/* ===== 基础重置 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
    --primary: #1e6fff;
    --primary-dark: #1557cc;
    --accent: #00d4ff;
    --dark: #0f1e3d;
    --gray-900: #1a2238;
    --gray-700: #4a5568;
    --gray-500: #718096;
    --gray-300: #e2e8f0;
    --gray-100: #f7f9fc;
    --white: #ffffff;
    --gradient: linear-gradient(135deg, #1e6fff 0%, #00d4ff 100%);
    --shadow-sm: 0 2px 8px rgba(30,111,255,0.08);
    --shadow-md: 0 8px 24px rgba(15,30,61,0.12);
    --shadow-lg: 0 20px 48px rgba(15,30,61,0.18);
    --radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--gray-900);
    line-height: 1.7;
    background: var(--white);
    overflow-x: hidden;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; display: block; }
.container { max-width: 1240px; margin: 0 auto; padding: 0 24px; }

/* ===== 按钮 ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    border: 2px solid transparent;
    transition: var(--transition);
    gap: 8px;
}
.btn-primary { background: var(--gradient); color: var(--white); box-shadow: 0 6px 20px rgba(30,111,255,0.35); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(30,111,255,0.45); }
.btn-outline { background: rgba(255,255,255,0.1); color: var(--white); border-color: rgba(255,255,255,0.6); backdrop-filter: blur(8px); }
.btn-outline:hover { background: rgba(255,255,255,0.2); border-color: var(--white); transform: translateY(-2px); }
.btn-sm { padding: 10px 24px; font-size: 14px; }

/* ===== 顶部导航 ===== */
.header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}
.header.scrolled {
    background: rgba(255,255,255,0.97);
    box-shadow: var(--shadow-sm);
    border-bottom-color: var(--gray-300);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 88px;
}
.logo { display: flex; align-items: center; gap: 12px; }
.logo-img { height: 68px; width: auto; display: block; }
.logo-text { display: flex; flex-direction: column; line-height: 1.2; }
.logo-cn { font-size: 18px; font-weight: 800; color: var(--dark); letter-spacing: 1px; }
.logo-en { font-size: 10px; color: var(--gray-500); letter-spacing: 1.5px; text-transform: uppercase; }
.nav { display: flex; gap: 6px; }
.nav-link {
    padding: 8px 16px;
    font-size: 15px;
    color: var(--gray-700);
    border-radius: 8px;
    transition: var(--transition);
    font-weight: 500;
}
.nav-link:hover, .nav-link.active { color: var(--primary); background: rgba(30,111,255,0.08); }
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}
.nav-toggle span {
    width: 26px; height: 2.5px;
    background: var(--dark);
    border-radius: 2px;
    transition: var(--transition);
}

/* ===== 首屏横幅 ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    color: var(--white);
}
.hero-bg { position: absolute; inset: 0; }
.hero-bg img { width: 100%; height: 100%; object-fit: cover; }
.hero-overlay {
    position: absolute; inset: 0;
    background: linear-gradient(135deg, rgba(15,30,61,0.88) 0%, rgba(30,111,255,0.65) 100%);
}
.hero-content { position: relative; z-index: 2; padding-top: 100px; padding-bottom: 80px; }
.hero-badge {
    display: inline-block;
    padding: 6px 18px;
    background: rgba(0,212,255,0.18);
    border: 1px solid rgba(0,212,255,0.5);
    border-radius: 50px;
    font-size: 13px;
    letter-spacing: 2px;
    color: var(--accent);
    margin-bottom: 24px;
}
.hero-title {
    font-size: 56px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
}
.gradient-text {
    background: linear-gradient(90deg, #00d4ff, #6ee7ff);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero-subtitle {
    font-size: 18px;
    max-width: 640px;
    margin-bottom: 36px;
    color: rgba(255,255,255,0.85);
}
.hero-actions { display: flex; gap: 16px; margin-bottom: 60px; }
.hero-stats { display: flex; gap: 48px; flex-wrap: wrap; }
.stat-item { }
.stat-num {
    font-size: 42px;
    font-weight: 800;
    color: var(--accent);
    line-height: 1;
}
.stat-label { font-size: 14px; color: rgba(255,255,255,0.7); margin-top: 6px; }
.scroll-hint {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: rgba(255,255,255,0.7);
    font-size: 12px;
    z-index: 2;
}
.scroll-hint span {
    display: block;
    width: 24px;
    height: 38px;
    border: 2px solid rgba(255,255,255,0.5);
    border-radius: 12px;
    margin: 0 auto 8px;
    position: relative;
}
.scroll-hint span::after {
    content: '';
    position: absolute;
    top: 6px; left: 50%;
    transform: translateX(-50%);
    width: 4px; height: 8px;
    background: var(--white);
    border-radius: 2px;
    animation: scroll 1.8s infinite;
}
@keyframes scroll {
    0% { opacity: 1; transform: translate(-50%, 0); }
    100% { opacity: 0; transform: translate(-50%, 14px); }
}

