diff --git a/apps/web/src/cockpit-extras.css b/apps/web/src/cockpit-extras.css
index aa6a44c5..9b8f90ba 100644
--- a/apps/web/src/cockpit-extras.css
+++ b/apps/web/src/cockpit-extras.css
@@ -644,9 +644,11 @@
 }
 
 .workspace-card-right-control-spacer {
-  width: 38px;
+  /* Reserve the full absolute-control lane: right offset plus the widest
+   * current rightControl set (two 18px buttons with a 2px gap). */
+  width: 66px;
   height: 18px;
-  flex: 0 0 38px;
+  flex: 0 0 66px;
 }
 
 .workspace-card-collapse {
diff --git a/apps/web/src/workspace-card-layout.test.ts b/apps/web/src/workspace-card-layout.test.ts
new file mode 100644
index 00000000..b2f25dc4
--- /dev/null
+++ b/apps/web/src/workspace-card-layout.test.ts
@@ -0,0 +1,43 @@
+import fs from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { describe, expect, it } from "vitest";
+
+const HERE = path.dirname(fileURLToPath(import.meta.url));
+
+function readCss(): string {
+  return fs.readFileSync(path.join(HERE, "cockpit-extras.css"), "utf8");
+}
+
+function declarationBlock(css: string, selector: string): string {
+  const escaped = selector.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+  const match = css.match(new RegExp(`${escaped}\\s*\\{([^}]*)\\}`, "m"));
+  if (!match?.[1]) throw new Error(`Missing CSS block for ${selector}`);
+  return match[1];
+}
+
+function pxDeclaration(block: string, property: string): number {
+  const escaped = property.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+  const match = block.match(new RegExp(`${escaped}\\s*:\\s*(\\d+(?:\\.\\d+)?)px\\b`));
+  if (!match?.[1]) throw new Error(`Missing px declaration for ${property}`);
+  return Number(match[1]);
+}
+
+describe("workspace-card control lane", () => {
+  it("keeps PR diff totals clear of the structured workspace action buttons", () => {
+    const css = readCss();
+    const controlBlock = declarationBlock(css, ".workspace-card-right-control");
+    const spacerBlock = declarationBlock(css, ".workspace-card-right-control-spacer");
+    const buttonBlock = declarationBlock(css, ".workspace-card-collapse");
+
+    const rightOffset = pxDeclaration(controlBlock, "right");
+    const controlGap = pxDeclaration(controlBlock, "gap");
+    const buttonWidth = pxDeclaration(buttonBlock, "width");
+    const spacerWidth = pxDeclaration(spacerBlock, "width");
+
+    const maxVisibleControls = 2;
+    const requiredLaneWidth = rightOffset + buttonWidth * maxVisibleControls + controlGap * (maxVisibleControls - 1);
+
+    expect(spacerWidth).toBeGreaterThanOrEqual(requiredLaneWidth);
+  });
+});