
  color: var(--solid-ink);
}
.primary:active,
.primary[data-pressed] {
  transform: scale(0.94);
}
.buttonIcon {
  width: 12px;
  height: 12px;
}
.stop {
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: var(--fill-2);
  color: var(--ink-stop);
  cursor: pointer;
}
.stop svg {
  width: 12px;
  height: 12px;
}
.primary:focus-visible,
.stop:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}
@media (hover: hover) {
  .primary[data-variant='quiet']:hover,
  .stop:hover {
    background: var(--fill-hover);
  }
  .primary[data-variant='solid']:hover {
    background: var(--solid-hover);
  }
}

/* For screen readers only. */
.hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

/* Narrow stages: a little less room around everything. */
@container (max-width: 440px) {
  .card {
    padding: 0 6px 6px;
  }
  .head {
    padding-top: 16px;
  }
  .tools {
    padding-right: 8px;
  }
  .toolList {
    gap: 3px;
  }
  .meter {
    gap: 7px;
  }
}

/* The narrowest: the cost gives way to the buttons. */
@container (max-width: 280px) {
  .meterRow {
    padding: 0 8px 0 10px;
  }
  .meter {
    gap: 6px;
  }
  .cost {
    display: none;
  }
  .controls {
    gap: 6px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .stateLabel,
  .check path,
  .added,
  .root[data-live] .bars span,
  .root[data-live] .spinner {
    animation: none;
  }
  .fill,
  .line,
  .result,
  .note,
  .primary {
    transition: none;
  }
}
```

### agent-progress/run.ts

```tsx
/*
 * The run: what the agent does, step by step, and where it stands at any moment of it. A run is
 * a list of steps, each of a kind (reading, searching, thinking, writing, reviewing) with its
 * colour, its status line and what its detail panel shows. Everything the card draws is worked
 * out from the time the run has been going: which step is in progress, how far into it, how many
 * tokens it has spent, and how much of the step's detail has come in.
 */

/** What a step does. Each kind has its own colour, status line and detail panel. */
export type StepKind = 'read' | 'search' | 'think' | 'write' | 'review';

/** A search hit: a title and where it comes from. */
export type SearchResult = { title: string; source: string };

/** A piece of a reviewed sentence: text that stays, or a change (text removed, text added). */
export type DiffPart = string | { removed: string; added: string };

type StepBase = {
  /** What the step does, as the list shows it. */
  label: string;
  /** How long it takes, in ms. */
  ms: number;
  /** The tokens it spends. */
  tokens: number;
  /** The tool it works in, lit in the footer while it runs. */
  tool?: string;
};

export type AgentStep = StepBase &
  (
    | {
        kind: 'read';
        /** The file it reads. */
        file: string;
        /** The lines that come in as it reads, as shares of the panel's width. */
        lines: readonly number[];
      }
    | { kind: 'search'; query: string; results: readonly SearchResult[] }
    | {
        kind: 'think';
        /** The thoughts, in order; the last one is the decision, and dims the others. */
        notes: readonly string[];
      }
    | { kind: 'write'; file: string; text: string }
    | { kind: 'review'; file: string; diff: readonly DiffPart[] }
  );

/**
 * The status line and colour of each kind, and of a finished run. The colours are tokens of the
 * stylesheet (agent-progress.module.css), each a light and a dark value.
 */
export const KINDS: Record<StepKind | 'done', { status: string; color: string }> = {
  read: { status: 'Reading files', color: 'var(--read)' },
  search: { status: 'Searching web', color: 'var(--search)' },
  think: { status: 'Thinking', color: 'var(--think)' },
  write: { status: 'Writing', color: 'var(--write)' },
  review: { status: 'Reviewing', color: 'var(--review)' },
  done: { status: 'Complete', color: 'var(--done)' },
};

