/* 全局基础样式 + 黑白模式变量 */
:root {
    --primary: #0066cc;
    --primary-dark: #004a99;
    --bg-white: #fff;
    --bg-gray: #f5f7fa;
    --text-main: #1d2129;
    --text-secondary: #666;
    --border: #eee;
    --shadow: 0 5px 15px rgba(0,0,0,0.1);
    --transition: all 0.3s ease;
}
.dark-mode {
    --primary: #8ab4f8;
    --primary-dark: #5f99f7;
    --bg-white: #121212;
    --bg-gray: #1e1e1e;
    --text-main: #e0e0e0;
    --text-secondary: #b0b0b0;
    --border: #333;
    --shadow: 0 5px 15px rgba(0,0,0,0.3);
}
* { margin: 0; padding: 0; box-sizing: border-box; font-family: "Microsoft YaHei", sans-serif; }
body { 
    background: var(--bg-white); 
    color: var(--text-main); 
    transition: var(--transition);
    scroll-behavior: smooth;
}
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
a { text-decoration: none; color: inherit; }
button { cursor: pointer; border: none; background: none; }
.section-title { text-align: center; font-size: 32px; margin-bottom: 40px; color: var(--text-main); }
.btn-primary { background: var(--primary); color: #fff; padding: 12px 24px; border-radius: 4px; font-size: 16px; transition: var(--transition); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-2px); }
.btn-secondary { background: transparent; color: var(--primary); border: 1px solid var(--primary); padding: 12px 24px; border-radius: 4px; font-size: 16px; transition: var(--transition); }
.btn-secondary:hover { background: rgba(0, 102, 204, 0.1); }
/* 动态模糊容器 */
.blur-container {
    position: relative;
    overflow: hidden;
    z-index: 1;
}
.blur-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 120%;
    height: 120%;
    filter: blur(15px);
    opacity: 0.2;
    z-index: -1;
    transform: scale(1.1);
    transition: var(--transition);
}
.blur-container:hover .blur-bg {
    transform: scale(1.2);
    opacity: 0.3;
}
/* 黑白模式切换按钮 */
.theme-toggle {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--bg-white);
    color: var(--text-main);
    box-shadow: var(--shadow);
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: var(--transition);
}
.theme-toggle:hover {
    transform: scale(1.1);
    background: var(--primary);
    color: #fff;
}
/* 顶部导航 */
.header { 
    background: var(--bg-white); 
    border-bottom: 1px solid var(--border); 
    position: sticky; 
    top: 0; 
    z-index: 999;
    transition: var(--transition);
}
.nav { display: flex; justify-content: space-between; align-items: center; height: 70px; }
.logo { font-size: 22px; font-weight: bold; color: var(--primary); }
.nav-list { display: flex; list-style: none; }
.nav-item { margin: 0 15px; position: relative; }
.nav-item > a { 
    display: block; 
    height: 70px; 
    line-height: 70px; 
    font-size: 15px; 
    font-weight: 500; 
    transition: var(--transition);
}
.nav-item > a:hover { color: var(--primary); }
.submenu { 
    position: absolute; 
    top: 70px; 
    left: 50%; 
    transform: translateX(-50%); 
    min-width: 120px; 
    background: var(--bg-white); 
    border-radius: 8px; 
    box-shadow: var(--shadow); 
    padding: 10px 0; 
    display: none; 
    z-index: 9999;
    border: 1px solid var(--border);
    transition: var(--transition);
}
.submenu li { text-align: center; padding: 0 15px; }
.submenu a { 
    display: block; 
    padding: 8px 0; 
    font-size: 13px; 
    color: var(--text-secondary);
    transition: var(--transition);
}
.submenu a:hover { 
    color: var(--primary); 
    background: rgba(0, 102, 204, 0.05); 
}
.nav-item:hover .submenu { display: block; }
.nav-btn { background: var(--primary); color: #fff; padding: 6px 14px; border-radius: 4px; margin-left: 10px; font-size: 14px; }
