/* 基础重置与变量 */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f7fa;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a6a;
    --accent: #e94560;
    --accent-hover: #d63850;
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
    --radius: 12px;
    --transition: 0.3s ease;
}
[data-theme="dark"] {
    --bg-primary: #0f0f1a;
    --bg-secondary: #1a1a2e;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0b0;
    --shadow: 0 4px 20px rgba(0,0,0,0.4);
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    transition: background var(--transition), color var(--transition);
}
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-hover); }
img, svg { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

/* 导航 */
.site-header {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(255,255,255,0.9); backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    transition: background var(--transition);
}
[data-theme="dark"] .site-header { background: rgba(15,15,26,0.9); border-bottom-color: rgba(255,255,255,0.05); }
.main-nav {
    display: flex; align-items: center; justify-content: space-between;
    max-width: 1200px; margin: 0 auto; padding: 0 20px; height: 64px;
}
.nav-links { display: flex; gap: 24px; }
.nav-links a { color: var(--text-primary); font-weight: 500; font-size: 0.95rem; padding: 8px 0; border-bottom: 2px solid transparent; transition: border-color var(--transition); }
.nav-links a:hover { border-bottom-color: var(--accent); }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle .bar { display: block; width: 24px; height: 2px; background: var(--text-primary); margin: 5px 0; transition: var(--transition); }
.dark-mode-toggle { background: none; border: none; cursor: pointer; padding: 8px; color: var(--text-primary); }
@media (max-width: 768px) {
    .nav-links { display: none; }
    .nav-toggle { display: block; }
}

/* Hero */
.hero-section {
    padding-top: 64px; min-height: 80vh; display: flex; align-items: center;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    color: #fff; position: relative; overflow: hidden;
}
.hero-slider { width: 100%; position: relative; }
.slide { display: none; padding: 80px 20px; text-align: center; }
.slide.active { display: block; animation: fadeIn 0.6s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.slide h1, .slide h2 { font-size: 3rem; font-weight: 800; margin-bottom: 16px; }
.slide p { font-size: 1.2rem; color: rgba(255,255,255,0.8); max-width: 600px; margin: 0 auto 24px; }
.hero-sub { font-size: 1rem; color: rgba(255,255,255,0.6); }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-primary, .btn-secondary {
    padding: 12px 32px; border-radius: 50px; font-weight: 600; font-size: 1rem;
    transition: all var(--transition); display: inline-block;
}
.btn-primary { background: var(--accent); color: #fff; border: 2px solid var(--accent); }
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn-secondary { background: transparent; color: #fff; border: 2px solid rgba(255,255,255,0.3); }
.btn-secondary:hover { border-color: #fff; background: rgba(255,255,255,0.1); }
.slider-controls { display: flex; align-items: center; justify-content: center; gap: 16px; margin-top: 32px; }
.slider-prev, .slider-next { background: rgba(255,255,255,0.1); border: none; color: #fff; font-size: 1.5rem; padding: 8px 16px; border-radius: 50%; cursor: pointer; transition: background var(--transition); }
.slider-prev:hover, .slider-next:hover { background: rgba(255,255,255,0.2); }
.slider-dots { display: flex; gap: 8px; }
.dot { width: 12px; height: 12px; border-radius: 50%; background: rgba(255,255,255,0.3); cursor: pointer; transition: background var(--transition); }
.dot.active { background: var(--accent); }

/* 通用section */
.section { padding: 80px 0; }
.section-header { text-align: center; margin-bottom: 48px; }
.section-header h2 { font-size: 2.2rem; font-weight: 700; margin-bottom: 12px; }
.section-desc { color: var(--text-secondary); font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

/* About */
.about-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 32px; }
.about-card { background: var(--bg-secondary); padding: 32px; border-radius: var(--radius); box-shadow: var(--shadow); transition: transform var(--transition); }
.about-card:hover { transform: translateY(-4px); }
.about-card h3 { font-size: 1.3rem; margin-bottom: 12px; color: var(--accent); }
.about-card p { margin-bottom: 12px; color: var(--text-secondary); }

