diff --git a/internal/control/ui.html b/internal/control/ui.html
index 5c09e35..f7fc80a 100644
--- a/internal/control/ui.html
+++ b/internal/control/ui.html
@@ -127,19 +127,19 @@ button { user-select: none; }
 }
 .led.on-green {
   background: var(--green);
-  box-shadow: 0 0 8px var(--green), 0 0 20px var(--green-glow);
+  box-shadow: 0 0 10px rgba(46, 125, 50, 0.45);
 }
 .led.on-red {
   background: var(--accent);
-  box-shadow: 0 0 8px var(--accent), 0 0 20px var(--accent-glow);
+  box-shadow: 0 0 10px rgba(180, 35, 24, 0.45);
 }
 .led.on-amber {
   background: var(--amber);
-  box-shadow: 0 0 8px var(--amber), 0 0 20px var(--amber-glow);
+  box-shadow: 0 0 10px rgba(178, 106, 0, 0.45);
 }
 .led.on-blue {
   background: var(--blue);
-  box-shadow: 0 0 8px var(--blue), 0 0 20px var(--blue-glow);
+  box-shadow: 0 0 10px rgba(41, 98, 179, 0.45);
 }
 
 .status-text {
@@ -149,16 +149,61 @@ button { user-select: none; }
   letter-spacing: 1.2px;
 }
 
-.layout {
-  display: grid;
-  grid-template-columns: minmax(0, 1.35fr) minmax(310px, .75fr);
+.tab-bar {
+  display: flex;
+  gap: 10px;
+  border-bottom: 1px solid var(--border);
+  padding-bottom: 10px;
+  margin: 0 -24px 18px;
+  flex-wrap: wrap;
+}
+.tab-btn {
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  background: transparent;
+  color: var(--text-dim);
+  font-size: 12px;
+  font-weight: 600;
+  padding: 8px 18px;
+  cursor: pointer;
+  transition: all .16s ease;
+}
+.tab-btn.active {
+  border-color: var(--accent);
+  background: var(--surface);
+  color: var(--accent);
+}
+.tab-btn:focus-visible {
+  outline: 2px solid var(--accent);
+  outline-offset: 2px;
+}
+.tab-panels {
+  display: flex;
+  flex-direction: column;
   gap: 14px;
-  align-items: start;
 }
+.tab-panel {
+  display: none;
+}
+.tab-panel.active {
+  display: block;
+}
+.tab-columns {
+  display: grid;
+  gap: 16px;
+}
+.tab-columns.two {
+  grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.85fr);
+}
+.tab-columns.one {
+  grid-template-columns: 1fr;
+}
+
+
 .stack { display: flex; flex-direction: column; gap: 12px; }
 
 .card {
-  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
+  background: var(--surface);
   border: 1px solid var(--border);
   border-radius: var(--radius);
   box-shadow: var(--shadow);
@@ -166,32 +211,6 @@ button { user-select: none; }
 
 .hero {
   padding: 16px;
-  position: relative;
-  overflow: hidden;
-}
-.hero.tx-live::after {
-  content: '';
-  position: absolute;
-  inset: -40%;
-  background: radial-gradient(circle, rgba(48,209,88,.12), transparent 55%);
-  animation: pulseGlow 2.8s ease-in-out infinite;
-  pointer-events: none;
-}
-.hero.tx-busy::after {
-  content: '';
-  position: absolute;
-  inset: -50%;
-  background: conic-gradient(from 0deg, transparent, rgba(255,159,10,.12), transparent 45%);
-  animation: spinWash 2s linear infinite;
-  pointer-events: none;
-}
-@keyframes pulseGlow {
-  0%, 100% { transform: scale(.95); opacity: .45; }
-  50% { transform: scale(1.05); opacity: .8; }
-}
-@keyframes spinWash {
-  from { transform: rotate(0deg); }
-  to { transform: rotate(360deg); }
 }
 @keyframes blinkSoft {
   0%, 100% { opacity: 1; }
@@ -221,10 +240,10 @@ button { user-select: none; }
 .freq-display {
   font-family: var(--display);
   font-size: 38px;
-  color: var(--green);
-  text-shadow: 0 0 15px var(--green-glow);
-  letter-spacing: 1px;
+  color: var(--text);
+  letter-spacing: 0.6px;
   line-height: 1;
+  font-weight: 600;
 }
 .freq-display .unit {
   font-family: var(--mono);
@@ -925,7 +944,12 @@ input.input-error {
 .toast.warn { background: var(--amber); color: #141414; }
 