.mobile-menu-btn { display: none; font-size: 24px; color: var(--text-main); }
/* Banner 区 */
.banner { 
    height: 400px; 
    display: flex; 
    align-items: center;
    background: linear-gradient(135deg, var(--bg-gray), rgba(0, 102, 204, 0.05));
    transition: var(--transition);
}
.banner-content { width: 70%; }
.banner h1 { 
    font-size: 36px; 
    margin-bottom: 15px; 
    line-height: 1.3;
    color: var(--text-main);
}
.banner p { 
    font-size: 16px; 
    color: var(--text-secondary); 
    margin-bottom: 25px; 
    line-height: 1.6;
}
.banner-btn { display: flex; gap: 15px; }
/* 时间线 */
.timeline-banner { 
    background: var(--bg-gray); 
    padding: 60px 0; 
    margin: 20px 0;
    transition: var(--transition);
}
.timeline-container { position: relative; max-width: 1100px; margin: 0 auto; padding: 0 30px; }
.timeline { 
    position: relative; 
    padding: 30px 0; 
    opacity: 0; 
    animation: fadeIn 1.5s ease forwards; 
    animation-delay: 0.3s;
    display: flex;
    justify-content: space-around;
    align-items: center;
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
.timeline::before { 
    content: ''; 
    position: absolute; 
    top: 50%; 
    left: 5%; 
    right: 5%; 
    height: 3px; 
    background: linear-gradient(90deg, transparent, var(--primary), transparent); 
    z-index: 1; 
    transform: translateY(-50%); 
}
.timeline-item { 
    position: relative; 
    z-index: 2; 
    text-align: center; 
    width: 18%; 
    padding: 0 10px; 
    opacity: 0;
    animation: fadeInItem 1s ease forwards;
}
.timeline-item:nth-child(1) { animation-delay: 0.5s; }
.timeline-item:nth-child(2) { animation-delay: 0.7s; }
.timeline-item:nth-child(3) { animation-delay: 0.9s; }
.timeline-item:nth-child(4) { animation-delay: 1.1s; }
.timeline-item:nth-child(5) { animation-delay: 1.3s; }
@keyframes fadeInItem {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}
.timeline-dot { 
    width: 22px; 
    height: 22px; 
    background: var(--bg-white); 
    border: 3px solid var(--primary); 
    border-radius: 50%; 
    margin: 0 auto 12px; 
    transition: var(--transition);
    box-shadow: 0 0 0 4px rgba(0, 102, 204, 0.1);
}
.timeline-item:hover .timeline-dot {
    transform: scale(1.2);
    box-shadow: 0 0 0 6px rgba(0, 102, 204, 0.15);
}
.timeline-date { 
    font-size: 13px; 
    color: var(--primary); 
    margin-bottom: 6px; 
    font-weight: 500;
}
.timeline-year { 
    font-weight: bold; 
    margin-bottom: 8px; 
    font-size: 16px; 
}
.timeline-desc { 
    font-size: 13px; 
    color: var(--text-secondary); 
    line-height: 1.5;
}
/* 核心业务 */
.business { padding: 80px 0; }
.business-cards { display: flex; gap: 30px; }

.card { 
    flex: 1; 
    border: 1px solid var(--border); 
    border-radius: 8px; 
    padding: 30px; 
    text-align: center; 
    transition: var(--transition);
    background: var(--bg-white);
}
.card:hover { 
    box-shadow: var(--shadow); 
    transform: translateY(-5px);
}
.card-icon { 
    width: 40px; 
    height: 40px; 
    margin: 0 auto 15px; 
    background: var(--primary); 
    border-radius: 6px; 
    display: flex; 
    align-items: center; 
    justify-content: center; 
    color: #fff; 
    font-size: 20px;
}
.card h3 { font-size: 18px; margin-bottom: 12px; }
.card p { color: var(--text-secondary); line-height: 1.5; font-size: 14px; }
/* 项目风采（幻灯片） */
.slide-show { 
    padding: 60px 0; 
    background: var(--bg-gray);
    transition: var(--transition);
}
.slider-container { 
    position: relative; 
    width: 100%; 
    height: 300px; 
    overflow: hidden; 
    border-radius: 8px; 
    box-shadow: var(--shadow);
}
.slide { 
