diff --git a/apps/desktop/src/features/workspace/PracticeProgress.test.tsx b/apps/desktop/src/features/workspace/PracticeProgress.test.tsx
index 2da2f3855..ee2c12533 100644
--- a/apps/desktop/src/features/workspace/PracticeProgress.test.tsx
+++ b/apps/desktop/src/features/workspace/PracticeProgress.test.tsx
@@ -1,111 +1,149 @@
-import { createEvent, fireEvent, render, screen } from "@testing-library/react";
+import { act, createEvent, fireEvent, render, screen, waitFor } from "@testing-library/react";
 import { describe, expect, it, vi } from "vitest";
 import { PracticeProgress } from "./PracticeProgress";
+import userEvent from "@testing-library/user-event";
 
-// Mock the i18n functions
 vi.mock("../../i18n", () => ({
   createTranslator: () => (key: string) => key,
   detectPreferredLocale: () => "en-US",
 }));
 
 describe("PracticeProgress", () => {
-  it("renders with default progress 0 when no progress is provided", () => {
+  it("renders the minimum boundary with a persistent accessible reason", () => {
     const handleChange = vi.fn();
     render(<PracticeProgress onChange={handleChange} />);
 
     expect(screen.getByText("0%")).toBeTruthy();
-    const decreaseBtn = screen.getByRole("button", { name: "decreasePracticeProgressLabel" }) as HTMLButtonElement;
+    const decreaseBtn = screen.getByRole("button", { name: "decreasePracticeProgressLabel" });
     expect(decreaseBtn).toHaveAttribute("aria-disabled", "true");
+    expect(decreaseBtn).not.toHaveAttribute("title");
+
+    const descriptionId = decreaseBtn.getAttribute("aria-describedby");
+    expect(descriptionId).toBeTruthy();
+    expect(document.getElementById(descriptionId ?? "")).toHaveTextContent("practiceProgressAtMin");
 
     const clickEvent = createEvent.click(decreaseBtn);
     fireEvent(decreaseBtn, clickEvent);
     expect(clickEvent.defaultPrevented).toBe(true);
+    expect(handleChange).not.toHaveBeenCalled();
   });
 
-  it("renders provided progress", () => {
+  it("uses the visible practice-progress label as the slider accessible name", () => {
     const handleChange = vi.fn();
     render(<PracticeProgress progress={50} onChange={handleChange} />);
 
+    expect(screen.getByRole("slider", { name: "practiceProgressLabel" })).toBeInTheDocument();
     expect(screen.getByText("50%")).toBeTruthy();
   });
 
-  it("calls onChange with increased value when increase button is clicked", () => {
+  it("shows the boundary tooltip on keyboard focus and dismisses it with Escape", async () => {
     const handleChange = vi.fn();
-    render(<PracticeProgress progress={50} onChange={handleChange} />);
+    render(<PracticeProgress progress={0} onChange={handleChange} />);
 
-    const increaseBtn = screen.getByRole("button", { name: "increasePracticeProgressLabel" });
-    fireEvent.click(increaseBtn);
-
-    expect(handleChange).toHaveBeenCalledWith(60);
+    const decreaseBtn = screen.getByRole("button", { name: "decreasePracticeProgressLabel" });
+    fireEvent.focus(decreaseBtn);
+
+    expect(
+      await screen.findByText("decreasePracticeProgressLabel: practiceProgressAtMin"),
+    ).toBeInTheDocument();
+
+    fireEvent.keyDown(document, { key: "Escape" });
+    await waitFor(() => {
+      expect(
+        screen.queryByText("decreasePracticeProgressLabel: practiceProgressAtMin"),
+      ).not.toBeInTheDocument();
+    });
   });
 
-  it("calls onChange with decreased value when decrease button is clicked", () => {
+  it("shows the action tooltip after pointer hover", async () => {
     const handleChange = vi.fn();
     render(<PracticeProgress progress={50} onChange={handleChange} />);
 
-    const decreaseBtn = screen.getByRole("button", { name: "decreasePracticeProgressLabel" });
-    fireEvent.click(decreaseBtn);
+    const increaseBtn = screen.getByRole("button", { name: "increasePracticeProgressLabel" });
+    await userEvent.hover(increaseBtn);
 
