diff --git a/src/css/styles.css b/src/css/styles.css
index 657fee9..22bcebb 100644
--- a/src/css/styles.css
+++ b/src/css/styles.css
@@ -202,6 +202,116 @@ h1.title {
     font-weight: 700;
     color: var(--vault-yellow);
     font-size: 1.4rem;
+    transition: all 0.3s ease;
+}
+
+/* Professional Timer Warning - Polished & Theme-Aware */
+.score-big.timer-critical {
+    color: #ff3333 !important;
+    font-size: 2.2rem !important;
+    font-weight: 800 !important;
+    animation: timerUrgent 1.4s ease-in-out infinite;
+    transition: all 0.3s ease;
+}
+
+/* Light theme adjustment */
+[data-theme="light"] .score-big.timer-critical {
+    color: #cc0000 !important;
+}
+
+@keyframes timerUrgent {
+    0%, 100% {
+        transform: scale(1);
+        text-shadow: 0 0 15px rgba(255, 51, 51, 0.7),
+                     0 0 30px rgba(255, 51, 51, 0.4),
+                     0 2px 6px rgba(0, 0, 0, 0.3);
+    }
+    50% {
+        transform: scale(1.08);
+        text-shadow: 0 0 25px rgba(255, 51, 51, 0.9),
+                     0 0 50px rgba(255, 51, 51, 0.6),
+                     0 3px 8px rgba(0, 0, 0, 0.4);
+    }
+}
+
+/* Light theme timer glow */
+[data-theme="light"] .score-big.timer-critical {
+    text-shadow: 0 0 12px rgba(204, 0, 0, 0.6),
+                 0 0 25px rgba(204, 0, 0, 0.3),
+                 0 2px 4px rgba(0, 0, 0, 0.2);
+}
+
+/* Timer bar - smooth professional pulse */
+.timer-bar-fill.timer-bar-critical {
+    background: linear-gradient(90deg, #ff1a1a, #ff4444) !important;
+    animation: barPulse 1.4s ease-in-out infinite;
+    box-shadow: 0 0 12px rgba(255, 26, 26, 0.6);
+    transition: all 0.3s ease;
+}
+
+/* Light theme bar */
+[data-theme="light"] .timer-bar-fill.timer-bar-critical {
+    background: linear-gradient(90deg, #cc0000, #ff3333) !important;
+    box-shadow: 0 0 10px rgba(204, 0, 0, 0.5);
+}
+
+@keyframes barPulse {
+    0%, 100% {
+        box-shadow: 0 0 12px rgba(255, 26, 26, 0.6);
+    }
+    50% {
+        box-shadow: 0 0 20px rgba(255, 26, 26, 0.8),
+                    0 0 35px rgba(255, 26, 26, 0.4);
+    }
+}
+
+/* Light theme bar pulse */
+[data-theme="light"] .timer-bar-fill.timer-bar-critical {
+    animation: barPulseLight 1.4s ease-in-out infinite;
+}
+
+@keyframes barPulseLight {
+    0%, 100% {
+        box-shadow: 0 0 10px rgba(204, 0, 0, 0.5);
+    }
+    50% {
+        box-shadow: 0 0 18px rgba(204, 0, 0, 0.7),
+                    0 0 30px rgba(204, 0, 0, 0.3);
+    }
+}
+
+/* Subtle screen vignette - professional urgency effect */
+body.game-critical::before {
+    content: '';
+    position: fixed;
+    inset: 0;
+    pointer-events: none;
+    z-index: 1;
+    animation: screenVignette 2s ease-in-out infinite;
+    transition: opacity 0.3s ease;
+}
+
+@keyframes screenVignette {
+    0%, 100% {
+        box-shadow: inset 0 0 100px rgba(255, 0, 0, 0.12);
+    }
+    50% {
+        box-shadow: inset 0 0 140px rgba(255, 0, 0, 0.18);
+    }
+}
+
+/* Light theme vignette - more subtle */
+[data-theme="light"] body.game-critical::before {
+    animation: screenVignetteLight 2s ease-in-out infinite;
+}
+
+@keyframes screenVignetteLight {
+    0%, 100% {
+        box-shadow: inset 0 0 120px rgba(204, 0, 0, 0.08);
+    }
+    50% {
+        box-shadow: inset 0 0 160px rgba(204, 0, 0, 0.12);
+    }
 }
 
 .stars {
diff --git a/src/js/app.js b/src/js/app.js
index 113abda..1cfb69e 100644
--- a/src/js/app.js
+++ b/src/js/app.js
@@ -175,12 +175,26 @@
       timeEl.textContent = formatTime(Math.floor(timeLeft / 60), timeLeft % 60);
       const pct = Math.max(0, (timeLeft / timeTotal) * 100);
       timerBarFill.style.width = pct + '%';
+
+      // Game-style urgent warning at 10 seconds
       if (timeLeft === 10) {
-         alert("Hurry up! Only 10 seconds left!");
+        playTone(800, 0.15); // warning sound
+        timeEl.classList.add('timer-critical');
+        timerBarFill.classList.add('timer-bar-critical');
+        document.body.classList.add('game-critical');
       }
     }, 1000);
   }
-  function stopTimer() { if (timerId) { clearInterval(timerId); timerId = null } }
+  function stopTimer() {
+    if (timerId) {
+      clearInterval(timerId);
+      timerId = null;
+      // Remove critical state when timer stops
+      timeEl.classList.remove('timer-critical');
+      timerBarFill.classList.remove('timer-bar-critical');
+      document.body.classList.remove('game-critical');
+    }
+  }
   function resetTimer() {
     stopTimer();
     pairCount = Math.floor(difficulties[selectedDifficulty].tiles / 2);
@@ -189,6 +203,10 @@
     timeLeft = timeTotal;
     timeEl.textContent = formatTime(Math.floor(timeLeft / 60), timeLeft % 60);
     timerBarFill.style.width = '100%';
+    // Remove all critical classes
+    timeEl.classList.remove('timer-critical');
+    timerBarFill.classList.remove('timer-bar-critical');
+    document.body.classList.remove('game-critical');
   }
 
   // audio helpers (small tones using WebAudio)