    position: absolute; 
    top: 0; 
    left: 0; 
    width: 100%; 
    height: 100%; 
    opacity: 0; 
    transition: opacity 0.5s ease;
}
.slide.active { opacity: 1; }
.slide img { width: 100%; height: 100%; object-fit: cover; }
.slide-caption { 
    position: absolute; 
    bottom: 0; 
    left: 0; 
    right: 0; 
    background: rgba(0,0,0,0.6); 
    color: #fff; 
    padding: 15px; 
    font-size: 15px;
}
.slider-btn { 
    position: absolute; 
    top: 50%; 
    transform: translateY(-50%); 
    background: rgba(255,255,255,0.7); 
    width: 36px; 
    height: 36px; 
    border-radius: 50%; 
    z-index: 10; 
    font-size: 18px; 
    color: #333;
}
.prev-btn { left: 15px; }
.next-btn { right: 15px; }
.slider-dots { 
    position: absolute; 
    bottom: 15px; 
    left: 50%; 
    transform: translateX(-50%); 
    display: flex; 
    gap: 8px; 
    z-index: 10; 
}
.slider-dot { 
    width: 10px; 
    height: 10px; 
    border-radius: 50%; 
    background: rgba(255,255,255,0.5); 
    cursor: pointer; 
}
.slider-dot.active { background: #fff; }
/* 技术实力 */
.tech { 
    padding: 80px 0; 
    background: var(--bg-white);
    transition: var(--transition);
}
.tech-content { display: flex; align-items: center; gap: 40px; }
.tech-text { flex: 1; }
.tech-text h3 { font-size: 24px; margin-bottom: 15px; }
.tech-text p { color: var(--text-secondary); line-height: 1.5; margin-bottom: 15px; font-size: 14px; }
.tech-data { display: flex; gap: 30px; margin-top: 20px; }
.data-item { text-align: center; }
.data-num { font-size: 28px; font-weight: bold; color: var(--primary); }
.data-text { color: var(--text-secondary); font-size: 13px; }
.tech-img { flex: 1; }
.tech-img img { width: 100%; border-radius: 8px; box-shadow: var(--shadow); }
/* 案例展示 */
.cases { padding: 80px 0; }
.cases-list { display: flex; flex-wrap: wrap; gap: 25px; }
.case-item { 
    width: calc(33.333% - 17px); 
    border-radius: 8px; 
    overflow: hidden; 
    border: 1px solid var(--border);
    background: var(--bg-white);
    transition: var(--transition);
}
.case-item:hover { box-shadow: var(--shadow); }
.case-item img { width: 100%; height: 160px; object-fit: cover; }
.case-info { padding: 15px; }
.case-info h4 { font-size: 16px; margin-bottom: 8px; }
.case-info p { color: var(--text-secondary); font-size: 13px; line-height: 1.5; }
/* 关于我们 */
.about { 
    padding: 80px 0; 
    background: linear-gradient(135deg, var(--primary), var(--primary-dark)); 
    color: #fff;
}
.about-content { text-align: center; width: 90%; margin: 0 auto; }
.about h3 { font-size: 26px; margin-bottom: 20px; }
.about p { font-size: 15px; line-height: 1.7; margin-bottom: 30px; opacity: 0.9; }
.about .btn-secondary { color: #fff; border-color: #fff; }
.about .btn-secondary:hover { background: rgba(255,255,255,0.1); }
/* 联系我们 */
.contact { padding: 80px 0; background: var(--bg-white); transition: var(--transition); }
.contact-wrap { max-width: 1000px; margin: 0 auto; }
.contact-title { text-align: center; font-size: 32px; margin-bottom: 15px; }
.contact-subtitle { text-align: center; color: var(--text-secondary); font-size: 15px; margin-bottom: 50px; }
.contact-content { display: flex; gap: 30px; }
.contact-form { 
    flex: 1; 
    background: var(--bg-gray); 
    padding: 40px 35px; 
    border-radius: 12px; 
    border: 1px solid var(--border);
    transition: var(--transition);
}
.form-header { 
    font-size: 20px; 
    margin-bottom: 25px; 
    font-weight: 600; 
    border-left: 3px solid var(--primary); 
    padding-left: 12px;
}
.form-group { margin-bottom: 20px; }
.form-group label { 
    display: block; 
    margin-bottom: 8px; 
    font-weight: 500; 