 @media (max-width: 980px) {
-  .layout { grid-template-columns: 1fr; }
+  .tab-columns.two {
+    grid-template-columns: 1fr;
+  }
+  .tab-bar {
+    margin: 0 -12px 18px;
+  }
   .tx-bar {
     grid-template-columns: 1fr;
     align-items: stretch;
@@ -939,6 +963,12 @@ input.input-error {
 }
 
 @media (max-width: 640px) {
+  .tab-columns.two {
+    grid-template-columns: 1fr;
+  }
+  .tab-bar {
+    margin: 0 -12px 14px;
+  }
   .app { padding: 12px; }
   .header { flex-direction: column; align-items: stretch; gap: 10px; }
   .header h1 { font-size: 22px; }
@@ -978,8 +1008,18 @@ input.input-error {
     </div>
   </div>
 
-  <div class="layout">
-    <div class="stack">
+
+  <div class="tab-bar">
+    <button class="tab-btn active" data-tab="overview" type="button">Overview</button>
+    <button class="tab-btn" data-tab="control" type="button">Control</button>
+    <button class="tab-btn" data-tab="diagnostics" type="button">Diagnostics</button>
+    <button class="tab-btn" data-tab="activity" type="button">Activity</button>
+  </div>
+
+  <div class="tab-panels">
+    <section class="tab-panel active" data-tab-panel="overview">
+      <div class="tab-columns two">
+        <div class="stack">
       <div class="card hero" id="hero-card">
         <div class="tx-bar">
           <div class="freq-display-wrap">
@@ -1054,6 +1094,30 @@ input.input-error {
         </div>
       </div>
 
+
+        </div>
+        <div class="stack">
+          <div class="card sidebar-card">
+        <div class="sidebar-section">
+          <div class="sidebar-title">System Snapshot</div>
+          <div class="kv">
+            <div class="k">Backend</div><div class="v" id="info-backend">--</div>
+            <div class="k">Frequency</div><div class="v" id="info-freq">--</div>
+            <div class="k">Pre-emphasis</div><div class="v" id="info-preemph">--</div>
+            <div class="k">FM Mod</div><div class="v" id="info-fmmod">--</div>
+            <div class="k">Live Config</div><div class="v" id="info-live">--</div>
+          </div>
+        </div>
+
+
+          </div>
+        </div>
+      </div>
+    </section>
+
+    <section class="tab-panel" data-tab-panel="control">
+      <div class="tab-columns two">
+        <div class="stack">
       <div class="card panel" data-panel-key="frequency">
         <div class="panel-head" data-panel>
           <div class="led on-green" style="width:6px;height:6px"></div>
@@ -1091,6 +1155,7 @@ input.input-error {
         </div>
       </div>
 
+
       <div class="card panel" data-panel-key="switches">
         <div class="panel-head" data-panel>
           <div class="led on-green" style="width:6px;height:6px"></div>
@@ -1136,6 +1201,7 @@ input.input-error {
         </div>
       </div>
 