/* ===== 通用区块 ===== */
.section { padding: 100px 0; }
.section-head { margin-bottom: 56px; }
.section-head.center { text-align: center; }
.section-tag {
    display: inline-block;
    font-size: 13px;
    letter-spacing: 3px;
    color: var(--primary);
    font-weight: 700;
    margin-bottom: 12px;
}
.section-title {
    font-size: 38px;
    font-weight: 800;
    color: var(--dark);
    margin-bottom: 16px;
}
.section-line {
    width: 60px; height: 4px;
    background: var(--gradient);
    border-radius: 2px;
    margin: 0 auto 20px;
}
.section-head:not(.center) .section-line { margin-left: 0; }
.section-desc { color: var(--gray-500); font-size: 16px; max-width: 640px; margin: 0 auto; }

/* ===== 关于我们 ===== */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.about-images { position: relative; }
.about-img-main img { border-radius: var(--radius); box-shadow: var(--shadow-lg); }
.about-img-sub {
    position: absolute;
    bottom: -30px; right: -30px;
    width: 220px;
    border: 8px solid var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
}
.about-img-sub img { border-radius: 4px; }
.about-img-badge {
    position: absolute;
    top: 24px; left: 24px;
    background: var(--gradient);
    color: var(--white);
    padding: 16px 22px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
}
.about-img-badge span { font-size: 32px; font-weight: 800; display: block; line-height: 1; }
.about-img-badge p { font-size: 13px; opacity: 0.9; margin-top: 4px; }
.about-text h3 { font-size: 26px; font-weight: 700; color: var(--dark); margin-bottom: 16px; }
.about-text .lead { font-size: 17px; color: var(--primary); font-weight: 600; margin-bottom: 16px; }
.about-text p { color: var(--gray-700); margin-bottom: 14px; }
.about-info { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 24px 0; padding: 20px; background: var(--gray-100); border-radius: var(--radius); }
.info-item { display: flex; flex-direction: column; gap: 2px; }
.info-label { font-size: 12px; color: var(--gray-500); }
.info-value { font-size: 15px; font-weight: 600; color: var(--dark); }

/* ===== 业务范围 ===== */
.services { background: var(--gray-100); }
.services-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.service-card {
    background: var(--white);
    padding: 36px 28px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid transparent;
}
.service-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}
.service-icon {
    width: 60px; height: 60px;
    background: linear-gradient(135deg, rgba(30,111,255,0.1), rgba(0,212,255,0.1));
    border-radius: 14px;
    display: flex; align-items: center; justify-content: center;
    margin-bottom: 20px;
    color: var(--primary);
    transition: var(--transition);
}
.service-icon svg { width: 30px; height: 30px; }
.service-card:hover .service-icon { background: var(--gradient); color: var(--white); transform: rotate(5deg); }
.service-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; color: var(--dark); }
.service-card p { font-size: 14px; color: var(--gray-500); line-height: 1.7; }

/* ===== 工程案例 ===== */
.case-tabs { display: flex; justify-content: center; gap: 12px; margin-bottom: 40px; flex-wrap: wrap; }
.case-tab {
    padding: 8px 22px;
    border: 2px solid var(--gray-300);
    background: var(--white);
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-700);
    cursor: pointer;
    transition: var(--transition);
}
.case-tab:hover { border-color: var(--primary); color: var(--primary); }
.case-tab.active { background: var(--gradient); border-color: transparent; color: var(--white); box-shadow: 0 4px 14px rgba(30,111,255,0.35); }
.case-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.case-item {
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    aspect-ratio: 3/4;
    cursor: pointer;
}
.case-item img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease; }
.case-item:hover img { transform: scale(1.08); }
.case-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(15,30,61,0.92) 0%, rgba(15,30,61,0.3) 50%, transparent 100%);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 20px;
    opacity: 0;
    transition: var(--transition);
}
.case-item:hover .case-overlay { opacity: 1; }
.case-overlay h4 { color: var(--white); font-size: 16px; font-weight: 700; margin-bottom: 4px; }
.case-overlay p { color: rgba(255,255,255,0.8); font-size: 13px; }