/** The task the demo runs: five steps, fifteen seconds, ten and a half thousand tokens. */
export const STEPS: readonly AgentStep[] = [
  {
    kind: 'read',
    label: 'Read theme tokens',
    ms: 2600,
    tokens: 1800,
    tool: 'Files',
    file: 'tokens.css',
    lines: [0.86, 0.68, 0.94, 0.56, 0.78],
  },
  {
    kind: 'search',
    label: 'Search open-source examples',
    ms: 2800,
    tokens: 2200,
    tool: 'Repo',
    query: 'theme toggle css tokens',
    results: [
      { title: 'tint-switch', source: 'harborlab/tint-switch' },
      { title: 'Token-based dark themes', source: 'paletteguide.dev' },
      { title: 'Night mode, step by step', source: 'quietcss.io' },
    ],
  },
  {
    kind: 'think',
    label: 'Pick a token strategy',
    ms: 3200,
    tokens: 1900,
    notes: [
      'Swap tokens, not stylesheets…',
      'Follow the OS setting first',
      'Remember the reader’s choice',
      'One token set, two palettes',
    ],
  },
  {
    kind: 'write',
    label: 'Implement the toggle',
    ms: 3800,
    tokens: 2900,
    tool: 'Files',
    file: 'theme-toggle.tsx',
    text: 'Both themes share one set of tokens. The OS setting applies first, and the switch remembers the choice.',
  },
  {
    kind: 'review',
    label: 'Fix contrast on hover',
    ms: 2600,
    tokens: 1700,
    tool: 'Files',
    file: 'theme-toggle.css',
    diff: [
      'Hover text goes from ',
      { removed: 'gray-400', added: 'gray-600' },
      ' to pass AA, and the focus ring from ',
      { removed: '1px', added: '2px' },
      ' so it shows on dark.',
    ],
  },
];

/** The tools the agent can work in, along the footer. */
export const TOOLS: readonly string[] = ['Repo', 'Files', 'Design', 'Issues', 'Packages'];

/** The models to pick from; the first is picked at first. */
export const MODELS: readonly string[] = ['Sable 3.2', 'Sable 3.2 Mini', 'Sable 2.8'];

/** What a million tokens cost, in dollars. */
const PRICE_PER_MILLION = 3;

/** How long the whole run takes, in ms. */
export const lengthOf = (steps: readonly AgentStep[]) =>
  steps.reduce((total, step) => total + step.ms, 0);

const clamp01 = (value: number) => Math.min(1, Math.max(0, value));

/**
 * Where a run stands `elapsed` ms in: the index of the step in progress (the number of steps once
 * it is over), how far into that step (0 to 1), and the tokens spent so far.
 */
export function frameAt(steps: readonly AgentStep[], elapsed: number) {
  let start = 0;
  let tokens = 0;
  for (let index = 0; index < steps.length; index += 1) {
    const step = steps[index];
    if (elapsed < start + step.ms) {
      const progress = clamp01((elapsed - start) / step.ms);
      return { index, progress, tokens: tokens + step.tokens * progress };
    }
    start += step.ms;
    tokens += step.tokens;
  }
  return { index: steps.length, progress: 1, tokens };
}

/** When the `i`th of `count` items comes in, as a share of its step: spread over `from` to `to`. */
const at = (i: number, count: number, from: number, to: number) =>
  count > 1 ? from + ((to - from) * i) / (count - 1) : from;

/**
 * How much of a step's detail has come in at `progress` (0 to 1): the lines read, the characters
 * typed, the results found, the thoughts had, the changes made. One number per step, which only
 * grows; the card redraws when it changes.
 */
export function revealOf(step: AgentStep, progress: number) {
  switch (step.kind) {
    case 'read':
      return step.lines.filter((_, i) => progress >= at(i, step.lines.length, 0.1, 0.68)).length;
    case 'search': {
      // The query types in first, then the results come in one by one.
      const typed = Math.round(step.query.length * clamp01((progress - 0.02) / 0.18));
      const found = step.results.filter(
        (_, i) => progress >= at(i, step.results.length, 0.25, 0.6),
      ).length;
      return typed + found * 1000;
    }
    case 'think':
      return step.notes.filter((_, i) => progress >= at(i, step.notes.length, 0.08, 0.72)).length;
    case 'write':
      return Math.round(step.text.length * clamp01((progress - 0.05) / 0.78));
    case 'review': {
      const changes = step.diff.filter((part) => typeof part !== 'string').length;
      return Array.from({ length: changes }, (_, i) => at(i, changes, 0.18, 0.62)).filter(
        (start) => progress >= start,
      ).length;
    }
  }
}

/** The query typed and the results found, out of a search's reveal. */
export const searchReveal = (reveal: number) => ({
  typed: reveal % 1000,
  found: Math.floor(reveal / 1000),
});

/** "820", "2.2k", "10.5k". */
export const formatTokens = (tokens: number) =>
  tokens < 1000 ? String(Math.round(tokens)) : `${(Math.floor(tokens / 100) / 10).toFixed(1)}k`;

/** "$0.007": the cost of `tokens`, to a tenth of a cent. */
export const formatCost = (tokens: number) =>
  `$${(Math.round((Math.floor(tokens) * PRICE_PER_MILLION) / 1000) / 1000).toFixed(3)}`;

