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

:root {
  --page: #eef2f7;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #5b6678;
  --line: #e2e8f0;
  --ring: #b8c2d0;
  --accent: #2563eb;
  --done: #16a34a;
  --fail: #dc2626;
  --fail-text: #b91c1c;
  --code: #eef2f7;
  --focus: #2563eb;
}

body {
  font-family: system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  margin: 0;
  background: var(--page);
  color: var(--text);
}

.page {
  display: grid;
  grid-template-columns: minmax(0, 560px);
  justify-content: center;
  align-content: center;
  min-height: 100vh;
  padding: 24px 16px;
}

.agent {
  padding: 24px;
  border-radius: 18px;
  background: var(--card);
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.06), 0 12px 32px -12px rgba(15, 23, 42, 0.18);
}

.agent-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.agent-label {
  margin: 0 0 4px;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--muted);
}

.agent-title {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.4;
}

.agent-state {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
  padding: 4px 10px;
  border-radius: 999px;
  background: #f1f5f9;
  color: #475569;
  font-size: 0.8125rem;
  font-weight: 600;
}

.agent-state[data-state="running"] {
  background: #dbeafe;
  color: #1d4ed8;
}

.agent-state[data-state="running"]::before {
  content: "";
  width: 10px;
  height: 10px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.agent-state[data-state="done"] {
  background: #dcfce7;
  color: #166534;
}

.agent-state[data-state="failed"] {
  background: #fee2e2;
  color: #b91c1c;
}

.agent-progress {
  margin: 20px 0 8px;
}

.bar {
  height: 6px;
  overflow: hidden;
  border-radius: 3px;
  background: var(--line);
}

.bar-fill {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--accent);
  transition: width 0.4s ease;
}

.agent-meta {
  display: flex;
  justify-content: space-between;
  margin: 8px 0 0;
  font-size: 0.8125rem;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

.steps {
  display: grid;
  gap: 14px;
  margin: 20px 0;
  padding: 0;
  list-style: none;
}

.step {
  position: relative;
  display: grid;
  grid-template-columns: 22px minmax(0, 1fr) auto;
  gap: 14px;
}

.step:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 28px;
  bottom: -10px;
  left: 10px;
  width: 2px;
  border-radius: 1px;
  background: var(--line);
}

.step[data-state="done"]:not(:last-child)::after {
  background: var(--done);
}

.step-icon {
  position: relative;
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  margin-top: 1px;
  border: 2px solid var(--ring);
  border-radius: 50%;
}

.step[data-state="running"] .step-icon {
  border-color: var(--line);
  border-top-color: var(--accent);
  animation: spin 0.8s linear infinite;
}

.step[data-state="done"] .step-icon {
  border-color: var(--done);
  background: var(--done);
}

.step[data-state="done"] .step-icon::after {
  content: "";
  width: 5px;
  height: 9px;
  margin-top: -2px;
  border: solid #ffffff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.step[data-state="failed"] .step-icon {
  border-color: var(--fail);
  background: var(--fail);
}

.step[data-state="failed"] .step-icon::before,
.step[data-state="failed"] .step-icon::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 2px;
  border-radius: 1px;
  background: #ffffff;
  transform: rotate(45deg);
}

.step[data-state="failed"] .step-icon::after {
  transform: rotate(-45deg);
}

.step[data-state="stopped"] .step-icon::after {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--ring);
}

.step-title {
  margin: 0;
  font-weight: 600;
  line-height: 1.4;
}

.step[data-state="pending"] .step-title {
  color: var(--muted);
  font-weight: 500;
}

.step-body {
  overflow-wrap: anywhere;
}

.step-detail {
  margin: 4px 0 0;
  font-size: 0.875rem;
  color: var(--muted);
}

.step-detail code {
  padding: 1px 6px;
  border-radius: 5px;
  background: var(--code);
  color: var(--text);
  font-family: ui-monospace, Consolas, monospace;
  font-size: 0.8125rem;
}

.step-result {
  margin: 6px 0 0;
  font-size: 0.875rem;
}

.step-result:empty {
  display: none;
}

.step[data-state="failed"] .step-result {
  color: var(--fail-text);
}

.step-time {
  font-size: 0.8125rem;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
  line-height: 1.6;
}

.step-retry {
  margin-top: 10px;
}

.agent-foot {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.btn {
  min-height: 38px;
  padding: 7px 16px;
  border: 1px solid var(--ring);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  font: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
}

.btn:hover:not(:disabled) {
  background: var(--code);
}

.btn-primary {
  border-color: var(--text);
  background: var(--text);
  color: var(--card);
}