    color: var(--text-main); 
    font-size: 14px; 
}
.form-group input, .form-group textarea { 
    width: 100%; 
    padding: 12px 15px; 
    border: 1px solid var(--border); 
    border-radius: 6px; 
    font-size: 14px; 
    transition: var(--transition);
    background: var(--bg-white);
    color: var(--text-main);
}
.form-group input:focus, .form-group textarea:focus { 
    outline: none; 
    border-color: var(--primary); 
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1); 
}
.form-group textarea { height: 120px; resize: none; line-height: 1.5; }
/* 验证码样式 */
.captcha-group {
    margin-bottom: 20px;
}

.captcha-group img {
    cursor: pointer;
    border: 1px solid var(--border);
    border-radius: 6px;
    transition: var(--transition);
}

.captcha-group img:hover {
    border-color: var(--primary);
}

.captcha-group small {
    color: var(--text-secondary);
    font-size: 12px;
    margin-top: 8px;
    display: block;
    cursor: pointer;
    transition: var(--transition);
}

.captcha-group small:hover {
    color: var(--primary);
}
.submit-btn { 
    width: 100%; 
    background: var(--primary); 
    color: #fff; 
    padding: 12px 0; 
    border-radius: 6px; 
    font-size: 16px; 
    font-weight: 500; 
    transition: var(--transition);
}
.submit-btn:hover { background: var(--primary-dark); transform: translateY(-2px); }
.success-message { 
    color: #28a745; 
    margin-top: 15px; 
    display: none; 
    font-size: 14px; 
    text-align: center; 
    padding: 8px 0; 
}
.contact-info { flex: 1; display: flex; flex-direction: column; gap: 30px; }
.info-card { 
    background: linear-gradient(135deg, var(--primary), var(--primary-dark)); 
    color: #fff; 
    padding: 35px; 
    border-radius: 12px; 
    height: 100%; 
    display: flex; 
    flex-direction: column; 
    gap: 25px;
}
.info-header { font-size: 20px; font-weight: 600; margin-bottom: 8px; }
.info-desc { font-size: 14px; opacity: 0.9; line-height: 1.6; }
.info-list { list-style: none; display: flex; flex-direction: column; gap: 20px; }
.info-item { display: flex; align-items: flex-start; gap: 15px; }
.info-icon { 
    width: 22px; 
    height: 22px; 
    margin-top: 2px; 
    opacity: 0.9; 
    display: flex; 
    align-items: center; 
    justify-content: center; 
    background: rgba(255,255,255,0.2); 
    border-radius: 4px; 
    font-size: 14px;
}
.info-text { font-size: 14px; }
.work-time { 
    margin-top: 8px; 
    padding-top: 15px; 
    border-top: 1px solid rgba(255, 255, 255, 0.2); 
    font-size: 13px; 
    opacity: 0.8; 
}
/* 底部（纯图片logo样式） */
.footer { 
    background: #1d2129; 
    color: #999; 
    padding: 50px 0 20px; 
    position: relative;
    overflow: hidden;
    z-index: 1;
}
.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 120%;
    height: 120%;
    filter: blur(15px);
    opacity: 0.1;
    z-index: -1;
    transform: scale(1.1);
    transition: var(--transition);
    background: url('https://picsum.photos/id/104/1200/600') center center no-repeat;
    background-size: cover;
}
.footer:hover::before {
    transform: scale(1.2);
    opacity: 0.2;
}
/* 页脚居中纯图片logo样式 */
.footer-logo {
    text-align: center;
    margin-bottom: 100px;
}
.footer-logo-img {
    width: 150px; /* 可根据logo实际尺寸调整 */
    height: auto;
    display: inline-block;
}
.footer-top { display: flex; justify-content: space-between; margin-bottom: 30px; flex-wrap: wrap; gap: 30px; }
.footer-contact { flex: 1; min-width: 250px; }
.footer-contact h4 { font-size: 16px; color: #fff; margin-bottom: 15px; }
.footer-contact p { margin: 8px 0; font-size: 13px; }
.wechat-qrcode { margin-top: 15px; }
.wechat-qrcode img { width: 100px; height: 100px; border-radius: 4px; }
