diff --git a/apps/web/src/appearanceContrast.test.ts b/apps/web/src/appearanceContrast.test.ts
index 3e6c1fad0..4be2f77cc 100644
--- a/apps/web/src/appearanceContrast.test.ts
+++ b/apps/web/src/appearanceContrast.test.ts
@@ -17,17 +17,21 @@ describe("applyAppearanceContrast", () => {
     applyAppearanceContrast(root, 135);
 
     expect(setProperty).toHaveBeenCalledWith("--appearance-contrast-base", "100%");
-    expect(setProperty).toHaveBeenCalledWith("--appearance-contrast-boost", "35%");
+    expect(setProperty).toHaveBeenCalledWith("--appearance-contrast-boost", "21%");
     expect(setProperty).toHaveBeenCalledWith("--appearance-contrast-border-boost", "8.75%");
   });
 
-  it("supports the maximum contrast boost", () => {
+  // The foreground mix stops short of the target on purpose: a full 100% makes
+  // every foreground role resolve to the target itself, so normal, muted and
+  // placeholder text become the same colour at the slider's own maximum.
+  it("keeps the maximum foreground boost short of a full mix", () => {
     const { root, setProperty } = makeRoot();
 
     applyAppearanceContrast(root, 200);
 
     expect(setProperty).toHaveBeenCalledWith("--appearance-contrast-base", "100%");
-    expect(setProperty).toHaveBeenCalledWith("--appearance-contrast-boost", "100%");
+    expect(setProperty).toHaveBeenCalledWith("--appearance-contrast-boost", "60%");
+    expect(setProperty).not.toHaveBeenCalledWith("--appearance-contrast-boost", "100%");
     expect(setProperty).toHaveBeenCalledWith("--appearance-contrast-border-boost", "25%");
   });
 
diff --git a/apps/web/src/appearanceContrast.ts b/apps/web/src/appearanceContrast.ts
index a26dca013..05ed0864d 100644
--- a/apps/web/src/appearanceContrast.ts
+++ b/apps/web/src/appearanceContrast.ts
@@ -1,10 +1,25 @@
 import type { AppearanceContrast } from "@t3tools/contracts/settings";
 
+/**
+ * The boost mixes every foreground role toward one shared target, so a full
+ * 100% resolves them all to exactly that target and the normal/muted/placeholder
+ * hierarchy disappears — an empty composer becomes indistinguishable from a
+ * filled one. Measured in a browser against the real tokens: at contrast 200 an
+ * unscaled boost puts `--contrast-foreground`, `--contrast-muted-foreground`,
+ * `--contrast-placeholder` and `--contrast-icon-muted` all at `oklab(0 0 0)`.
+ *
+ * Capping the mix keeps the top of the range clearly darker than the default
+ * while holding the roles apart. Lightness separation between normal and muted
+ * text: 0.278 at the default, 0.111 here, 0 unscaled.
+ *
+ * Borders are excluded — they carry a single role, so converging on the target
+ * costs no hierarchy, and their own quarter-weight already bounds them.
+ */
+const FOREGROUND_BOOST_RATIO = 0.6;
+
 export function applyAppearanceContrast(root: HTMLElement, contrast: AppearanceContrast): void {
+  const overshoot = Math.max(contrast - 100, 0);
   root.style.setProperty("--appearance-contrast-base", `${Math.min(contrast, 100)}%`);
-  root.style.setProperty("--appearance-contrast-boost", `${Math.max(contrast - 100, 0)}%`);
-  root.style.setProperty(
-    "--appearance-contrast-border-boost",
-    `${Math.max(contrast - 100, 0) / 4}%`,
-  );
+  root.style.setProperty("--appearance-contrast-boost", `${overshoot * FOREGROUND_BOOST_RATIO}%`);
+  root.style.setProperty("--appearance-contrast-border-boost", `${overshoot / 4}%`);
 }