.btn-primary:hover:not(:disabled) {
  background: var(--muted);
  border-color: var(--muted);
}

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

.btn:disabled {
  opacity: 0.45;
  cursor: default;
}

.btn[hidden] {
  display: none;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (max-width: 420px) {
  .agent {
    padding: 20px 16px;
  }

  .agent-head {
    flex-direction: column;
    gap: 10px;
  }
}

@media (pointer: coarse) {
  .btn {
    min-height: 44px;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --page: #0b1120;
    --card: #151e30;
    --text: #e2e8f0;
    --muted: #a3afc2;
    --line: #2a3548;
    --ring: #56627a;
    --accent: #60a5fa;
    --done: #22c55e;
    --fail: #ef4444;
    --fail-text: #fca5a5;
    --code: #1e293b;
    --focus: #60a5fa;
  }

  .agent-state {
    background: #1e293b;
    color: #cbd5e1;
  }

  .agent-state[data-state="running"] {
    background: #172554;
    color: #93c5fd;
  }

  .agent-state[data-state="done"] {
    background: #052e16;
    color: #86efac;
  }

  .agent-state[data-state="failed"] {
    background: #450a0a;
    color: #fca5a5;
  }

  .step[data-state="done"] .step-icon::after {
    border-color: #0b1120;
  }

  .step[data-state="failed"] .step-icon::before,
  .step[data-state="failed"] .step-icon::after {
    background: #0b1120;
  }
}

@media (forced-colors: active) {
  .step-icon {
    border-color: CanvasText;
  }

  .step[data-state="running"] .step-icon {
    border-color: GrayText;
    border-top-color: Highlight;
  }

  .step[data-state="done"] .step-icon,
  .step[data-state="failed"] .step-icon {
    forced-color-adjust: none;
    border-color: CanvasText;
    background: CanvasText;
  }

  .step[data-state="done"] .step-icon::after {
    forced-color-adjust: none;
    border-color: Canvas;
  }

  .step[data-state="failed"] .step-icon::before,
  .step[data-state="failed"] .step-icon::after {
    forced-color-adjust: none;
    background: Canvas;
  }

  .step[data-state="stopped"] .step-icon::after {
    forced-color-adjust: none;
    background: CanvasText;
  }

  .bar {
    border: 1px solid CanvasText;
  }

  .bar-fill {
    forced-color-adjust: none;
    background: Highlight;
  }
}

@media (prefers-reduced-motion: reduce) {
  .step[data-state="running"] .step-icon,
  .agent-state[data-state="running"]::before {
    animation-duration: 2.4s;
  }

  .bar-fill {
    transition: none;
  }
}

const steps = [
  { title: "Open the pricing page", tool: "fetch_page", input: "/pricing", result: "Page loaded", ms: 1100 },
  { title: "Collect the links", tool: "extract_links", input: "main content", result: "Found 24 links", ms: 1300 },
  { title: "Check each link", tool: "check_links", input: "24 URLs", result: "22 work, 2 return 404", ms: 1900, failOnce: "3 requests timed out" },
  { title: "Write the summary", tool: "write_summary", input: "link results", result: "Summary ready", ms: 1400 }
];

const stateLabels = { pending: "Pending", running: "Running", done: "Done", failed: "Failed", stopped: "Stopped" };

const list = document.getElementById("steps");
const agentState = document.getElementById("agent-state");
const bar = document.getElementById("bar");
const barFill = document.getElementById("bar-fill");
const countEl = document.getElementById("agent-count");
const timeEl = document.getElementById("agent-time");
const stopBtn = document.getElementById("stop");
const restartBtn = document.getElementById("restart");
const status = document.getElementById("status");

let run = 0;
let current = -1;
let running = false;
let attempts = [];
let spent = 0;
let segmentStart = 0;
let stepStart = 0;
let clockTimer = null;
let controller = null;

function el(tag, className, text) {
  const node = document.createElement(tag);
  if (className) node.className = className;
  if (text) node.textContent = text;
  return node;
}