/** "0:03". */
export const formatTime = (ms: number) => {
  const seconds = Math.floor(ms / 1000);
  return `${Math.floor(seconds / 60)}:${String(seconds % 60).padStart(2, '0')}`;
};

/** "0 minutes 15 seconds", for screen readers. */
export const spokenTime = (ms: number) => {
  const seconds = Math.floor(ms / 1000);
  const minutes = Math.floor(seconds / 60);
  const rest = seconds % 60;
  const parts = [];
  if (minutes) parts.push(`${minutes} minute${minutes === 1 ? '' : 's'}`);
  parts.push(`${rest} second${rest === 1 ? '' : 's'}`);
  return parts.join(' ');
};
```

### agent-progress/icons.tsx

```tsx
/*
 * The card's small icons, drawn on a 16 × 16 grid in the current colour. All are decorative: the
 * buttons and the steps carry their names in text.
 */

type IconProps = { className?: string };

const svg = {
  viewBox: '0 0 16 16',
  fill: 'none',
  stroke: 'currentColor',
  strokeLinecap: 'round',
  strokeLinejoin: 'round',
  'aria-hidden': true,
} as const;

export function CheckIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={2}>
      <path d="m4.6 8.3 2.3 2.3 4.6-4.9" pathLength={1} />
    </svg>
  );
}

/** The bigger tick of a finished run. */
export function DoneIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.5}>
      <path d="m4 8.4 2.7 2.7 5.3-5.8" />
    </svg>
  );
}

/** An arc that turns while a step is in progress. */
export function SpinnerIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.6}>
      <path d="M8 2a6 6 0 0 1 6 6" />
    </svg>
  );
}

export function SearchIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.7}>
      <circle cx="7" cy="7" r="4.3" />
      <path d="m10.3 10.3 3.2 3.2" />
    </svg>
  );
}

export function FileIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.4}>
      <path d="M4.2 2.2h4.9l2.9 2.9v8.7H4.2z" />
      <path d="M9 2.4v2.9h2.8M6.2 8.4h3.6M6.2 10.9h3.6" />
    </svg>
  );
}

export function PauseIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.9}>
      <path d="M5.6 4v8M10.4 4v8" />
    </svg>
  );
}

export function PlayIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.4} fill="currentColor">
      <path d="M5 3.6v8.8l7.1-4.4z" />
    </svg>
  );
}

export function CloseIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.7}>
      <path d="m4.8 4.8 6.4 6.4M11.2 4.8l-6.4 6.4" />
    </svg>
  );
}

export function RerunIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.6}>
      <path d="M12.7 8a4.7 4.7 0 1 1-1.4-3.3" />
      <path d="M11.9 2.4v2.8H9.1" />
    </svg>
  );
}

export function ChevronIcon({ className }: IconProps) {
  return (
    <svg {...svg} className={className} strokeWidth={1.6}>
      <path d="m4.5 6.3 3.5 3.5 3.5-3.5" />
    </svg>
  );
}
```

### agent-progress/use-autoplay.ts

```tsx
'use client';

import { useCallback, useEffect, useRef, useState } from 'react';

/*
 * When a demo may play on its own: while part of it is on screen and the tab is visible, never
 * under reduced motion, and not while the reader is using it. `take()` hands it to the reader; it
 * takes back over `idle` ms after their last input.
 */
export function useAutoplay<T extends HTMLElement>(idle = 6000) {
  const ref = useRef<T>(null);
  const [visible, setVisible] = useState(false);
  const [reduced, setReduced] = useState(true);
  const [taken, setTaken] = useState(false);
  const timer = useRef(0);

  useEffect(() => {
    const element = ref.current;
    if (!element) return;
    let onScreen = false;
    const update = () => setVisible(onScreen && !document.hidden);
    const observer = new IntersectionObserver(
      ([entry]) => {
        onScreen = entry.isIntersecting;
        update();
      },
      { threshold: 0.3 },
    );
    observer.observe(element);
    document.addEventListener('visibilitychange', update);
    const motion = window.matchMedia('(prefers-reduced-motion: reduce)');
    const readMotion = () => setReduced(motion.matches);
    readMotion();
    motion.addEventListener('change', readMotion);
    return () => {
      observer.disconnect();
      document.removeEventListener('visibilitychange', update);
      motion.removeEventListener('change', readMotion);
    };
  }, []);

  const take = useCallback(() => {
    setTaken(true);
    window.clearTimeout(timer.current);
    timer.current = window.setTimeout(() => setTaken(false), idle);
  }, [idle]);
  useEffect(() => () => window.clearTimeout(timer.current), []);

  return { ref, take, playing: visible && !reduced && !taken };
}
```