/* 飞书官网 - 全局样式 */
/* SEO优化：语义化CSS，支持响应式 */

/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    color: #1F2329; line-height: 1.6; background: #fff;
}
a { color: #3370FF; text-decoration: none; transition: color 0.2s ease-out; }
a:hover { color: #245bdb; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { font-weight: 600; line-height: 1.3; color: #1F2329; }
h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
p { margin-bottom: 1rem; }

/* === Layout === */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section { padding: 80px 0; }
.section-alt { background: #f7f8fa; }
.text-center { text-align: center; }

/* === Header / Navigation === */
.site-header {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(255,255,255,0.95); backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    transition: box-shadow 0.3s ease-out;
}
.site-header:hover { box-shadow: 0 2px 12px rgba(0,0,0,0.08); }
.header-inner {
    display: flex; align-items: center; justify-content: space-between;
    max-width: 1200px; margin: 0 auto; padding: 0 24px; height: 64px;
}
.logo { display: flex; align-items: center; gap: 8px; font-size: 1.25rem; font-weight: 700; color: #1F2329; }
.logo img { width: 32px; height: 32px; }
.nav-menu { display: flex; align-items: center; gap: 32px; }
.nav-menu a { color: #1F2329; font-size: 0.95rem; font-weight: 500; padding: 8px 0; position: relative; }
.nav-menu a:hover, .nav-menu a.active { color: #3370FF; }
.nav-menu a.active::after {
    content: ''; position: absolute; bottom: 0; left: 0; right: 0;
    height: 2px; background: #3370FF; border-radius: 1px;
}
.header-actions { display: flex; align-items: center; gap: 12px; }

/* === Buttons === */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 10px 24px; border-radius: 8px; font-size: 0.95rem; font-weight: 500;
    transition: all 0.2s ease-out; cursor: pointer; min-height: 44px; min-width: 44px;
    text-align: center; line-height: 1.4;
}
.btn-primary { background: #3370FF; color: #fff; border: 1px solid #3370FF; }
.btn-primary:hover { background: #245bdb; color: #fff; transform: translateY(-1px); box-shadow: 0 4px 12px rgba(51,112,255,0.3); }
.btn-outline { background: #fff; color: #3370FF; border: 1px solid #3370FF; }
.btn-outline:hover { background: #f0f5ff; color: #3370FF; transform: translateY(-1px); }
.btn-large { padding: 14px 36px; font-size: 1.1rem; border-radius: 10px; }
.btn-white { background: #fff; color: #3370FF; border: 1px solid #fff; }
.btn-white:hover { background: #f0f5ff; color: #3370FF; }

/* === Hero Section === */
.hero {
    padding: 140px 0 80px; background: linear-gradient(135deg, #f0f5ff 0%, #e8f4f8 50%, #f7f8fa 100%);
    min-height: 600px; display: flex; align-items: center;
}
.hero-inner { display: flex; align-items: center; gap: 60px; }
.hero-content { flex: 1; }
.hero-content h1 { font-size: 3rem; margin-bottom: 16px; line-height: 1.2; }
.hero-content h1 span { color: #3370FF; }
.hero-content .subtitle { font-size: 1.2rem; color: #646a73; margin-bottom: 32px; line-height: 1.8; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-visual { flex: 1; display: flex; justify-content: center; }
.hero-visual-img {
    width: 100%; max-width: 520px; border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.1);
    background: #fff; padding: 20px;
}
.hero-visual-img .mock-ui {
    width: 100%; aspect-ratio: 16/10; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px; display: flex; align-items: center; justify-content: center;
    color: #fff; font-size: 1.2rem; font-weight: 500;
}

