diff --git a/app/static/app.js b/app/static/app.js
index c368079..df078a6 100644
--- a/app/static/app.js
+++ b/app/static/app.js
@@ -14,6 +14,8 @@ let devices = [];
 let selectedDeviceId = null;
 let selectedDevice = null;
 let saveInFlight = false;
+let activeSectionOpen = true;
+let inactiveSectionOpen = false;
 
 function setStatus(msg) {
   statusText.textContent = msg;
@@ -105,6 +107,21 @@ function compareIpNumeric(a, b) {
   return String(a.ip || '').localeCompare(String(b.ip || ''));
 }
 
+function compareDevices(a, b) {
+  const aName = String(a.hostname || '').trim().toLocaleLowerCase();
+  const bName = String(b.hostname || '').trim().toLocaleLowerCase();
+
+  if (aName && bName) {
+    const byName = aName.localeCompare(bName);
+    if (byName !== 0) return byName;
+    return compareIpNumeric(a, b);
+  }
+
+  if (aName) return -1;
+  if (bName) return 1;
+  return compareIpNumeric(a, b);
+}
+
 function renderDeviceList() {
   deviceListEl.innerHTML = '';
 
@@ -113,20 +130,69 @@ function renderDeviceList() {
     return;
   }
 
-  devices.forEach((d) => {
-    const li = document.createElement('li');
-    li.className = `device-item ${selectedDeviceId === d.id ? 'active' : ''}`;
-    li.innerHTML = `
-      <div>${deviceTitle(d)}</div>
-      <div class="meta">${d.os_name || 'OS unknown'} | ${d.is_active ? 'Active' : 'Missing'}</div>
-    `;
-    li.addEventListener('click', () => {
-      selectedDeviceId = d.id;
+  const activeDevices = devices.filter((device) => device.is_active);
+  const inactiveDevices = devices.filter((device) => !device.is_active);
+
+  deviceListEl.appendChild(createSection('Active Machines', activeDevices, activeSectionOpen, true));
+  deviceListEl.appendChild(createSection('Inactive Machines', inactiveDevices, inactiveSectionOpen, false));
+  attachDeviceListHandlers();
+}
+
+function createSection(title, sectionDevices, isOpen, isActiveSection) {
+  const sectionItem = document.createElement('li');
+  sectionItem.className = 'device-section-item';
+
+  const details = document.createElement('details');
+  details.className = 'device-section';
+  details.dataset.section = isActiveSection ? 'active' : 'inactive';
+  details.open = isOpen;
+
+  const itemsHtml = sectionDevices.length
+    ? sectionDevices.map((device) => `
+        <li class="device-item ${selectedDeviceId === device.id ? 'active' : ''}" data-device-id="${device.id}">
+          <div>${escapeHtml(deviceTitle(device))}</div>
+          <div class="meta">${escapeHtml(device.os_name || 'OS unknown')} | ${device.is_active ? 'Active' : 'Missing'}</div>
+        </li>
+      `).join('')
+    : '<li class="device-empty">No machines in this section.</li>';
+
+  details.innerHTML = `
+    <summary class="device-section-summary">
+      <span>${escapeHtml(title)}</span>
+      <span class="device-section-count">${sectionDevices.length}</span>
+    </summary>
+    <ul class="device-section-list">${itemsHtml}</ul>
+  `;
+
+  sectionItem.appendChild(details);
+  return sectionItem;
+}
+
+function attachDeviceListHandlers() {
+  deviceListEl.querySelectorAll('.device-item[data-device-id]').forEach((item) => {
+    item.addEventListener('click', () => {
+      const deviceId = Number(item.dataset.deviceId);
+      if (!deviceId) return;
+      selectedDeviceId = deviceId;
       renderDeviceList();
-      loadDevice(d.id);
+      loadDevice(deviceId);
     });
-    deviceListEl.appendChild(li);
   });
+
+  const activeSection = deviceListEl.querySelector('.device-section[data-section="active"]');
+  const inactiveSection = deviceListEl.querySelector('.device-section[data-section="inactive"]');
+
+  if (activeSection) {
+    activeSection.addEventListener('toggle', () => {
+      activeSectionOpen = activeSection.open;
+    });
+  }
+
+  if (inactiveSection) {
+    inactiveSection.addEventListener('toggle', () => {
+      inactiveSectionOpen = inactiveSection.open;
+    });
+  }
 }
 
 function renderMachineInfo(d) {
@@ -201,10 +267,7 @@ Headers:\n${headers}
 
 async function loadDevices() {
   devices = await api('/api/devices');
-  devices.sort((a, b) => {
-    if (a.is_active !== b.is_active) return b.is_active - a.is_active;
-    return compareIpNumeric(a, b);
-  });
+  devices.sort(compareDevices);
   renderDeviceList();
 
   if (!selectedDeviceId && devices.length) {
@@ -277,10 +340,7 @@ function resetDeviceEdits() {
 
 function updateDeviceInList(updatedDevice) {
   devices = devices.map((device) => (device.id === updatedDevice.id ? { ...device, ...updatedDevice } : device));
-  devices.sort((a, b) => {
-    if (a.is_active !== b.is_active) return b.is_active - a.is_active;
-    return compareIpNumeric(a, b);
-  });
+  devices.sort(compareDevices);
   renderDeviceList();
 }
 
diff --git a/app/static/styles.css b/app/static/styles.css
index 1980e3c..5956198 100644
--- a/app/static/styles.css
+++ b/app/static/styles.css
@@ -164,6 +164,51 @@ button:disabled {
   overflow: auto;
 }
 
+.device-section-item {
+  list-style: none;
+  margin-bottom: 8px;
+}
+
+.device-section {
+  border: 1px solid var(--border);
+  border-radius: 12px;
+  background: rgba(255,255,255,0.015);
+  overflow: hidden;
+}
+
+.device-section-summary {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 11px 12px;
+  cursor: pointer;
+  font-weight: 600;
+  list-style: none;
+  user-select: none;
+}
+
+.device-section-summary::-webkit-details-marker {
+  display: none;
+}
+
+.device-section-count {
+  min-width: 28px;
+  padding: 2px 8px;
+  border: 1px solid var(--border);
+  border-radius: 999px;
+  background: rgba(255,255,255,0.03);
+  color: var(--muted);
+  font-size: 0.78rem;
+  text-align: center;
+}
+
+.device-section-list {
+  list-style: none;
+  margin: 0;
+  padding: 0 6px 6px;
+  border-top: 1px solid rgba(255,255,255,0.04);
+}
+
 .device-item {
   border: 1px solid transparent;
   border-radius: 10px;
@@ -173,6 +218,16 @@ button:disabled {
   cursor: pointer;
 }
 
+.device-section-list .device-item:first-child {
+  margin-top: 6px;
+}
+
+.device-empty {
+  padding: 12px 10px;
+  color: var(--muted);
+  font-size: 0.84rem;
+}
+
 .device-item:hover { border-color: #33516b; }
 .device-item.active { border-color: var(--accent); background: rgba(93,196,255,0.08); }
 
diff --git a/codex-session.bat b/codex-session.bat
new file mode 100644
index 0000000..631ba06
--- /dev/null
+++ b/codex-session.bat
@@ -0,0 +1 @@
+codex resume 019ccf04-af34-7883-a705-2802dd142306