/* 全局变量与重置 */
:root {
    --primary-color: #2e7d32;
    --primary-dark: #1b5e20;
    --text-color: #333;
    --light-bg: #f9f9f9;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Microsoft YaHei', sans-serif; color: var(--text-color); line-height: 1.6; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.section { padding: 5rem 0; }
.section-title { text-align: center; font-size: clamp(1.6rem, 5vw, 2.5rem); margin-bottom: 1rem; color: var(--primary-dark); }
.section-desc { text-align: center; max-width: 800px; margin: 0 auto 3rem; font-size: 1.1rem; color: #666; }
.btn-primary { 
    display: inline-block; padding: 1rem 2rem; background: var(--primary-color); color: #fff; 
    text-decoration: none; border-radius: 50px; font-size: 1.1rem; transition: 0.3s; border: none; cursor: pointer;
}
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-3px); }

/* 导航栏 */
.header { position: fixed; top: 0; width: 100%; background: rgba(255,255,255,0.95); z-index: 1000; box-shadow: 0 2px 10px rgba(0,0,0,0.1); }
.nav-container { display: flex; justify-content: space-between; align-items: center; height: 70px; }
.logo { text-decoration: none; display: flex; align-items: center; }
.logo img { height: 40px; width: auto; display: block; }
.nav-menu a { text-decoration: none; color: var(--text-color); margin-left: 2rem; transition: 0.3s; }
.nav-menu a:hover, .nav-cta { color: var(--primary-color); }
.nav-cta { background: var(--primary-color); color: #fff !important; padding: 0.5rem 1.2rem; border-radius: 20px; }
.hamburger { display: none; background: none; border: none; cursor: pointer; }
.hamburger span { display: block; width: 25px; height: 3px; background: #333; margin: 5px 0; transition: 0.3s; }

/* 首屏 */
.hero { 
    min-height: 100vh; display: flex; align-items: center; justify-content: center; text-align: center; color: #fff;
    background: linear-gradient(rgba(0,0,0,0.4), rgba(0,0,0,0.4)), url('../images/hero-bg.jpg') center/cover no-repeat;
}
.hero-content h1 { font-size: clamp(2rem, 5vw, 3.5rem); margin-bottom: 1rem; }
.hero-content p { font-size: clamp(1rem, 2vw, 1.5rem); margin-bottom: 2rem; opacity: 0.9; }

/* 关于我们（PDF版式：左文右图 + 底部数据） */
.about {}
.about-container { display: grid; grid-template-columns: 1.15fr 1fr; gap: 3rem; align-items: center; }
.about-title { font-size: clamp(1.8rem, 4vw, 2.5rem); line-height: 1.25; color: #1b7a3f; margin-bottom: 0.4rem; text-align: left; }
.about-subtitle { font-size: 1rem; letter-spacing: 0.5px; color: #333; margin-bottom: 1.5rem; }
.about-text { color: #4a3a28; text-align: justify; margin-bottom: 1rem; }
.about-image img { width: 100%; display: block; border-radius: 8px; box-shadow: 0 12px 30px rgba(0,0,0,0.25); }
.about-metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; margin-top: 3rem; }
.about-metric { padding-left: 1.5rem; border-left: 2px solid rgba(27,122,63,0.4); }
.about-metric:first-child { padding-left: 0; border-left: none; }
.about-metric h3 { font-size: clamp(1.6rem, 3vw, 2.4rem); font-weight: 800; color: #1b7a3f; line-height: 1.2; }
.about-metric h3 small { font-size: 0.5em; margin-left: 2px; }
.about-metric p { font-size: 0.9rem; color: #4a3a28; margin-top: 0.3rem; }

/* 发展历程时间轴 */
.milestones { background: #fdf6ee; }
.section-subtitle-en { text-align: center; letter-spacing: 3px; color: #999; font-size: 0.95rem; margin-top: -0.5rem; }
.timeline { position: relative; display: grid; grid-template-columns: repeat(6, 1fr); gap: 1.5rem; margin-top: 3.5rem; }
.timeline::before { content: ''; position: absolute; top: 9px; left: 1%; right: 1%; height: 4px; border-radius: 2px; background: linear-gradient(90deg, #2e9d52, var(--primary-dark)); }
.timeline-item { position: relative; padding-top: 2.4rem; }
.timeline-item::before { content: ''; position: absolute; top: 0; left: 0; width: 13px; height: 13px; border-radius: 50%; background: #fff; border: 4px solid var(--primary-color); box-shadow: 0 0 0 3px rgba(46,125,50,0.15); z-index: 1; }
.timeline-item::after { content: ''; position: absolute; top: 24px; left: 10.5px; height: 14px; width: 0; border-left: 2px dotted rgba(46,125,50,0.4); }
.timeline-item h3 { font-size: 1.1rem; color: var(--primary-dark); margin-bottom: 0.6rem; }
.timeline-item ul { list-style: none; }
.timeline-item li { position: relative; padding-left: 1.1rem; margin-bottom: 0.4rem; font-size: 0.9rem; color: #555; }
.timeline-item li::before { content: '▪'; position: absolute; left: 0; color: var(--primary-color); }