+
       <div class="card panel" data-panel-key="rds">
         <div class="panel-head" data-panel>
           <div class="led on-amber" style="width:6px;height:6px"></div>
@@ -1173,61 +1239,9 @@ input.input-error {
           </div>
         </div>
       </div>
-    </div>
-
-    <div class="stack">
-      <div class="card sidebar-card">
-        <div class="sidebar-section">
-          <div class="sidebar-title">System Snapshot</div>
-          <div class="kv">
-            <div class="k">Backend</div><div class="v" id="info-backend">--</div>
-            <div class="k">Frequency</div><div class="v" id="info-freq">--</div>
-            <div class="k">Pre-emphasis</div><div class="v" id="info-preemph">--</div>
-            <div class="k">FM Mod</div><div class="v" id="info-fmmod">--</div>
-            <div class="k">Live Config</div><div class="v" id="info-live">--</div>
-          </div>
-        </div>
-
-        <div class="sidebar-section">
-          <div class="sidebar-title">Health</div>
-          <div class="health-line"><div class="name">HTTP</div><div class="val" id="health-http">--</div></div>
-          <div class="health-line"><div class="name">Runtime</div><div class="val" id="health-runtime">--</div></div>
-          <div class="health-line"><div class="name">State Age</div><div class="val" id="health-state-age">--</div></div>
-          <div class="health-line"><div class="name">Runtime Signal</div><div class="val" id="health-indicator">--</div></div>
-          <div class="health-line"><div class="name">Runtime Alert</div><div class="val" id="health-alert">--</div></div>
-          <div class="health-line"><div class="name">Transitions (D/M/F)</div><div class="val" id="health-transitions">--</div></div>
-          <div class="health-line"><div class="name">Fault Count</div><div class="val" id="health-fault-count">--</div></div>
-          <div class="health-line"><div class="name">Last Fault</div><div class="val" id="health-last-fault">--</div></div>
-          <div class="health-line"><div class="name">Audio Buffer</div><div class="val" id="health-audio">--</div></div>
-          <div class="health-line"><div class="name">Buffer Duration</div><div class="val" id="health-buffer-duration">--</div></div>
-          <div class="health-line"><div class="name">High Watermark</div><div class="val" id="health-buffer-highwater">--</div></div>
-          <div class="health-line"><div class="name">Queue Fill</div><div class="val" id="health-queue-fill">--</div></div>
-          <div class="health-line"><div class="name">Underrun Streak</div><div class="val" id="health-underrun-streak">--</div></div>
-          <div class="health-line"><div class="name">Last Update</div><div class="val" id="health-last">--</div></div>
-          <div class="health-trend">
-            <div class="health-trend-label">High Watermark Trend</div>
-            <svg class="spark warn" id="spark-high-watermark" viewBox="0 0 160 34" preserveAspectRatio="none"></svg>
-          </div>
-          <div class="health-trend">
-            <div class="health-trend-label">Queue Fill Trend</div>
-            <svg class="spark good" id="spark-queue-fill" viewBox="0 0 160 34" preserveAspectRatio="none"></svg>
-          </div>
-        </div>
-      </div>
-
 
-        <div class="sidebar-section">
-          <div class="sidebar-title">Control Audit</div>
-          <div class="section-note">Counts of 4xx rejects recorded by the control plane APIs.</div>
-          <div class="kv">
-            <div class="k">Rejects total</div><div class="v" id="audit-total">--</div>
-            <div class="k">405 Method Not Allowed</div><div class="v" id="audit-methodNotAllowed">--</div>
-            <div class="k">415 Unsupported Media Type</div><div class="v" id="audit-unsupportedMediaType">--</div>
-            <div class="k">413 Request Too Large</div><div class="v" id="audit-bodyTooLarge">--</div>
-            <div class="k">400 Unexpected Body</div><div class="v" id="audit-unexpectedBody">--</div>
-          </div>
         </div>
-
+        <div class="stack">
       <div class="card panel" data-panel-key="shortcuts">
         <div class="panel-head" data-panel>
           <h2>Shortcuts</h2>
@@ -1251,6 +1265,7 @@ input.input-error {
         </div>
       </div>
 
+
       <div class="card panel" data-panel-key="danger">
         <div class="panel-head" data-panel>
           <h2>Danger Zone</h2>
@@ -1271,6 +1286,58 @@ input.input-error {
         </div>
       </div>
 