-    expect(handleChange).toHaveBeenCalledWith(40);
+    expect(await screen.findByText("increasePracticeProgressLabel")).toBeInTheDocument();
   });
 
-  it("does not exceed 100 when increasing", () => {
+  it("changes progress from the increment and decrement controls", () => {
     const handleChange = vi.fn();
-    render(<PracticeProgress progress={95} onChange={handleChange} />);
+    render(<PracticeProgress progress={50} onChange={handleChange} />);
 
-    const increaseBtn = screen.getByRole("button", { name: "increasePracticeProgressLabel" });
-    fireEvent.click(increaseBtn);
+    fireEvent.click(screen.getByRole("button", { name: "increasePracticeProgressLabel" }));
+    expect(handleChange).toHaveBeenLastCalledWith(60);
 
-    expect(handleChange).toHaveBeenCalledWith(100);
+    fireEvent.click(screen.getByRole("button", { name: "decreasePracticeProgressLabel" }));
+    expect(handleChange).toHaveBeenLastCalledWith(40);
   });
 
-  it("does not go below 0 when decreasing", () => {
-    const handleChange = vi.fn();
-    render(<PracticeProgress progress={5} onChange={handleChange} />);
+  it("clamps button changes to the 0-100 range", () => {
+    const handleIncrease = vi.fn();
+    const { rerender } = render(<PracticeProgress progress={95} onChange={handleIncrease} />);
 
-    const decreaseBtn = screen.getByRole("button", { name: "decreasePracticeProgressLabel" });
-    fireEvent.click(decreaseBtn);
+    fireEvent.click(screen.getByRole("button", { name: "increasePracticeProgressLabel" }));
+    expect(handleIncrease).toHaveBeenCalledWith(100);
 
-    expect(handleChange).toHaveBeenCalledWith(0);
+    const handleDecrease = vi.fn();
+    rerender(<PracticeProgress progress={5} onChange={handleDecrease} />);
+    fireEvent.click(screen.getByRole("button", { name: "decreasePracticeProgressLabel" }));
+    expect(handleDecrease).toHaveBeenCalledWith(0);
   });
 
-  it("calls onChange when slider is changed", () => {
+  it("changes progress through the Base UI slider keyboard contract", async () => {
     const handleChange = vi.fn();
     render(<PracticeProgress progress={50} onChange={handleChange} />);
 
-    const slider = screen.getByRole("slider");
-    fireEvent.change(slider, { target: { value: "75" } });
+    const slider = screen.getByRole("slider", { name: "practiceProgressLabel" });
+    await act(async () => {
+      slider.focus();
+      fireEvent.keyDown(slider, { key: "ArrowRight", code: "ArrowRight" });
+    });
 
-    expect(handleChange).toHaveBeenCalledWith(75);
+    expect(handleChange).toHaveBeenCalledWith(51);
   });
 
-  it("keeps focus on interactive controls instead of the progress region", () => {
+  it("keeps 44 CSS px interaction envelopes without making the visible track oversized", () => {
     const handleChange = vi.fn();
-    render(<PracticeProgress progress={50} onChange={handleChange} />);
+    const { container } = render(<PracticeProgress progress={50} onChange={handleChange} />);
 
-    expect(screen.getByRole("region", { name: "practiceProgressRegionLabel" })).not.toHaveAttribute("tabindex");
-    expect(screen.getByRole("slider")).toBeInTheDocument();
+    const decreaseBtn = screen.getByRole("button", { name: "decreasePracticeProgressLabel" });
+    const increaseBtn = screen.getByRole("button", { name: "increasePracticeProgressLabel" });
+    const slider = screen.getByRole("slider", { name: "practiceProgressLabel" });
+    const thumb = slider.parentElement;
+    const control = container.querySelector('[data-slot="slider-control"]');
+    const track = container.querySelector('[data-slot="slider-track"]');
+
+    expect(decreaseBtn).toHaveClass("size-11");
+    expect(increaseBtn).toHaveClass("size-11");
+    expect(control).toHaveClass("h-11", "min-h-11");
+    expect(track).toHaveClass("h-3");
+    expect(track).not.toHaveClass("overflow-hidden");
+    expect(thumb).toHaveClass("after:inset-[-12px]");
   });
 