/* ===== 产品中心 ===== */
.products { background: var(--gray-100); }
.products-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
.product-card {
    background: var(--white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    display: flex;
}
.product-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.product-img { width: 40%; min-width: 200px; }
.product-img img { width: 100%; height: 100%; object-fit: cover; }
.product-body { padding: 28px; flex: 1; }
.product-body h3 { font-size: 20px; font-weight: 700; color: var(--dark); margin-bottom: 10px; }
.product-body > p { color: var(--gray-500); font-size: 14px; margin-bottom: 14px; }
.product-features li {
    font-size: 13px;
    color: var(--gray-700);
    padding-left: 20px;
    position: relative;
    margin-bottom: 6px;
}
.product-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: 700;
}

/* ===== 企业优势 ===== */
.adv-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.adv-item {
    padding: 36px 28px;
    border-radius: var(--radius);
    background: var(--white);
    border: 1px solid var(--gray-300);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}
.adv-item::before {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 4px;
    background: var(--gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition);
}
.adv-item:hover { border-color: var(--primary); box-shadow: var(--shadow-md); transform: translateY(-4px); }
.adv-item:hover::before { transform: scaleX(1); }
.adv-num {
    font-size: 40px;
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1;
    margin-bottom: 12px;
}
.adv-item h3 { font-size: 19px; font-weight: 700; color: var(--dark); margin-bottom: 10px; }
.adv-item p { color: var(--gray-500); font-size: 14px; }

/* ===== 联系我们 ===== */
.contact { background: var(--gray-100); }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.contact-item { display: flex; gap: 16px; margin-bottom: 28px; }
.contact-icon {
    flex-shrink: 0;
    width: 50px; height: 50px;
    background: var(--gradient);
    border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    color: var(--white);
}
.contact-icon svg { width: 24px; height: 24px; }
.contact-item h4 { font-size: 16px; font-weight: 700; color: var(--dark); margin-bottom: 4px; }
.contact-item p { color: var(--gray-500); font-size: 14px; }
.contact-license {
    background: var(--white);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow-sm);
}
.contact-license h3 { font-size: 20px; font-weight: 700; color: var(--dark); margin-bottom: 16px; }
.license-img { border-radius: 8px; overflow: hidden; margin-bottom: 20px; box-shadow: var(--shadow-sm); }
.license-info li {
    padding: 8px 0;
    border-bottom: 1px dashed var(--gray-300);
    font-size: 14px;
    color: var(--gray-700);
}
.license-info li:last-child { border-bottom: none; }
.license-info span { font-weight: 600; color: var(--dark); }

/* ===== 页脚 ===== */
.footer { background: var(--dark); color: rgba(255,255,255,0.7); padding-top: 64px; }
.footer-inner { display: grid; grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 40px; padding-bottom: 48px; }
.footer-logo { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }
.footer-logo-img { height: 72px; width: auto; display: block; }
.footer-logo span { font-size: 16px; font-weight: 700; color: var(--white); }
.footer-brand p { font-size: 14px; line-height: 1.8; }
.footer-col h4 { color: var(--white); font-size: 16px; margin-bottom: 18px; font-weight: 600; }
.footer-col ul li { font-size: 14px; margin-bottom: 10px; transition: var(--transition); }
.footer-col ul li a:hover { color: var(--accent); }
.footer-contact li { color: rgba(255,255,255,0.6); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding: 20px 0; text-align: center; font-size: 13px; color: rgba(255,255,255,0.5); }

