fix: replace scroll-then-snap with direction-based one-screen-at-a-time navigation

index.html

@@ -974,106 +974,115 @@
 
         // 移动端：入场动画 + 视差滚动
         if (window.innerWidth <= 900) {
-            // 移除 CSS scroll-snap（不可靠），用 JS 实现
+            // 3. 逐屏滚动 - 方向感知，禁止自由滚动
-            document.body.style.scrollSnapType = 'none';
-            document.querySelectorAll('[style*="scroll-snap"]').forEach(el => {
-                el.style.scrollSnapType = 'none';
-                el.style.scrollSnapAlign = 'none';
-                el.style.scrollSnapStop = 'normal';
-            });
-
-            // 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 => {
-                    if (entry.isIntersecting) entry.target.classList.add('in-view');
-                });
-            }, { 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 => {
-                    const card = num.parentElement;
-                    if (!card) return;
-                    const rect = card.getBoundingClientRect();
-                    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 });
-            updateParallax();
-
-            // 3. JS 逐屏吸附
-            // 收集所有吸附点
             const snapTargets = [];
-            // Hero
             const hero = document.querySelector('.hero');
             if (hero) snapTargets.push(hero);
-            // 痛点每个卡片
             document.querySelectorAll('#pain-points .pain-item').forEach(item => snapTargets.push(item));
-            // 其他 section
             ['solutions', 'approach', 'geo', 'contact'].forEach(id => {
                 const el = document.getElementById(id);
                 if (el) snapTargets.push(el);
             });
 
-            let scrollEndTimer = null;
+            let currentIndex = 0;
-            let isSnapping = false;
+            let isAnimating = false;
             let touchStartY = 0;
-            let lastScrollTop = 0;
+            let touchStartX = 0;
+            let animFrame = null;
 
-            document.addEventListener('touchstart', (e) => {
+            // 找到离视口顶部最近的 section 索引
-                touchStartY = e.touches[0].clientY;
+            function findCurrentIndex() {
-            }, { passive: true });
+                let best = 0;
-
+                let bestDist = Infinity;
-            window.addEventListener('scroll', () => {
+                snapTargets.forEach((target, i) => {
-                // 清除之前的定时器
+                    const top = target.getBoundingClientRect().top + window.scrollY;
-                clearTimeout(scrollEndTimer);
+                    const dist = Math.abs(top - window.scrollY);
-                // 300ms 无滚动视为停止
+                    if (dist < bestDist) {
-                scrollEndTimer = setTimeout(() => {
+                        bestDist = dist;
-                    if (isSnapping) return; // 正在吸附中不触发
+                        best = i;
-                    snapToNearest();
-                }, 200);
-                lastScrollTop = window.scrollY;
-            }, { passive: true });
-
-            function snapToNearest() {
-                const vh = window.innerHeight;
-                const center = window.scrollY + vh * 0.4; // 吸附点偏上 40% 位置
-
-                let nearest = null;
-                let minDist = Infinity;
-
-                snapTargets.forEach(target => {
-                    const rect = target.getBoundingClientRect();
-                    const top = rect.top + window.scrollY;
-                    const dist = Math.abs(top - center);
-                    if (dist < minDist) {
-                        minDist = dist;
-                        nearest = target;
                     }
                 });
+                return best;
+            }
 
-                if (nearest) {
+            // 切换到指定 section
-                    isSnapping = true;
+            function goTo(index) {
-                    const targetY = nearest.getBoundingClientRect().top + window.scrollY;
+                if (index < 0 || index >= snapTargets.length || isAnimating) return;
-                    window.scrollTo({ top: targetY, behavior: 'smooth' });
+                isAnimating = true;
-                    // 吸附完成后解锁
+                const targetY = snapTargets[index].getBoundingClientRect().top + window.scrollY;
-                    setTimeout(() => { isSnapping = false; }, 800);
+                const startY = window.scrollY;
+                const diff = targetY - startY;
+                const duration = 600;
+                const startTime = performance.now();
+
+                // 自定义缓动：先快后慢，有惯性感觉
+                function easeOutCubic(t) {
+                    return 1 - Math.pow(1 - t, 3);
+                }
+
+                function step(now) {
+                    const elapsed = now - startTime;
+                    const progress = Math.min(elapsed / duration, 1);
+                    const eased = easeOutCubic(progress);
+                    window.scrollTo(0, startY + diff * eased);
+                    if (progress < 1) {
+                        animFrame = requestAnimationFrame(step);
+                    } else {
+                        isAnimating = false;
+                        currentIndex = index;
                     }
                 }
+                animFrame = requestAnimationFrame(step);
+            }
+
+            // 初始化
+            currentIndex = findCurrentIndex();
+
+            // 完全接管触摸滚动 - 禁止原生滚动
+            let canScroll = true;
+            document.addEventListener('touchmove', (e) => {
+                e.preventDefault();
+            }, { passive: false });
+
+            document.addEventListener('touchstart', (e) => {
+                if (!canScroll || isAnimating) return;
+                touchStartY = e.touches[0].clientY;
+                touchStartX = e.touches[0].clientX;
+            }, { passive: true });
+
+            document.addEventListener('touchend', (e) => {
+                if (!canScroll || isAnimating) return;
+                const dy = touchStartY - e.changedTouches[0].clientY;
+                const dx = touchStartX - e.changedTouches[0].clientX;
+
+                // 水平滑动不处理（可能是浏览器前进后退手势）
+                if (Math.abs(dx) > Math.abs(dy)) return;
+                // 最小滑动阈值，防止误触
+                if (Math.abs(dy) < 40) return;
+
+                if (dy > 0) {
+                    // 上滑 -> 下一屏
+                    goTo(currentIndex + 1);
+                } else {
+                    // 下滑 -> 上一屏
+                    goTo(currentIndex - 1);
+                }
+            }, { passive: true });
+
+            // 导航链接点击：定位到对应 section 并更新索引
+            document.querySelectorAll('.nav-links a, .btn').forEach(link => {
+                link.addEventListener('click', (e) => {
+                    const href = link.getAttribute('href');
+                    if (!href || !href.startsWith('#')) return;
+                    const targetId = href.substring(1);
+                    const idx = snapTargets.findIndex(t => t.id === targetId);
+                    if (idx >= 0) {
+                        e.preventDefault();
+                        currentIndex = idx;
+                        goTo(idx);
+                    }
+                });
+            });
         }
     </script>
 </body>