/* === Feature Cards === */
.features-grid {
    display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.feature-card {
    background: #fff; border-radius: 16px; padding: 32px;
    border: 1px solid #e5e6eb; transition: all 0.3s ease-out;
}
.feature-card:hover {
    transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0,0,0,0.08);
    border-color: #3370FF;
}
.feature-icon {
    width: 56px; height: 56px; border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.5rem; margin-bottom: 16px;
}
.feature-icon.blue { background: #e8f0ff; color: #3370FF; }
.feature-icon.green { background: #e8f8f0; color: #34c759; }
.feature-icon.purple { background: #f0e8ff; color: #7c5cfc; }
.feature-icon.orange { background: #fff3e8; color: #ff9500; }
.feature-icon.red { background: #ffe8e8; color: #ff3b30; }
.feature-icon.teal { background: #e8f8f6; color: #00b4d8; }
.feature-card h3 { font-size: 1.2rem; margin-bottom: 8px; }
.feature-card p { color: #646a73; font-size: 0.95rem; margin-bottom: 12px; }
.feature-card .learn-more { color: #3370FF; font-size: 0.9rem; font-weight: 500; }
.feature-card .learn-more:hover { text-decoration: underline; }

/* === Section Headers === */
.section-header { text-align: center; margin-bottom: 48px; }
.section-header h2 { font-size: 2rem; margin-bottom: 12px; }
.section-header p { color: #646a73; font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

/* === Collaboration Demo === */
.collab-demo {
    background: #f7f8fa; border-radius: 20px; padding: 48px;
    display: flex; align-items: center; gap: 48px;
}
.collab-content { flex: 1; }
.collab-content h2 { margin-bottom: 16px; }
.collab-content p { color: #646a73; margin-bottom: 24px; }
.collab-visual { flex: 1; }
.collab-visual .mock-screen {
    width: 100%; aspect-ratio: 16/10; background: #fff;
    border-radius: 12px; border: 1px solid #e5e6eb;
    box-shadow: 0 8px 24px rgba(0,0,0,0.06);
    display: flex; align-items: center; justify-content: center;
    color: #646a73; font-size: 1rem;
}

/* === Solution Tabs === */
.solution-tabs { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 32px; justify-content: center; }
.solution-tab {
    padding: 10px 24px; border-radius: 24px; background: #f7f8fa;
    color: #646a73; font-weight: 500; transition: all 0.2s ease-out;
}
.solution-tab:hover, .solution-tab.active { background: #3370FF; color: #fff; }
.solution-content { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.solution-text h3 { margin-bottom: 12px; }
.solution-text p { color: #646a73; margin-bottom: 16px; }
.solution-list { margin-bottom: 24px; }
.solution-list li {
    padding: 8px 0; padding-left: 24px; position: relative; color: #1F2329;
}
.solution-list li::before {
    content: '✓'; position: absolute; left: 0; color: #3370FF; font-weight: 700;
}

/* === Cases / Testimonials === */
.logo-wall {
    display: flex; flex-wrap: wrap; justify-content: center; gap: 32px;
    align-items: center; margin-bottom: 48px; padding: 24px 0;
}
.logo-wall .client-logo {
    width: 120px; height: 48px; background: #f7f8fa; border-radius: 8px;
    display: flex; align-items: center; justify-content: center;
    color: #8f959e; font-size: 0.85rem; font-weight: 500;
    filter: grayscale(100%); transition: all 0.3s ease-out;
}
.logo-wall .client-logo:hover { filter: grayscale(0%); color: #3370FF; background: #e8f0ff; }
.cases-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.case-card {
    background: #fff; border-radius: 16px; overflow: hidden;
    border: 1px solid #e5e6eb; transition: all 0.3s ease-out;
}
.case-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0,0,0,0.08); }
.case-card-img {
    height: 180px; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex; align-items: center; justify-content: center; color: #fff; font-size: 1.2rem;
}
.case-card-body { padding: 24px; }
.case-card-body h4 { margin-bottom: 8px; }
.case-card-body p { color: #646a73; font-size: 0.9rem; margin-bottom: 12px; }
.case-card-body .stat { color: #3370FF; font-weight: 700; font-size: 1.1rem; }

/* === Security === */
.security-badges {
    display: flex; flex-wrap: wrap; justify-content: center; gap: 24px;
}
.security-badge {
    display: flex; flex-direction: column; align-items: center; gap: 8px;
    padding: 24px 32px; background: #fff; border-radius: 12px;
    border: 1px solid #e5e6eb; transition: all 0.2s ease-out;
}
.security-badge:hover { border-color: #3370FF; box-shadow: 0 4px 12px rgba(51,112,255,0.1); }
.security-badge .badge-icon { font-size: 2rem; }
.security-badge .badge-text { font-size: 0.85rem; color: #646a73; font-weight: 500; }

