/**
 * 相宜亲家官网 - 主脚本
 */

document.addEventListener('DOMContentLoaded', function() {
    // 导航栏滚动效果
    const header = document.querySelector('.header');
    const navLinks = document.querySelectorAll('.nav a');
    const heroSection = document.querySelector('.hero');
    
    // 滚动时改变导航栏样式
    window.addEventListener('scroll', function() {
        const heroHeight = heroSection ? heroSection.offsetHeight : 600;
        
        if (window.scrollY > heroHeight - 100) {
            header.classList.add('header-fixed');
        } else {
            header.classList.remove('header-fixed');
        }
        
        // 更新导航栏激活状态
        updateActiveNav();
    });
    
    // 平滑滚动到锚点
    navLinks.forEach(link => {
        link.addEventListener('click', function(e) {
            const targetId = this.getAttribute('href');
            
            // 只对锚点链接（以#开头）进行平滑滚动处理
            if (targetId.startsWith('#')) {
                e.preventDefault();
                const targetSection = document.querySelector(targetId);
                
                if (targetSection) {
                    const headerHeight = header.offsetHeight;
                    const targetPosition = targetSection.offsetTop - headerHeight;
                    
                    window.scrollTo({
                        top: targetPosition,
                        behavior: 'smooth'
                    });
                }
            }
            // 对于外部链接（如cases.html），让浏览器正常处理跳转
        });
    });
    
    // 更新导航栏激活状态
    function updateActiveNav() {
        const sections = document.querySelectorAll('section[id]');
        const scrollPosition = window.scrollY + 100;
        
        sections.forEach(section => {
            const sectionTop = section.offsetTop - 100;
            const sectionHeight = section.offsetHeight;
            const sectionId = section.getAttribute('id');
            
            if (scrollPosition >= sectionTop && scrollPosition < sectionTop + sectionHeight) {
                navLinks.forEach(link => {
                    const href = link.getAttribute('href');
                    // 只处理锚点链接的激活状态
                    if (href.startsWith('#')) {
                        link.classList.remove('active');
                        if (href === '#' + sectionId) {
                            link.classList.add('active');
                        }
                    }
                });
            }
        });
    }
    
    // 案例卡片动画
    const caseItems = document.querySelectorAll('.case-item');
    
    const observerOptions = {
        threshold: 0.2,
        rootMargin: '0px 0px -50px 0px'
    };
    
    const observer = new IntersectionObserver(function(entries) {
        entries.forEach(entry => {
            if (entry.isIntersecting) {
                entry.target.style.opacity = '1';
                entry.target.style.transform = 'translateY(0)';
            }
        });
    }, observerOptions);
    
    caseItems.forEach((item, index) => {
        item.style.opacity = '0';
        item.style.transform = 'translateY(30px)';
        item.style.transition = `all 0.5s ease ${index * 0.1}s`;
        observer.observe(item);
    });
    
    // 特性项动画
    const featureItems = document.querySelectorAll('.feature-item');
    
    featureItems.forEach((item, index) => {
        item.style.opacity = '0';
        item.style.transform = 'translateX(-30px)';
        item.style.transition = `all 0.5s ease ${index * 0.15}s`;
        observer.observe(item);
    });
});