/* 服务网格 */
.services-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; margin-top: 2rem; }
.service-card { background: #fff; padding: 2rem; border-radius: 12px; box-shadow: 0 4px 15px rgba(0,0,0,0.05); transition: 0.3s; }
.service-card:hover { transform: translateY(-5px); box-shadow: 0 10px 25px rgba(0,0,0,0.1); }
.service-card h3 { margin-bottom: 1rem; color: var(--primary-dark); }

/* 六维保障体系 */
.support-system { background: #fdf6ee;}
.support-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; margin-top: 2rem; }
.support-card {
    background: #fff; padding: 2rem; border-radius: 12px; border-top: 4px solid var(--primary-color);
    box-shadow: 0 4px 15px rgba(0,0,0,0.05); transition: 0.3s;
}
.support-card:hover { transform: translateY(-5px); box-shadow: 0 10px 25px rgba(0,0,0,0.1); }
.support-icon { font-size: 2rem; margin-bottom: 0.8rem; }
.support-card h3 { margin-bottom: 1rem; color: var(--primary-dark); }
.support-card ul { list-style: none; }
.support-card li { position: relative; padding-left: 1.4rem; margin-bottom: 0.5rem; font-size: 0.95rem; color: #555; }
.support-card li::before { content: '✓'; position: absolute; left: 0; color: var(--primary-color); font-weight: bold; }

/* 社交媒体样式 */
.social-media { background: var(--light-bg); text-align: center; }
.social-icons { display: flex; justify-content: center; gap: 1.5rem; margin-bottom: 3rem; flex-wrap: wrap; }
.social-icon {
    position: relative; display: inline-flex; align-items: center; justify-content: center;
    width: 60px; height: 60px; border-radius: 50%; color: #fff; font-size: 1.5rem; font-weight: bold;
    text-decoration: none; transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.social-icon:hover { transform: translateY(-5px); box-shadow: 0 8px 15px rgba(0,0,0,0.2); }
.social-icon.douyin { background: #161823; }
.social-icon.xiaohongshu { background: #ff2442; }
.social-icon.wechat { background: #07c160; }
.tooltip {
    position: absolute; bottom: 120%; left: 50%; transform: translateX(-50%);
    background: #333; color: #fff; padding: 0.5rem 1rem; border-radius: 6px;
    font-size: 0.8rem; font-weight: normal; white-space: nowrap;
    opacity: 0; visibility: hidden; transition: all 0.3s ease; pointer-events: none;
}
.tooltip::after { content: ''; position: absolute; top: 100%; left: 50%; transform: translateX(-50%); border-width: 5px; border-style: solid; border-color: #333 transparent transparent transparent; }
.social-icon:hover .tooltip { opacity: 1; visibility: visible; bottom: 130%; }

/* 二维码弹窗 */
.qr-modal {
    position: fixed; inset: 0; background: rgba(0,0,0,0.6); z-index: 2000;
    display: flex; align-items: center; justify-content: center; padding: 1rem;
    opacity: 0; visibility: hidden; transition: opacity 0.3s ease, visibility 0.3s ease;
}
.qr-modal.show { opacity: 1; visibility: visible; }
.qr-modal-content {
    background: #fff; border-radius: 12px; padding: 2.5rem 2rem 2rem; text-align: center;
    position: relative; max-width: 320px; width: 100%;
    transform: translateY(24px) scale(0.95); transition: transform 0.3s ease;
}
.qr-modal.show .qr-modal-content { transform: translateY(0) scale(1); }
.qr-close {
    position: absolute; top: 8px; right: 14px; background: none; border: none;
    font-size: 2rem; line-height: 1; color: #999; cursor: pointer; transition: 0.2s;
}
.qr-close:hover { color: #333; transform: rotate(90deg); }
.qr-modal-content h3 { color: var(--primary-dark); margin-bottom: 1.2rem; }
.qr-modal-content img {
    width: 230px; height: 230px; display: block; margin: 0 auto 1rem;
    border: 1px solid #eee; border-radius: 8px; object-fit: contain;
}
.qr-modal-content p { color: #888; font-size: 0.9rem; }
.video-container {
    position: relative; width: 100%; max-width: 900px; margin: 0 auto;
    aspect-ratio: 16 / 9; background: #000; overflow: hidden; border-radius: 12px; box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}
.video-container video { width: 100%; height: 100%; display: block; object-fit: cover; }