/* Products */
.products-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.product-card { background: var(--bg-secondary); padding: 32px; border-radius: var(--radius); box-shadow: var(--shadow); text-align: center; transition: transform var(--transition); }
.product-card:hover { transform: translateY(-4px); }
.product-icon { margin-bottom: 16px; }
.product-card h3 { font-size: 1.3rem; margin-bottom: 12px; }
.product-card p { color: var(--text-secondary); margin-bottom: 16px; }
.product-features { text-align: left; margin-bottom: 16px; padding-left: 20px; }
.product-features li { position: relative; padding-left: 20px; margin-bottom: 8px; color: var(--text-secondary); }
.product-features li::before { content: "✓"; position: absolute; left: 0; color: var(--accent); font-weight: bold; }
.btn-text { color: var(--accent); font-weight: 600; transition: color var(--transition); }
.btn-text:hover { color: var(--accent-hover); }

/* Services */
.services-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; }
.service-card { background: var(--bg-secondary); padding: 32px; border-radius: var(--radius); box-shadow: var(--shadow); text-align: center; transition: transform var(--transition); }
.service-card:hover { transform: translateY(-4px); }
.service-icon { margin-bottom: 16px; }
.service-card h3 { font-size: 1.2rem; margin-bottom: 12px; }
.service-card p { color: var(--text-secondary); }

/* Features */
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.feature-card { background: var(--bg-secondary); padding: 32px; border-radius: var(--radius); box-shadow: var(--shadow); transition: transform var(--transition); }
.feature-card:hover { transform: translateY(-4px); }
.feature-card h3 { font-size: 1.2rem; margin-bottom: 12px; color: var(--accent); }
.feature-card p { color: var(--text-secondary); }

/* Stats */
.stats-section { background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%); color: #fff; padding: 60px 0; }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; text-align: center; }
.stat-number { display: block; font-size: 2.5rem; font-weight: 800; color: var(--accent); margin-bottom: 8px; }
.stat-label { font-size: 1rem; color: rgba(255,255,255,0.7); }
@media (max-width: 768px) { .stats-grid { grid-template-columns: repeat(2, 1fr); } }

/* Insights */
.insights-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 24px; }
.insight-card { background: var(--bg-secondary); padding: 32px; border-radius: var(--radius); box-shadow: var(--shadow); transition: transform var(--transition); }
.insight-card:hover { transform: translateY(-4px); }
.insight-card time { display: block; font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 8px; }
.insight-card h3 { font-size: 1.2rem; margin-bottom: 12px; }
.insight-card p { color: var(--text-secondary); margin-bottom: 16px; }

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { background: var(--bg-secondary); border-radius: var(--radius); margin-bottom: 12px; overflow: hidden; box-shadow: var(--shadow); }
.faq-item summary { padding: 20px 24px; font-weight: 600; cursor: pointer; position: relative; transition: background var(--transition); }
.faq-item summary:hover { background: rgba(233,69,96,0.05); }
.faq-item[open] summary { border-bottom: 1px solid rgba(0,0,0,0.05); }
.faq-item p { padding: 20px 24px; color: var(--text-secondary); }

/* HowTo */
.howto-steps { max-width: 700px; margin: 0 auto; counter-reset: step; }
.howto-steps li { display: flex; align-items: flex-start; gap: 20px; margin-bottom: 24px; padding: 20px; background: var(--bg-secondary); border-radius: var(--radius); box-shadow: var(--shadow); }
.step-number { flex-shrink: 0; width: 40px; height: 40px; border-radius: 50%; background: var(--accent); color: #fff; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 1.2rem; }
.howto-steps h3 { font-size: 1.1rem; margin-bottom: 4px; }
.howto-steps p { color: var(--text-secondary); }

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
@media (max-width: 768px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-info h3, .contact-form h3 { font-size: 1.3rem; margin-bottom: 20px; }
.contact-info address p { margin-bottom: 12px; color: var(--text-secondary); }
.form-group { margin-bottom: 16px; }
.form-group label { display: block; margin-bottom: 6px; font-weight: 500; }
.form-group input, .form-group textarea { width: 100%; padding: 12px 16px; border: 1px solid rgba(0,0,0,0.1); border-radius: 8px; background: var(--bg-primary); color: var(--text-primary); transition: border-color var(--transition); }
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: var(--accent); }
[data-theme="dark"] .form-group input, [data-theme="dark"] .form-group textarea { border-color: rgba(255,255,255,0.1); }

