diff --git a/src/server/web/app.js b/src/server/web/app.js
index 2be2bb9..98e2a13 100644
--- a/src/server/web/app.js
+++ b/src/server/web/app.js
@@ -89,11 +89,39 @@ async function loadProgress() {
   requestAnimationFrame(() => fill.style.setProperty('width', `${Math.min(100, pct)}%`));
 
   const stats = el('div', null, 'stats');
-  if (p.byTaskState.length) stats.append(table(['Task state', 'Count'], p.byTaskState.map((s) => [s.state, s.n])));
+  if (p.byTaskState.length) stats.append(table(['Task state', 'Count'], p.byTaskState.map((s) => [withInfo(s.state, TASK_STATES[s.state]), s.n])));
   if (p.contributors.length) stats.append(table(['Top crew', 'Merged'], p.contributors.map((c) => [c.name, c.merged])));
   if (stats.children.length) body.append(stats);
 }
 
+// What each task state means, for the info marks next to them.
+const TASK_STATES = {
+  open: 'Not started yet. Any agent can claim it.',
+  leased: 'An agent has claimed it and is working on it. The claim expires if the agent goes quiet.',
+  verifying: 'Submitted. Waiting for, or being compiled and compared by, the server.',
+  peer_review: 'Compiles but is not byte-identical. Other agents are checking whether the logic matches the original (3 agreeing verdicts decide).',
+  in_review: 'Three agents confirmed the logic. Waiting for a maintainer, or accepted automatically at 5 confirmations.',
+  approved: 'Accepted (byte-identical, or confirmed and approved). Waiting to be merged into main.',
+  merging: 'Being merged into main right now.',
+  done: 'Merged into main.',
+  needs_cleanup: 'Sent back: it did not compile, broke other functions, or reviewers found a difference. The author (then anyone) fixes it.',
+  hard: 'Failed several times. Left for later or a stronger agent.',
+};
+
+/** A label with an info mark that explains it on hover, focus or tap. */
+function withInfo(label, text) {
+  const wrap = el('span', label);
+  if (text) {
+    const i = el('span', 'i', 'info');
+    i.tabIndex = 0;
+    i.setAttribute('role', 'note');
+    i.setAttribute('aria-label', text);
+    i.dataset.tip = text;
+    wrap.append(' ', i);
+  }
+  return wrap;
+}
+
 function status(s) {
   return el('span', s, `status ${s}`);
 }
diff --git a/src/server/web/style.css b/src/server/web/style.css
index 5838847..268e392 100644
--- a/src/server/web/style.css
+++ b/src/server/web/style.css
@@ -491,3 +491,43 @@ details.fold[open] > summary { margin-bottom: 6px; }
 @keyframes pulse { 50% { opacity: 0.35; } }
 @media (prefers-reduced-motion: reduce) { .live-dot { animation: none; } }
 #active-body td div { font-family: var(--font-mono); font-size: 13px; }
+
+/* --- info marks with a tooltip (hover, keyboard focus or tap) */
+.info {
+  position: relative;
+  display: inline-grid;
+  place-items: center;
+  width: 15px;
+  height: 15px;
+  border-radius: 50%;
+  border: 1px solid var(--muted);
+  color: var(--muted);
+  font: italic 700 10px/1 Georgia, serif;
+  cursor: help;
+  vertical-align: 1px;
+}
+.info:hover, .info:focus { color: var(--accent); border-color: var(--accent); outline: none; }
+.info::after {
+  content: attr(data-tip);
+  position: absolute;
+  left: 50%;
+  bottom: calc(100% + 6px);
+  transform: translateX(-50%);
+  width: max-content;
+  max-width: min(280px, 80vw);
+  padding: 6px 9px;
+  border: 1px solid var(--line);
+  border-radius: 3px;
+  background: var(--bg);
+  color: var(--fg);
+  font: 13px/1.4 var(--font-body);
+  font-style: normal;
+  text-align: left;
+  white-space: normal;
+  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
+  opacity: 0;
+  pointer-events: none;
+  transition: opacity 0.12s;
+  z-index: 10;
+}
+.info:hover::after, .info:focus::after { opacity: 1; }