/* ===== 回到顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: 30px; right: 30px;
    width: 48px; height: 48px;
    background: var(--gradient);
    border: none;
    border-radius: 50%;
    color: var(--white);
    cursor: pointer;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
    display: flex; align-items: center; justify-content: center;
}
.back-to-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.back-to-top svg { width: 22px; height: 22px; }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .services-grid { grid-template-columns: repeat(3, 1fr); }
    .case-grid { grid-template-columns: repeat(3, 1fr); }
    .adv-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
    .nav {
        position: fixed;
        top: 88px; left: 0; right: 0;
        flex-direction: column;
        background: var(--white);
        padding: 20px;
        box-shadow: var(--shadow-md);
        transform: translateY(-120%);
        transition: var(--transition);
        gap: 4px;
    }
    .nav.open { transform: translateY(0); }
    .nav-toggle { display: flex; }
    .nav-toggle.active span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
    .nav-toggle.active span:nth-child(2) { opacity: 0; }
    .nav-toggle.active span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

    .hero-title { font-size: 36px; }
    .hero-subtitle { font-size: 16px; }
    .hero-stats { gap: 24px; }
    .stat-num { font-size: 32px; }

    .section { padding: 64px 0; }
    .section-title { font-size: 28px; }

    .about-grid, .contact-grid { grid-template-columns: 1fr; gap: 40px; }
    .about-img-sub { width: 160px; right: 10px; bottom: -20px; }

    .services-grid { grid-template-columns: repeat(2, 1fr); }
    .case-grid { grid-template-columns: repeat(2, 1fr); }
    .products-grid { grid-template-columns: 1fr; }
    .product-card { flex-direction: column; }
    .product-img { width: 100%; height: 200px; }

    .adv-grid { grid-template-columns: 1fr; }
    .footer-inner { grid-template-columns: 1fr; gap: 32px; }
    .hero-actions { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 480px) {
    .services-grid { grid-template-columns: 1fr; }
    .case-grid { grid-template-columns: 1fr; }
    .hero-title { font-size: 28px; }
    .about-info { grid-template-columns: 1fr; }
}

/* ===== App Store support and privacy pages ===== */
.legal-page { background: var(--gray-100); min-height: 100vh; }
.legal-hero {
    padding: 150px 0 76px;
    background: linear-gradient(135deg, #0f1e3d 0%, #1e6fff 100%);
    color: var(--white);
}
.legal-hero .section-tag { color: var(--accent); }
.legal-hero h1 { font-size: 42px; font-weight: 800; margin-bottom: 14px; }
.legal-hero p { max-width: 720px; color: rgba(255,255,255,.82); font-size: 17px; }
.legal-content { max-width: 920px; margin: -34px auto 80px; position: relative; }
.legal-card {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    padding: 52px 56px;
}
.legal-card h2 { color: var(--dark); font-size: 24px; margin: 38px 0 14px; }
.legal-card h2:first-child { margin-top: 0; }
.legal-card h3 { color: var(--dark); font-size: 18px; margin: 26px 0 10px; }
.legal-card p, .legal-card li { color: var(--gray-700); line-height: 1.9; }
.legal-card p { margin-bottom: 14px; }
.legal-card ul { padding-left: 22px; margin: 0 0 16px; }
.legal-card a { color: var(--primary); font-weight: 600; }
.legal-meta { color: var(--gray-500) !important; font-size: 14px; padding-bottom: 24px; border-bottom: 1px solid var(--gray-300); }
.support-actions { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; margin: 28px 0; }
.support-action { display: block; padding: 24px; background: var(--gray-100); border-radius: 12px; transition: var(--transition); }
.support-action:hover { background: rgba(30,111,255,.08); transform: translateY(-3px); }
.support-action strong { display: block; color: var(--dark); font-size: 17px; margin-bottom: 6px; }
.support-action span { color: var(--gray-500); font-size: 14px; }
.legal-nav { display: flex; gap: 22px; align-items: center; }
.legal-nav a { color: var(--gray-700); font-weight: 500; }
.legal-nav a:hover { color: var(--primary); }
@media (max-width: 768px) {
    .legal-hero { padding: 124px 0 60px; }
    .legal-hero h1 { font-size: 30px; }
    .legal-content { margin: -24px 20px 48px; }
    .legal-card { padding: 32px 24px; }
    .legal-card h2 { font-size: 21px; }
    .support-actions { grid-template-columns: 1fr; }
    .legal-nav { display: none; }
}