修复移动端报错：替换 closest 为 parentElement

- closest 在旧版 WebView 中可能不支持导致脚本中断
- 改用 parentElement 更安全高效
- 修复后数字视差逻辑应正常执行

index.html

@@ -365,26 +365,25 @@
                 opacity: 0.08;
                 transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1);
             }
-            /* 内容元素默认在下方（准备从下往上滑入） */
+            /* 内容元素默认在更下方（准备从下往上大幅滑入） */
             #pain-points .pain-item .pain-icon,
             #pain-points .pain-item h3,
             #pain-points .pain-item p {
                 opacity: 0;
-                transform: translateY(40px);
+                transform: translateY(60px);
-                transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
+                transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
-                            transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
+                            transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
             }
             #pain-points .pain-item .pain-icon {
-                transform: scale(0.6) translateY(40px);
+                transform: scale(0.6) translateY(60px);
             }
-            /* 数字默认在上方（准备从上往下滑入） */
+            /* 数字：默认状态由 JS 控制，这里不设 transform 避免冲突 */
             #pain-points .pain-item .pain-num {
                 opacity: 0;
-                transform: translateY(-70px);
+                transition: opacity 1s ease;
-                transition: opacity 0.9s ease, transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
             }
 
-            /* 进入视口后：内容上移，数字下落 */
+            /* 进入视口后：内容上移，数字反向坠落 */
             #pain-points .pain-item.in-view {
                 opacity: 1;
             }
@@ -396,17 +395,18 @@
             #pain-points .pain-item.in-view h3 {
                 opacity: 1;
                 transform: translateY(0);
-                transition-delay: 0.12s;
+                transition-delay: 0.1s;
             }
             #pain-points .pain-item.in-view p {
                 opacity: 1;
                 transform: translateY(0);
-                transition-delay: 0.2s;
+                transition-delay: 0.18s;
             }
+            /* 数字：越落越清晰 */
             #pain-points .pain-item.in-view .pain-num {
-                opacity: 0.15;
+                opacity: 0.3;
-                transform: translateY(0);
+                /* transform 完全由 JS 视差逻辑接管 */
-                transition-delay: 0.08s;
+                transition-delay: 0.02s;
             }
 
             /* 思路板块同样 */
@@ -563,7 +563,7 @@
                 right: 30px;
                 font-size: 110px;
                 font-weight: 900;
-                color: rgba(255,255,255,0.08);
+                color: rgba(255,255,255,0.2);
                 letter-spacing: -5px;
                 line-height: 1;
             }
@@ -952,8 +952,9 @@
         }, { threshold: 0.15, rootMargin: "0px 0px -50px 0px" });
         document.querySelectorAll('.fade-up').forEach(el => observer.observe(el));
 
-        // 移动端：轻量级 IntersectionObserver（入场错位动画由 CSS transition 处理）
+        // 移动端：入场动画 + 视差滚动
         if (window.innerWidth <= 900) {
+            // 1. 入场动画（一次性）
             const mobileItems = document.querySelectorAll('#pain-points .pain-item, #approach .approach-item');
             const mobileObserver = new IntersectionObserver((entries) => {
                 entries.forEach(entry => {
@@ -961,6 +962,42 @@
                 });
             }, { threshold: 0.05, rootMargin: "0px 0px -5% 0px" });
             mobileItems.forEach(item => mobileObserver.observe(item));
+
+            // 2. 数字编号滚动视差（基于卡片相对视口位置）
+            let ticking = false;
+            const painNums = document.querySelectorAll('#pain-points .pain-num');
+
+            function updateParallax() {
+                painNums.forEach(num => {
+                    // 获取数字所在的父卡片（.pain-item）
+                    const card = num.parentElement;
+                    if (!card) return;
+
+                    // 计算卡片相对于视口顶部的距离
+                    const rect = card.getBoundingClientRect();
+                    
+                    // 核心视差逻辑：
+                    // rect.top 越大（卡片在屏幕越下方），位移越大（向上推数字）
+                    // 随着卡片向上滚动（rect.top 变小），数字向下回落
+                    // 这会产生数字比文字"慢半拍"的悬浮感
+                    // 速度因子 0.15 意味着视差幅度为卡片移动距离的 15%
+                    const speed = 0.15;
+                    const yOffset = -(rect.top * speed);
+                    
+                    num.style.transform = `translateY(${yOffset}px)`;
+                });
+                ticking = false;
+            }
+
+            window.addEventListener('scroll', () => {
+                if (!ticking) {
+                    requestAnimationFrame(updateParallax);
+                    ticking = true;
+                }
+            }, { passive: true });
+
+            // 初始化一次
+            updateParallax();
         }
     </script>
 </body>