diff --git a/src/ui/leftPanelRail.js b/src/ui/leftPanelRail.js
index 3df30677d..ca11a8149 100644
--- a/src/ui/leftPanelRail.js
+++ b/src/ui/leftPanelRail.js
@@ -59,6 +59,7 @@ export function layoutLeftPanelRail({
     stack.style.removeProperty('--left-stack-safe-top');
     stack.style.removeProperty('--left-stack-safe-bottom');
     stack.style.removeProperty('--left-stack-centered-height');
+    stack.style.removeProperty('--panel-rail-offset');
     stack.classList.remove('layout-exclusive');
     stack.dataset.layoutMode = 'mobile';
     settleSideAccordion({ panels, enabled: false, onCollapse });
@@ -275,6 +276,16 @@ export function layoutLeftPanelRail({
   ) {
     stack.style.setProperty('--left-stack-safe-bottom', bottomValue);
   }
+  // The rail stays where the resting stack puts it; only the panels move.
+  // A theme that pins the stack's top (Cyber) leaves nothing to offset.
+  const topPinned =
+    getComputedStyle(stack)
+      .getPropertyValue?.('--panel-stack-top-pinned')
+      ?.trim() === '1';
+  const railOffset = `${(topPinned ? 0 : safeTop - layoutTop).toFixed(1)}px`;
+  if (stack.style.getPropertyValue('--panel-rail-offset') !== railOffset) {
+    stack.style.setProperty('--panel-rail-offset', railOffset);
+  }
   stack.style.removeProperty('--left-stack-centered-height');
   for (const panel of panels)
     panel.style.removeProperty('--left-panel-allocated-height');
diff --git a/src/ui/panelRails.test.mjs b/src/ui/panelRails.test.mjs
index 5650feb44..801fd02f4 100644
--- a/src/ui/panelRails.test.mjs
+++ b/src/ui/panelRails.test.mjs
@@ -349,6 +349,32 @@ test('right rail aligns to the current left rail and excludes hidden obstacles',
   assert.equal(f.stack.dataset.safeTop, '200.0');
 });
 
+// An opened panel moves the left stack up, but its rail buttons hold still:
+// the right rail lines up with those buttons, not with the moved stack.
+test('right rail aligns to the left rail buttons while the left stack is offset', () => {
+  const f = fixture('right');
+  f.options.leftStack.rect.top = 100;
+  f.options.leftStack.style.setProperty('--panel-rail-offset', '186.7px');
+  f.run();
+  assert.equal(f.stack.dataset.safeTop, '286.7');
+});
+
+test('left rail buttons hold still while a tall panel moves the stack', () => {
+  const f = fixture('left');
+  f.expand(f.first, 900);
+  f.run();
+  assert.equal(f.stack.dataset.layoutMode, 'focus');
+  assert.ok(
+    parseFloat(f.stack.style.getPropertyValue('--panel-rail-offset')) > 0,
+  );
+
+  // A theme that pins the stack's top (Cyber) leaves nothing to offset.
+  f.stack.computed.getPropertyValue = (name) =>
+    name === '--panel-stack-top-pinned' ? ' 1' : '';
+  f.run();
+  assert.equal(f.stack.style.getPropertyValue('--panel-rail-offset'), '0.0px');
+});
+
 // The left rail's `top` animates after the right pass runs, and nothing
 // re-runs it when the transition lands: the right rail must read the end value.
 function animatingLeftRail({ keyframes = true } = {}) {
diff --git a/src/ui/rightPanelRail.js b/src/ui/rightPanelRail.js
index 40a80f3ba..44043fb01 100644
--- a/src/ui/rightPanelRail.js
+++ b/src/ui/rightPanelRail.js
@@ -126,8 +126,11 @@ export function layoutRightPanelRail({
     viewportHeight,
     getComputedStyle,
   );
+  // Align with the left rail's buttons, which hold still while its stack moves.
+  const leftRailOffset =
+    parseFloat(leftStack?.style.getPropertyValue('--panel-rail-offset')) || 0;
   const alignedTop = Number.isFinite(leftStackTop)
-    ? leftStackTop
+    ? leftStackTop + leftRailOffset
     : viewportHeight * 0.26;
   const obstacleRects = [];
 
diff --git a/src/ui/styles/cyber.css b/src/ui/styles/cyber.css
index 122357e97..4f5b4f9f9 100644
--- a/src/ui/styles/cyber.css
+++ b/src/ui/styles/cyber.css
@@ -1654,6 +1654,8 @@
   }
 
   :root[data-ui-theme='cyber'] #left-panel-stack {
+    /* The stack holds still, so its rail needs no offset (leftPanelRail.js). */
+    --panel-stack-top-pinned: 1;
     top: var(--cyber-left-rail-top) !important;
     bottom: calc(2vh + 13rem);
     left: calc(54px + var(--panel-rail-clearance));
diff --git a/src/ui/styles/layers.css b/src/ui/styles/layers.css
index 90915c6b3..3074429ce 100644
--- a/src/ui/styles/layers.css
+++ b/src/ui/styles/layers.css
@@ -245,12 +245,15 @@
 }
 
 /* Panel rails (src/ui/panelNavigation.js). Each rail lives inside its stack,
-   so it shows and hides with the stack, and floats in the screen-edge gutter. */
+   so it shows and hides with the stack, and floats in the screen-edge gutter.
+   The stack's layout offsets it back to its resting top, so it holds still
+   when an opened panel moves the stack. */
 .gev-panel-rail {
   position: absolute;
-  top: 0;
+  top: var(--panel-rail-offset, 0px);
   z-index: 1;
   pointer-events: auto;
+  transition: top var(--transition-fast);
 }
 .gev-panel-rail--left {
   right: calc(100% + 6px);