// Build one list item per step from the data above
const items = steps.map(function(step, i) {
  const li = el("li", "step");
  const icon = el("span", "step-icon");
  const body = el("div", "step-body");
  const state = el("span", "sr-only");
  const title = el("p", "step-title", step.title);
  const detail = el("p", "step-detail");
  const result = el("p", "step-result");
  const retry = el("button", "btn step-retry", "Retry step");
  const time = el("span", "step-time");
  icon.setAttribute("aria-hidden", "true");
  detail.append(el("code", "", step.tool), " " + step.input);
  retry.type = "button";
  retry.addEventListener("click", function() {
    runFrom(i);
    stopBtn.focus();
  });
  title.prepend(state);
  body.append(title, detail, result, retry);
  li.append(icon, body, time);
  list.append(li);
  return { li: li, state: state, result: result, retry: retry, time: time };
});

function seconds(ms) {
  return (ms / 1000).toFixed(1) + " s";
}

function wait(ms) {
  return new Promise(function(resolve) {
    setTimeout(resolve, ms);
  });
}

function setStep(i, state, text) {
  const item = items[i];
  item.li.dataset.state = state;
  item.state.textContent = stateLabels[state] + ": ";
  item.result.textContent = text || "";
  item.retry.hidden = state !== "failed";
  if (state === "running") {
    item.li.setAttribute("aria-current", "step");
  } else {
    item.li.removeAttribute("aria-current");
  }
}

function setAgent(state, label) {
  const focused = document.activeElement;
  agentState.dataset.state = state;
  agentState.textContent = label;
  stopBtn.disabled = state !== "running";
  restartBtn.disabled = state === "running";
  // Keep focus on a button that still works
  if (focused === stopBtn && stopBtn.disabled) {
    const retry = list.querySelector(".step[data-state='failed'] .step-retry");
    (retry || restartBtn).focus();
  } else if (focused === restartBtn && restartBtn.disabled) {
    stopBtn.focus();
  }
}

function updateProgress() {
  const done = items.filter(function(item) {
    return item.li.dataset.state === "done";
  }).length;
  const text = done + " of " + steps.length + " steps done";
  bar.setAttribute("aria-valuemax", String(steps.length));
  bar.setAttribute("aria-valuenow", String(done));
  bar.setAttribute("aria-valuetext", text);
  barFill.style.width = (done / steps.length) * 100 + "%";
  countEl.textContent = text;
}

function tick() {
  const now = performance.now();
  timeEl.textContent = seconds(spent + now - segmentStart);
  if (current >= 0) items[current].time.textContent = seconds(now - stepStart);
}

function startClock() {
  segmentStart = performance.now();
  clockTimer = setInterval(tick, 100);
}

function stopClock() {
  clearInterval(clockTimer);
  tick();
  spent += performance.now() - segmentStart;
}

// Replace with a real tool call, passing signal to fetch
function runStep(step, i, signal) {
  attempts[i] = (attempts[i] || 0) + 1;
  return wait(step.ms).then(function() {
    return !(step.failOnce && attempts[i] === 1);
  });
}

async function runFrom(start) {
  const id = ++run;
  controller = new AbortController();
  running = true;
  setAgent("running", "Running");
  startClock();
  for (let i = start; i < steps.length; i++) {
    current = i;
    stepStart = performance.now();
    setStep(i, "running");
    status.textContent = "Step " + (i + 1) + " of " + steps.length + ": " + steps[i].title;
    let ok = false;
    let reason = steps[i].failOnce || "The step did not finish";
    try {
      ok = await runStep(steps[i], i, controller.signal);
    } catch (err) {
      if (err && err.message) reason = err.message;
      else if (typeof err === "string" && err) reason = err;
    }
    if (id !== run) return;
    if (!ok) {
      stopClock();
      running = false;
      setStep(i, "failed", reason);
      setAgent("failed", "Failed");
      status.textContent = "Step " + (i + 1) + " failed: " + reason;
      return;
    }
    tick();
    setStep(i, "done", steps[i].result);
    updateProgress();
  }
  current = -1;
  stopClock();
  running = false;
  setAgent("done", "Done");
  status.textContent = "Task done in " + timeEl.textContent;
}

function stop() {
  if (!running) return;
  run++;
  controller.abort();
  stopClock();
  running = false;
  setStep(current, "stopped", "Stopped before it finished");
  current = -1;
  setAgent("stopped", "Stopped");
  status.textContent = "Task stopped";
}

function restart() {
  run++;
  clearInterval(clockTimer);
  attempts = [];
  spent = 0;
  current = -1;
  items.forEach(function(item, i) {
    setStep(i, "pending");
    item.time.textContent = "";
  });
  updateProgress();
  timeEl.textContent = seconds(0);
  runFrom(0);
}

stopBtn.addEventListener("click", stop);
restartBtn.addEventListener("click", restart);

items.forEach(function(item, i) {
  setStep(i, "pending");
});
updateProgress();
setTimeout(restart, 400);