+
+        </div>
+      </div>
+    </section>
+
+    <section class="tab-panel" data-tab-panel="diagnostics">
+      <div class="tab-columns two">
+        <div class="stack">
+          <div class="card sidebar-card">
+        <div class="sidebar-section">
+          <div class="sidebar-title">Health</div>
+          <div class="health-line"><div class="name">HTTP</div><div class="val" id="health-http">--</div></div>
+          <div class="health-line"><div class="name">Runtime</div><div class="val" id="health-runtime">--</div></div>
+          <div class="health-line"><div class="name">State Age</div><div class="val" id="health-state-age">--</div></div>
+          <div class="health-line"><div class="name">Runtime Signal</div><div class="val" id="health-indicator">--</div></div>
+          <div class="health-line"><div class="name">Runtime Alert</div><div class="val" id="health-alert">--</div></div>
+          <div class="health-line"><div class="name">Transitions (D/M/F)</div><div class="val" id="health-transitions">--</div></div>
+          <div class="health-line"><div class="name">Fault Count</div><div class="val" id="health-fault-count">--</div></div>
+          <div class="health-line"><div class="name">Last Fault</div><div class="val" id="health-last-fault">--</div></div>
+          <div class="health-line"><div class="name">Audio Buffer</div><div class="val" id="health-audio">--</div></div>
+          <div class="health-line"><div class="name">Buffer Duration</div><div class="val" id="health-buffer-duration">--</div></div>
+          <div class="health-line"><div class="name">High Watermark</div><div class="val" id="health-buffer-highwater">--</div></div>
+          <div class="health-line"><div class="name">Queue Fill</div><div class="val" id="health-queue-fill">--</div></div>
+          <div class="health-line"><div class="name">Underrun Streak</div><div class="val" id="health-underrun-streak">--</div></div>
+          <div class="health-line"><div class="name">Last Update</div><div class="val" id="health-last">--</div></div>
+          <div class="health-trend">
+            <div class="health-trend-label">High Watermark Trend</div>
+            <svg class="spark warn" id="spark-high-watermark" viewBox="0 0 160 34" preserveAspectRatio="none"></svg>
+          </div>
+          <div class="health-trend">
+            <div class="health-trend-label">Queue Fill Trend</div>
+            <svg class="spark good" id="spark-queue-fill" viewBox="0 0 160 34" preserveAspectRatio="none"></svg>
+          </div>
+        </div>
+          </div>
+          <div class="card sidebar-card">
+        <div class="sidebar-section">
+          <div class="sidebar-title">Control Audit</div>
+          <div class="section-note">Counts of 4xx rejects recorded by the control plane APIs.</div>
+          <div class="kv">
+            <div class="k">Rejects total</div><div class="v" id="audit-total">--</div>
+            <div class="k">405 Method Not Allowed</div><div class="v" id="audit-methodNotAllowed">--</div>
+            <div class="k">415 Unsupported Media Type</div><div class="v" id="audit-unsupportedMediaType">--</div>
+            <div class="k">413 Request Too Large</div><div class="v" id="audit-bodyTooLarge">--</div>
+            <div class="k">400 Unexpected Body</div><div class="v" id="audit-unexpectedBody">--</div>
+          </div>
+        </div>
+
+
+          </div>
+        </div>
+        <div class="stack">
       <div class="card panel" data-panel-key="transition-history">
         <div class="panel-head" data-panel>
           <h2>Transition History</h2>
@@ -1285,6 +1352,7 @@ input.input-error {
         </div>
       </div>
 
+
       <div class="card panel" data-panel-key="fault-history">
         <div class="panel-head" data-panel>
           <h2>Fault History</h2>
@@ -1299,6 +1367,14 @@ input.input-error {
         </div>
       </div>
 
+
+        </div>
+      </div>
+    </section>
+
+    <section class="tab-panel" data-tab-panel="activity">
+      <div class="tab-columns one">
+        <div class="stack">
       <div class="card panel" data-panel-key="log">
         <div class="panel-head" data-panel>
           <h2>Activity Log</h2>
@@ -1312,7 +1388,9 @@ input.input-error {
           <div class="log" id="log"><div class="empty-log">No events yet.</div></div>
         </div>
       </div>
-    </div>
+        </div>
+      </div>
+    </section>
   </div>
 </div>