diff --git a/src/static/patterns.js b/src/static/patterns.js
index a2df5b0..bd25e53 100644
--- a/src/static/patterns.js
+++ b/src/static/patterns.js
@@ -55,8 +55,8 @@ document.addEventListener('DOMContentLoaded', () => {
 
       if (mode === 'create') {
         if (labelEl) {
-          labelEl.textContent = '';
-          labelEl.style.display = 'none';
+          labelEl.textContent = `${key}:`;
+          labelEl.style.display = '';
         }
         if (inputEl) {
           inputEl.value = '';
@@ -203,6 +203,17 @@ document.addEventListener('DOMContentLoaded', () => {
     });
   }
 
+  /** on/off are implemented in driver firmware (presets.py), not as OTA ``.py`` files. */
+  const FIRMWARE_BUILTIN_PATTERNS = new Set(['on', 'off']);
+
+  const isFirmwareBuiltinPattern = (patternName) => {
+    const id = String(patternName || '')
+      .trim()
+      .replace(/\.py$/i, '')
+      .toLowerCase();
+    return FIRMWARE_BUILTIN_PATTERNS.has(id);
+  };
+
   const sendPatternToDevices = async (patternName) => {
     const response = await fetch(`/patterns/${encodeURIComponent(patternName)}/send`, {
       method: 'POST',
@@ -281,7 +292,9 @@ document.addEventListener('DOMContentLoaded', () => {
     }
 
     try {
-      const response = await fetch(`/patterns/ota/file/${encodeURIComponent(patternName)}.py`, {
+      const raw = String(patternName || '').trim();
+      const fileSegment = /\.py$/i.test(raw) ? raw : `${raw}.py`;
+      const response = await fetch(`/patterns/ota/file/${encodeURIComponent(fileSegment)}`, {
         headers: { Accept: 'text/plain' },
       });
       if (!response.ok) {
@@ -315,39 +328,41 @@ document.addEventListener('DOMContentLoaded', () => {
       const label = document.createElement('span');
       label.textContent = patternName;
 
-      const details = document.createElement('span');
-      const minDelay = data && data.min_delay !== undefined ? data.min_delay : '-';
-      const maxDelay = data && data.max_delay !== undefined ? data.max_delay : '-';
-      details.textContent = `${minDelay}–${maxDelay} ms`;
-      details.style.color = '#aaa';
-      details.style.fontSize = '0.85em';
-
-      const sendBtn = document.createElement('button');
-      sendBtn.className = 'btn btn-primary btn-small';
-      sendBtn.textContent = 'Send';
-      sendBtn.addEventListener('click', async () => {
-        try {
-          await sendPatternToDevices(patternName);
-        } catch (error) {
-          console.error('Send pattern failed:', error);
-          alert(error.message || 'Failed to send pattern.');
-        }
-      });
-
-      const editBtn = document.createElement('button');
-      editBtn.className = 'btn btn-secondary btn-small';
-      editBtn.textContent = 'Edit';
-      editBtn.addEventListener('click', async () => {
-        if (patternEditorModal) {
-          patternEditorModal.classList.add('active');
-        }
-        await loadPatternIntoEditor(patternName, data || {});
-      });
-
       row.appendChild(label);
-      row.appendChild(details);
-      row.appendChild(editBtn);
-      row.appendChild(sendBtn);
+
+      if (isFirmwareBuiltinPattern(patternName)) {
+        const note = document.createElement('span');
+        note.className = 'muted-text';
+        note.style.fontSize = '0.85em';
+        note.textContent = 'Built-in (no OTA module)';
+        row.appendChild(note);
+      } else {
+        const sendBtn = document.createElement('button');
+        sendBtn.className = 'btn btn-primary btn-small';
+        sendBtn.textContent = 'Send';
+        sendBtn.addEventListener('click', async () => {
+          try {
+            await sendPatternToDevices(patternName);
+          } catch (error) {
+            console.error('Send pattern failed:', error);
+            alert(error.message || 'Failed to send pattern.');
+          }
+        });
+
+        const editBtn = document.createElement('button');
+        editBtn.className = 'btn btn-secondary btn-small';
+        editBtn.textContent = 'Edit';
+        editBtn.addEventListener('click', async () => {
+          if (patternEditorModal) {
+            patternEditorModal.classList.add('active');
+          }
+          await loadPatternIntoEditor(patternName, data || {});
+        });
+
+        row.appendChild(editBtn);
+        row.appendChild(sendBtn);
+      }
+
       patternsList.appendChild(row);
     });
   };
diff --git a/src/static/style.css b/src/static/style.css
index 70a3ce6..bc297a0 100644
--- a/src/static/style.css
+++ b/src/static/style.css
@@ -1288,6 +1288,12 @@ body.preset-ui-run .edit-mode-only {
     justify-content: stretch;
 }
 
+#pattern-editor-modal .n-param-group:has(.pattern-n-readable-input) label {
+    flex: 0 0 auto;
+    min-width: 2.25rem;
+    font-weight: 500;
+}
+
 #pattern-editor-modal .pattern-n-readable-input {
     flex: 1 1 auto;
     width: 100%;
diff --git a/src/templates/index.html b/src/templates/index.html
index 468a207..c34cca1 100644
--- a/src/templates/index.html
+++ b/src/templates/index.html
@@ -259,14 +259,6 @@
                 <label for="pattern-create-name" style="min-width: 7rem;">Name</label>
                 <input type="text" id="pattern-create-name" class="preset-name-like" placeholder="e.g. sparkle" pattern="[a-zA-Z_][a-zA-Z0-9_]*" style="flex: 1; min-width: 12rem;" autocomplete="off">
             </div>
-            <div class="profiles-row pattern-editor-meta-row" style="flex-wrap: wrap; gap: 0.5rem; margin-bottom: 0.5rem;">
-                <label for="pattern-create-min-delay" style="min-width: 7rem;">Min delay (ms)</label>
-                <input type="number" id="pattern-create-min-delay" min="0" value="10">
-                <label for="pattern-create-max-delay">Max delay (ms)</label>
-                <input type="number" id="pattern-create-max-delay" min="0" value="10000">
-                <label for="pattern-create-max-colors">Max colours</label>
-                <input type="number" id="pattern-create-max-colors" min="0" value="10">
-            </div>
             <div id="pattern-create-n-section" class="n-params-section" style="margin-bottom: 0.5rem;">
                 <h3 class="muted-text">Readable parameter names</h3>
                 <p id="pattern-create-n-empty" class="muted-text" style="display: none; margin: 0 0 0.5rem 0;">No parameter names are stored for this pattern.</p>
@@ -305,6 +297,14 @@
                     </div>
                 </div>
             </div>
+            <div class="profiles-row pattern-editor-meta-row" style="flex-wrap: wrap; gap: 0.5rem; margin-bottom: 0.5rem;">
+                <label for="pattern-create-min-delay" style="min-width: 7rem;">Min delay (ms)</label>
+                <input type="number" id="pattern-create-min-delay" min="0" value="10">
+                <label for="pattern-create-max-delay">Max delay (ms)</label>
+                <input type="number" id="pattern-create-max-delay" min="0" value="10000">
+                <label for="pattern-create-max-colors">Max colours</label>
+                <input type="number" id="pattern-create-max-colors" min="0" value="10">
+            </div>
             <div class="profiles-row" style="flex-direction: column; align-items: stretch; gap: 0.35rem; margin-bottom: 0.5rem;">
                 <label for="pattern-create-file">Pattern file</label>
                 <input type="file" id="pattern-create-file" accept=".py,text/x-python,.PY">