diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
index e4a6d24..2a68ffc 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
@@ -3118,7 +3118,8 @@ let spectrumPanFrac = 0.5;
 
 // Y-axis level: floor = bottom dB value shown; range = total dB span.
 let spectrumFloor = -115;
-let spectrumRange = 80;
+let spectrumRange = 90;
+const SPECTRUM_HEADROOM_DB = 20;
 const SPECTRUM_SMOOTH_ALPHA = 0.42;
 
 // BW-strip drag state.
@@ -4073,7 +4074,7 @@ if (spectrumCanvas) {
       const noise = sorted[Math.floor(sorted.length * 0.15)];
       const peak  = sorted[sorted.length - 1];
       spectrumFloor = Math.floor(noise / 10) * 10 - 10;
-      spectrumRange = Math.max(60, Math.ceil((peak - spectrumFloor) / 10) * 10 + 10);
+      spectrumRange = Math.max(60, Math.ceil((peak - spectrumFloor) / 10) * 10 + SPECTRUM_HEADROOM_DB);
       if (floorInput) floorInput.value = spectrumFloor;
       scheduleSpectrumDraw();
     });
diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
index 3e4adf9..4f476d4 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
@@ -26,6 +26,7 @@
   --filter-border: #385577;
   --wavelength-fg: #8da3be;
   --spectrum-bg: #0a0f18;
+  --spectrum-plot-height: 160px;
   --jog-wheel-size: 83.2px;
   --header-waterfall-overlap: 0rem;
 }
@@ -488,7 +489,7 @@ small { color: var(--text-muted); }
 #rds-ps-overlay {
   display: none;
   position: absolute;
-  top: calc(var(--header-waterfall-overlap) + 0.7rem);
+  top: 50%;
   left: 50%;
   transform: translate(-50%, -50%);
   z-index: 5;
@@ -609,7 +610,7 @@ small { color: var(--text-muted); }
 }
 #overview-canvas {
   width: 100%;
-  height: calc(clamp(4.2rem, 11vh, 6.25rem) + var(--header-waterfall-overlap));
+  height: var(--spectrum-plot-height);
   display: block;
 }
 .header-left {
@@ -986,7 +987,7 @@ button:focus-visible, input:focus-visible, select:focus-visible {
 #spectrum-canvas {
   display: block;
   width: 100%;
-  height: 160px;
+  height: var(--spectrum-plot-height);
   background: var(--spectrum-bg);
   border-radius: 6px 6px 0 0;
   cursor: crosshair;