Update game.js

game.js

@@ -1293,6 +1293,61 @@ class Game {
         const existingStallWarnings = document.querySelectorAll('.stall-escape-warning');
         existingStallWarnings.forEach(w => w.remove());
         
+        // 고도 경고 외곽 효과
+        let altitudeEdgeEffect = document.getElementById('altitudeEdgeEffect');
+        if (this.fighter.altitude < 500) {
+            if (!altitudeEdgeEffect) {
+                altitudeEdgeEffect = document.createElement('div');
+                altitudeEdgeEffect.id = 'altitudeEdgeEffect';
+                document.body.appendChild(altitudeEdgeEffect);
+            }
+            
+            let edgeIntensity;
+            if (this.fighter.altitude < 250) {
+                // PULL UP 경고 - 강한 붉은 효과
+                edgeIntensity = 0.6;
+                altitudeEdgeEffect.style.cssText = `
+                    position: fixed;
+                    top: 0;
+                    left: 0;
+                    width: 100%;
+                    height: 100%;
+                    pointer-events: none;
+                    z-index: 1300;
+                    background: radial-gradient(ellipse at center, 
+                        transparent 40%, 
+                        rgba(255, 0, 0, ${edgeIntensity * 0.3}) 60%, 
+                        rgba(255, 0, 0, ${edgeIntensity}) 100%);
+                    box-shadow: inset 0 0 150px rgba(255, 0, 0, ${edgeIntensity}),
+                               inset 0 0 100px rgba(255, 0, 0, ${edgeIntensity * 0.8});
+                    animation: pulse-red 0.5s infinite;
+                `;
+            } else {
+                // LOW ALTITUDE 경고 - 약한 붉은 효과
+                edgeIntensity = 0.3;
+                altitudeEdgeEffect.style.cssText = `
+                    position: fixed;
+                    top: 0;
+                    left: 0;
+                    width: 100%;
+                    height: 100%;
+                    pointer-events: none;
+                    z-index: 1300;
+                    background: radial-gradient(ellipse at center, 
+                        transparent 50%, 
+                        rgba(255, 0, 0, ${edgeIntensity * 0.2}) 70%, 
+                        rgba(255, 0, 0, ${edgeIntensity}) 100%);
+                    box-shadow: inset 0 0 100px rgba(255, 0, 0, ${edgeIntensity}),
+                               inset 0 0 50px rgba(255, 0, 0, ${edgeIntensity * 0.5});
+                `;
+            }
+        } else {
+            // 고도가 안전하면 효과 제거
+            if (altitudeEdgeEffect) {
+                altitudeEdgeEffect.remove();
+            }
+        }
+        
         if (this.fighter.warningBlinkState) {
             const warningContainer = document.createElement('div');
             warningContainer.className = 'warning-message';
@@ -1389,6 +1444,14 @@ class Game {
                                        0 0 60px rgba(255, 0, 0, 0.8);
                         }
                     }
+                    @keyframes pulse-red {
+                        0%, 100% { 
+                            opacity: 1;
+                        }
+                        50% { 
+                            opacity: 0.7;
+                        }
+                    }
                 `;
                 document.head.appendChild(style);
             }
@@ -1581,6 +1644,11 @@ class Game {
             blurEffect.remove();
         }
         
+        const altitudeEffect = document.getElementById('altitudeEdgeEffect');
+        if (altitudeEffect) {
+            altitudeEffect.remove();
+        }
+        
         const gameOverDiv = document.createElement('div');
         gameOverDiv.className = 'start-screen';
         gameOverDiv.style.display = 'flex';