/* Footer */
.site-footer { background: #0f0f1a; color: rgba(255,255,255,0.8); padding: 60px 0 20px; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 32px; margin-bottom: 40px; }
.footer-brand p { margin-top: 12px; font-size: 0.9rem; color: rgba(255,255,255,0.6); }
.footer-links h4, .footer-legal h4, .footer-contact h4 { color: #fff; margin-bottom: 16px; font-size: 1rem; }
.footer-links ul li, .footer-legal ul li { margin-bottom: 8px; }
.footer-links a, .footer-legal a { color: rgba(255,255,255,0.6); transition: color var(--transition); }
.footer-links a:hover, .footer-legal a:hover { color: var(--accent); }
.footer-contact address p { margin-bottom: 8px; color: rgba(255,255,255,0.6); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 20px; text-align: center; }
.footer-bottom p { font-size: 0.9rem; color: rgba(255,255,255,0.5); margin-bottom: 4px; }
.footer-bottom small { font-size: 0.8rem; }

/* Back to top */
.back-to-top { position: fixed; bottom: 30px; right: 30px; width: 48px; height: 48px; border-radius: 50%; background: var(--accent); color: #fff; border: none; cursor: pointer; display: none; align-items: center; justify-content: center; box-shadow: 0 4px 12px rgba(0,0,0,0.2); transition: all var(--transition); z-index: 999; }
.back-to-top.visible { display: flex; }
.back-to-top:hover { transform: translateY(-2px); background: var(--accent-hover); }

/* 搜索覆盖层 */
.search-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.6); backdrop-filter: blur(8px); display: none; align-items: center; justify-content: center; z-index: 2000; }
.search-overlay.active { display: flex; }
.search-modal { background: var(--bg-primary); padding: 32px; border-radius: var(--radius); width: 90%; max-width: 500px; position: relative; }
.search-modal form { display: flex; gap: 12px; }
.search-modal input { flex: 1; padding: 12px 16px; border: 1px solid rgba(0,0,0,0.1); border-radius: 8px; background: var(--bg-secondary); color: var(--text-primary); font-size: 1rem; }
.search-modal input:focus { outline: none; border-color: var(--accent); }
.search-modal button { background: var(--accent); color: #fff; border: none; padding: 12px 20px; border-radius: 8px; cursor: pointer; }
.search-close { position: absolute; top: 12px; right: 12px; background: none; border: none; font-size: 1.5rem; color: var(--text-primary); cursor: pointer; }

/* 移动端导航覆盖层 */
.mobile-nav-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); display: none; z-index: 1500; }
.mobile-nav-overlay.active { display: block; }
.mobile-nav { position: fixed; top: 0; right: -300px; width: 280px; height: 100%; background: var(--bg-primary); padding: 80px 24px 24px; transition: right 0.3s ease; box-shadow: -4px 0 20px rgba(0,0,0,0.1); }
.mobile-nav-overlay.active .mobile-nav { right: 0; }
.mobile-nav-close { position: absolute; top: 16px; right: 16px; background: none; border: none; font-size: 1.5rem; color: var(--text-primary); cursor: pointer; }
.mobile-nav ul li { margin-bottom: 16px; }
.mobile-nav ul li a { font-size: 1.1rem; color: var(--text-primary); font-weight: 500; display: block; padding: 8px 0; border-bottom: 1px solid rgba(0,0,0,0.05); }

/* 响应式 */
@media (max-width: 768px) {
    .slide h1, .slide h2 { font-size: 2rem; }
    .section { padding: 60px 0; }
    .section-header h2 { font-size: 1.8rem; }
}
@media (max-width: 480px) {
    .slide h1, .slide h2 { font-size: 1.6rem; }
    .hero-actions { flex-direction: column; align-items: center; }
    .btn-primary, .btn-secondary { width: 100%; max-width: 280px; text-align: center; }
}