-  it("ignores invalid slider input gracefully", () => {
+  it("keeps focus on interactive controls instead of the progress region", () => {
     const handleChange = vi.fn();
     render(<PracticeProgress progress={50} onChange={handleChange} />);
 
-    const slider = screen.getByRole("slider");
-    fireEvent.change(slider, { target: { value: "invalid" } });
-
-    expect(handleChange).not.toHaveBeenCalled();
+    expect(screen.getByRole("region", { name: "practiceProgressRegionLabel" })).not.toHaveAttribute("tabindex");
+    expect(screen.getByRole("slider", { name: "practiceProgressLabel" })).toBeInTheDocument();
   });
 
-  it("disables increase button when progress is 100", () => {
+  it("keeps the maximum boundary focusable with a persistent accessible reason", () => {
     const handleChange = vi.fn();
     render(<PracticeProgress progress={100} onChange={handleChange} />);
 
-    const increaseBtn = screen.getByRole("button", { name: "increasePracticeProgressLabel" }) as HTMLButtonElement;
+    const increaseBtn = screen.getByRole("button", { name: "increasePracticeProgressLabel" });
     expect(increaseBtn).toHaveAttribute("aria-disabled", "true");
+    expect(increaseBtn).not.toHaveAttribute("title");
+
+    const descriptionId = increaseBtn.getAttribute("aria-describedby");
+    expect(descriptionId).toBeTruthy();
+    expect(document.getElementById(descriptionId ?? "")).toHaveTextContent("practiceProgressAtMax");
 
     const clickEvent = createEvent.click(increaseBtn);
     fireEvent(increaseBtn, clickEvent);
     expect(clickEvent.defaultPrevented).toBe(true);
+    expect(handleChange).not.toHaveBeenCalled();
   });
 });
diff --git a/apps/desktop/src/features/workspace/PracticeProgress.tsx b/apps/desktop/src/features/workspace/PracticeProgress.tsx
index d10ca94c0..16144494b 100644
--- a/apps/desktop/src/features/workspace/PracticeProgress.tsx
+++ b/apps/desktop/src/features/workspace/PracticeProgress.tsx
@@ -1,16 +1,29 @@
-import { memo, useCallback } from "react";
+import { memo, useCallback, useId } from "react";
 import { Minus, Plus } from "lucide-react";
+import {
+  Slider,
+  SliderControl,
+  SliderIndicator,
+  SliderLabel,
+  SliderThumb,
+  SliderTrack,
+} from "../../components/ui/slider";
 import { createTranslator, detectPreferredLocale } from "../../i18n";
+import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
 
-/** Documented. */
+/** Properties for the rehearsal practice-progress control. */
 interface PracticeProgressProps {
   progress?: number;
   onChange: (newProgress: number) => void;
 }
 
-/** Documented. */
+/** Render the rehearsal practice-progress controls and accessible boundary cues. */
 function PracticeProgressComponent({ progress = 0, onChange }: PracticeProgressProps) {
   const t = createTranslator(detectPreferredLocale());
+  const decreaseLimitDescriptionId = useId();
+  const increaseLimitDescriptionId = useId();
+  const atMinimum = progress <= 0;
+  const atMaximum = progress >= 100;
 
   const handleDecrease = useCallback((e: React.MouseEvent<HTMLButtonElement>) => {
     if (progress <= 0) {
@@ -28,69 +41,91 @@ function PracticeProgressComponent({ progress = 0, onChange }: PracticeProgressP
     onChange(Math.min(100, progress + 10));
   }, [progress, onChange]);
 
-  const handleSliderChange = useCallback((e: React.ChangeEvent<HTMLInputElement>) => {
-    const value = parseInt(e.target.value, 10);
-    if (!Number.isNaN(value)) {
-      onChange(Math.max(0, Math.min(100, value)));
+  const handleSliderChange = useCallback((value: number | readonly number[]) => {
+    const numericValue = Array.isArray(value) ? value[0] : value;
+    if (typeof numericValue !== "number" || !Number.isFinite(numericValue)) {
+      return;
     }
+    onChange(Math.max(0, Math.min(100, numericValue)));
   }, [onChange]);
 