/* 信任背书样式 */
.trust-metrics { background: var(--primary-dark); color: #fff; text-align: center; }
.trust-metrics .section-title { color: #fff; }
.metrics-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 2rem; }
.metric-card { padding: 1.5rem; }
.metric-number { font-size: 3rem; font-weight: 700; margin-bottom: 0.5rem; color: #a5d6a7; }
.metric-label { font-size: 1.1rem; opacity: 0.9; }

/* 联系我们模块样式 */
.contact { background: var(--light-bg); }
.contact-info-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 2rem; max-width: 1000px; margin: 0 auto;
}
.contact-card {
    background: #fff; padding: 2rem; border-radius: 12px; box-shadow: 0 4px 15px rgba(0,0,0,0.05); text-align: center; transition: 0.3s;
}
.contact-card:hover { transform: translateY(-5px); box-shadow: 0 10px 25px rgba(0,0,0,0.1); }
.contact-card h4 { font-size: 1.3rem; margin-bottom: 1rem; color: var(--primary-dark); }
.contact-card p { font-size: 1.2rem; font-weight: bold; color: #333; margin-bottom: 0.5rem; }
.contact-card span { font-size: 0.9rem; color: #888; }

/* 页脚 */
.footer { text-align: center; padding: 2rem; background: #333; color: #aaa; font-size: 0.9rem; }
.footer-beian { margin-top: 0.6rem; font-size: 0.8rem; display: flex; justify-content: center; gap: 1.5rem; flex-wrap: wrap; }
.footer-beian a { color: #aaa; text-decoration: none; display: inline-flex; align-items: center; gap: 4px; transition: color 0.2s; }
.footer-beian a:hover { color: #fff; }
.beian-icon { vertical-align: middle; }

/* 返回顶部按钮样式 */
#backToTopBtn {
    position: fixed; bottom: 30px; right: 30px; width: 50px; height: 50px;
    background-color: var(--primary-color); color: #fff; border: none; border-radius: 50%;
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2); z-index: 999;
    opacity: 0; visibility: hidden; transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
}
#backToTopBtn.show { opacity: 1; visibility: visible; }
#backToTopBtn:hover { background-color: var(--primary-dark); transform: translateY(-3px); }

/* 移动端响应式 */
@media (max-width: 768px) {
    .hamburger { display: block; }
    .nav-menu {
        display: flex; flex-direction: column; align-items: center;
        position: absolute; top: 70px; left: 0; width: 100%; background: #fff;
        padding: 0 1rem;
        max-height: 0; overflow: hidden; transition: max-height 0.3s ease, padding 0.3s ease;
        box-shadow: 0 6px 12px rgba(0,0,0,0.1);
    }
    .nav-menu.active { max-height: 360px; padding: 1rem; }
    .nav-menu a { margin: 0.6rem 0; }
    .nav-menu .nav-cta { padding: 0.5rem 2rem; }
    /* 汉堡按钮展开为 X 动画 */
    .hamburger.toggle span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
    .hamburger.toggle span:nth-child(2) { opacity: 0; }
    .hamburger.toggle span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
}

/* 服务网格响应式：平板一行2项，手机一行1项 */
@media (max-width: 992px) {
    .services-grid, .support-grid { grid-template-columns: repeat(2, 1fr); }
    .about-container { grid-template-columns: 1fr; }
    .about-metrics { grid-template-columns: repeat(2, 1fr); row-gap: 2rem; }
    .about-metric:nth-child(odd) { padding-left: 0; border-left: none; }
    .timeline { grid-template-columns: 1fr; gap: 1.8rem; }
    .timeline::before { display: none; }
    .timeline-item { padding-top: 0; padding-left: 2.2rem; }
    .timeline-item::before { top: 4px; }
    .timeline-item::after { top: 28px; height: auto; bottom: -1.8rem; }
    .timeline-item:last-child::after { display: none; }
}
@media (max-width: 576px) {
    .services-grid, .support-grid { grid-template-columns: 1fr; }
}