.wechat-qrcode p { text-align: center; margin-top: 5px; font-size: 12px; color: #ccc; }
.footer-links { display: flex; gap: 40px; flex: 1; min-width: 300px; }
.footer-links h4 { font-size: 16px; color: #fff; margin-bottom: 15px; }
.footer-links ul { list-style: none; }
.footer-links li { margin: 8px 0; }
.footer-links a { 
    color: #999; 
    transition: var(--transition);
    font-size: 13px;
}
.footer-links a:hover { color: #fff; }
.footer-bottom { 
    text-align: center; 
    padding-top: 15px; 
    border-top: 1px solid #333; 
    font-size: 12px; 
}
.record-links { margin-top: 8px; }
.record-links a { color: #666; margin: 0 8px; transition: var(--transition); }
.record-links a:hover { color: #999; }
/* 响应式适配 */
@media (max-width: 1024px) {
    .banner-content { width: 80%; }
    .banner h1 { font-size: 32px; }
    .business-cards { gap: 20px; }
    .tech-content { flex-direction: column; gap: 30px; }
    .case-item { width: calc(50% - 12px); }
    .footer-top { flex-direction: column; gap: 30px; }
    .contact-content { flex-direction: column; gap: 30px; }
    .contact { padding: 60px 0; }
    .contact-subtitle { margin-bottom: 40px; }
    .timeline { flex-wrap: wrap; gap: 25px; }
    .timeline-item { width: 45%; }
    .timeline::before { display: none; }
}
@media (max-width: 767px) {
    .nav-list { 
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--bg-white);
        flex-direction: column;
        align-items: center;
        padding: 15px 0;
        box-shadow: var(--shadow);
        opacity: 0;
        transform: translateY(-10px);
        transition: opacity 0.3s ease, transform 0.3s ease;
        visibility: hidden;
    }
    .nav-item { margin: 8px 0; }
    .nav-item > a { height: auto; line-height: normal; padding: 6px 0; }
    .submenu { position: static; transform: none; box-shadow: none; padding: 5px 0; border-top: 1px solid var(--border); }
    .nav-list.active { 
        display: flex;
        opacity: 1;
        transform: translateY(0);
        visibility: visible;
    }
    .nav-btn { margin-left: 8px; padding: 4px 10px; font-size: 13px; }
    .nav-right .nav-btn { display: inline-block; }
    .mobile-menu-btn { display: block; }
    .banner { height: auto; padding: 40px 0; }
    .banner-content { width: 100%; }
    .banner h1 { font-size: 26px; }
    .banner p { font-size: 14px; }
    .banner-btn { flex-direction: column; gap: 12px; }
    .section-title { font-size: 26px; margin-bottom: 30px; }
    .business { padding: 60px 0; }
    .business-cards { flex-direction: column; gap: 15px; }
    .tech { padding: 60px 0; }
    .tech-data { flex-direction: column; gap: 15px; }
    .cases { padding: 60px 0; }
    .case-item { width: 100%; }
    .about { padding: 60px 0; }
    .about-content { width: 100%; }
    .about h3 { font-size: 22px; }
    .footer-links { flex-direction: column; gap: 20px; }
    .contact-form, .info-card { padding: 30px 20px; }
    .contact-title { font-size: 26px; }
    .contact-subtitle { font-size: 14px; }
    .form-header, .info-header { font-size: 18px; }
    .timeline-item { width: 100%; }
    .slider-container { height: 220px; }
    .slide-caption { font-size: 13px; padding: 12px; }
    /* 响应式调整logo大小 */
    .footer-logo-img { width: 120px; }
}
/* 打字效果 */
.typing-effect { 
    overflow: hidden; 
    border-right: 2px solid var(--primary); 
    white-space: nowrap; 
    animation: typing 2.5s steps(25, end), blink 0.75s step-end infinite; 
}
@keyframes typing {
    from { width: 0; }
    to { width: 100%; }
}
@keyframes blink {
    from, to { border-color: transparent; }
    50% { border-color: var(--primary); }
}