+  const decreaseActionLabel = t("decreasePracticeProgressLabel");
+  const increaseActionLabel = t("increasePracticeProgressLabel");
+  const minimumReason = t("practiceProgressAtMin");
+  const maximumReason = t("practiceProgressAtMax");
+
   return (
     <div
       className="mt-4 rounded-xl border border-indigo-300/20 bg-indigo-300/[0.08] p-4 focus-within:ring-2 focus-within:ring-indigo-300"
       role="region"
       aria-label={t("practiceProgressRegionLabel")}
     >
-      <div className="mb-2 flex items-center justify-between">
-        <label htmlFor="practice-progress-slider" className="text-xs font-black uppercase tracking-[0.24em] text-indigo-200">
-          {t("practiceProgressLabel")}
-        </label>
-        <span className="text-sm font-semibold text-slate-200">{progress}%</span>
-      </div>
+      <Slider
+        min={0}
+        max={100}
+        step={1}
+        value={progress}
+        onValueChange={handleSliderChange}
+        className="block w-full"
+      >
+        <div className="mb-2 flex items-center justify-between">
+          <SliderLabel className="text-xs font-black uppercase tracking-[0.24em] text-indigo-200">
+            {t("practiceProgressLabel")}
+          </SliderLabel>
+          <span className="text-sm font-semibold text-slate-200">{progress}%</span>
+        </div>
 
-      <div className="flex items-center gap-4">
-        <button
-          type="button"
-          onClick={handleDecrease}
-          aria-disabled={progress <= 0 ? "true" : undefined}
-          className="flex size-8 items-center justify-center rounded-full border border-white/10 bg-white/5 text-slate-300 transition-colors hover:bg-white/10 hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-300 aria-disabled:cursor-not-allowed aria-disabled:opacity-50"
-          aria-label={t("decreasePracticeProgressLabel")}
-          title={t("decreasePracticeProgressLabel")}
-        >
-          <Minus className="size-4" aria-hidden="true" />
-        </button>
+        <div className="flex items-center gap-4">
+          <Tooltip>
+            <TooltipTrigger
+              type="button"
+              onClick={handleDecrease}
+              aria-disabled={atMinimum ? "true" : undefined}
+              aria-describedby={atMinimum ? decreaseLimitDescriptionId : undefined}
+              className="flex size-11 items-center justify-center rounded-full border border-white/10 bg-white/5 text-slate-300 transition-colors hover:bg-white/10 hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-300 aria-disabled:cursor-not-allowed aria-disabled:opacity-50"
+              aria-label={decreaseActionLabel}
+            >
+              <Minus className="size-4" aria-hidden="true" />
+            </TooltipTrigger>
+            <TooltipContent>
+              {atMinimum ? `${decreaseActionLabel}: ${minimumReason}` : decreaseActionLabel}
+            </TooltipContent>
+          </Tooltip>
+          {atMinimum ? (
+            <span id={decreaseLimitDescriptionId} className="sr-only">
+              {minimumReason}
+            </span>
+          ) : null}
 
-        <div className="relative h-3 flex-1 overflow-hidden rounded-full bg-slate-900/50 shadow-inner">
-          <div
-            className="absolute left-0 top-0 h-full rounded-full bg-gradient-to-r from-indigo-500 to-cyan-400 transition-all duration-200 ease-out"
-            style={{ width: `${progress}%` }}
-          />
-          <input
-            id="practice-progress-slider"
-            type="range"
-            min="0"
-            max="100"
-            step="1"
-            value={progress}
-            onChange={handleSliderChange}
-            className="absolute inset-0 h-full w-full cursor-pointer opacity-0"
-            aria-valuenow={progress}
-            aria-valuemin={0}
-            aria-valuemax={100}
-          />
-        </div>
+          <SliderControl className="h-11 min-h-11 flex-1">
+            <SliderTrack className="h-3 bg-slate-900/50 shadow-inner">
+              <SliderIndicator className="bg-gradient-to-r from-indigo-500 to-cyan-400 transition-all duration-200 ease-out" />
+              <SliderThumb />
+            </SliderTrack>
+          </SliderControl>
 
-        <button
-          type="button"
-          onClick={handleIncrease}
-          aria-disabled={progress >= 100 ? "true" : undefined}
-          className="flex size-8 items-center justify-center rounded-full border border-white/10 bg-white/5 text-slate-300 transition-colors hover:bg-white/10 hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-300 aria-disabled:cursor-not-allowed aria-disabled:opacity-50"
-          aria-label={t("increasePracticeProgressLabel")}
-          title={t("increasePracticeProgressLabel")}
-        >
-          <Plus className="size-4" aria-hidden="true" />
-        </button>
-      </div>
+          <Tooltip>
+            <TooltipTrigger
+              type="button"
+              onClick={handleIncrease}
+              aria-disabled={atMaximum ? "true" : undefined}
+              aria-describedby={atMaximum ? increaseLimitDescriptionId : undefined}
+              className="flex size-11 items-center justify-center rounded-full border border-white/10 bg-white/5 text-slate-300 transition-colors hover:bg-white/10 hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-300 aria-disabled:cursor-not-allowed aria-disabled:opacity-50"
+              aria-label={increaseActionLabel}
+            >
+              <Plus className="size-4" aria-hidden="true" />
+            </TooltipTrigger>
+            <TooltipContent>
+              {atMaximum ? `${increaseActionLabel}: ${maximumReason}` : increaseActionLabel}
+            </TooltipContent>
+          </Tooltip>
+          {atMaximum ? (
+            <span id={increaseLimitDescriptionId} className="sr-only">
+              {maximumReason}
+            </span>
+          ) : null}
+        </div>
+      </Slider>
     </div>
   );
 }
diff --git a/apps/desktop/src/locales/en/common.json b/apps/desktop/src/locales/en/common.json
index d803a765e..2a3c549d3 100644
--- a/apps/desktop/src/locales/en/common.json
+++ b/apps/desktop/src/locales/en/common.json
@@ -149,6 +149,8 @@
   "practiceProgressLabel": "Practice Progress",
   "decreasePracticeProgressLabel": "Decrease progress",
   "increasePracticeProgressLabel": "Increase progress",
+  "practiceProgressAtMin": "Progress is already at 0%.",
+  "practiceProgressAtMax": "Progress is already at 100%.",
   "workspaceFirstRangeTitle": "Tonight's first range",
   "workspaceFirstRangeCheck": "{roleName} sits {lowestNote}–{highestNote} in {sectionLabel}. Check that span on your instrument before the {sectionLabel}.",
   "workspaceFirstRangeClash": "{roleName} sits {lowestNote}–{highestNote} in {sectionLabel}. Hear that clash on your instrument before the {sectionLabel}.",
diff --git a/apps/desktop/src/locales/ko/common.json b/apps/desktop/src/locales/ko/common.json
index 0f6c6c66d..8f4d98f88 100644
--- a/apps/desktop/src/locales/ko/common.json
+++ b/apps/desktop/src/locales/ko/common.json
@@ -149,6 +149,8 @@
   "practiceProgressLabel": "연습 진척도",
   "decreasePracticeProgressLabel": "진척도 감소",
   "increasePracticeProgressLabel": "진척도 증가",
+  "practiceProgressAtMin": "진척도가 이미 0%입니다.",
+  "practiceProgressAtMax": "진척도가 이미 100%입니다.",
   "workspaceFirstRangeTitle": "오늘 먼저 볼 음역",
   "workspaceFirstRangeCheck": "{sectionLabel}의 {roleName}은 {lowestNote}–{highestNote}입니다. {sectionLabel} 들어가기 전에 그 음역을 악기로 확인해 보세요.",
   "workspaceFirstRangeClash": "{sectionLabel}의 {roleName}은 {lowestNote}–{highestNote}이고 다른 파트와 겹칩니다. {sectionLabel} 들어가기 전에 그 충돌을 악기로 들어 보세요.",