/* === Integration === */
.integration-visual {
    display: flex; justify-content: center; align-items: center;
    position: relative; padding: 48px 0;
}
.integration-center {
    width: 80px; height: 80px; background: #3370FF; border-radius: 20px;
    display: flex; align-items: center; justify-content: center;
    color: #fff; font-size: 1.5rem; font-weight: 700; z-index: 2;
}
.integration-orbit {
    position: absolute; display: flex; gap: 24px; flex-wrap: wrap;
    justify-content: center;
}
.integration-item {
    width: 56px; height: 56px; background: #fff; border-radius: 12px;
    border: 1px solid #e5e6eb; display: flex; align-items: center;
    justify-content: center; font-size: 0.7rem; color: #646a73;
    transition: all 0.2s ease-out;
}
.integration-item:hover { border-color: #3370FF; transform: scale(1.1); }

/* === Pricing === */
.pricing-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.pricing-card {
    background: #fff; border-radius: 16px; padding: 36px;
    border: 1px solid #e5e6eb; transition: all 0.3s ease-out;
    position: relative;
}
.pricing-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0,0,0,0.08); }
.pricing-card.featured { border-color: #3370FF; box-shadow: 0 8px 24px rgba(51,112,255,0.15); }
.pricing-card.featured::before {
    content: '推荐'; position: absolute; top: -12px; right: 24px;
    background: #3370FF; color: #fff; padding: 4px 16px; border-radius: 12px;
    font-size: 0.8rem; font-weight: 500;
}
.pricing-card h3 { margin-bottom: 8px; }
.pricing-card .price { font-size: 2rem; font-weight: 700; color: #1F2329; margin-bottom: 4px; }
.pricing-card .price-note { color: #8f959e; font-size: 0.85rem; margin-bottom: 24px; }
.pricing-card .features-list { margin-bottom: 24px; }
.pricing-card .features-list li {
    padding: 8px 0; padding-left: 24px; position: relative;
    color: #1F2329; font-size: 0.9rem;
}
.pricing-card .features-list li::before {
    content: '✓'; position: absolute; left: 0; color: #34c759; font-weight: 700;
}

/* === FAQ === */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    border: 1px solid #e5e6eb; border-radius: 12px; margin-bottom: 12px;
    overflow: hidden; transition: all 0.2s ease-out;
}
.faq-item:hover { border-color: #3370FF; }
.faq-question {
    padding: 20px 24px; font-weight: 600; font-size: 1rem;
    background: #fff; display: flex; align-items: center; gap: 12px;
}
.faq-question::before { content: 'Q'; color: #3370FF; font-weight: 700; font-size: 1.1rem; }
.faq-answer {
    padding: 0 24px 20px 48px; color: #646a73; font-size: 0.95rem; line-height: 1.8;
}
.faq-answer ol { padding-left: 20px; list-style: decimal; }
.faq-answer ol li { padding: 4px 0; }

/* === Bottom CTA === */
.bottom-cta {
    background: linear-gradient(135deg, #3370FF 0%, #245bdb 100%);
    padding: 80px 0; text-align: center; color: #fff;
}
.bottom-cta h2 { color: #fff; font-size: 2.2rem; margin-bottom: 12px; }
.bottom-cta p { color: rgba(255,255,255,0.85); font-size: 1.1rem; margin-bottom: 32px; }
.bottom-cta .btn-white { margin-right: 12px; }
.bottom-cta .contact-link { color: rgba(255,255,255,0.8); display: block; margin-top: 16px; }
.bottom-cta .contact-link:hover { color: #fff; }

/* === Footer === */
.site-footer { background: #1F2329; color: #8f959e; padding: 60px 0 30px; }
.footer-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px;
    margin-bottom: 40px;
}
.footer-col h4 { color: #fff; font-size: 1rem; margin-bottom: 16px; }
.footer-col a { display: block; color: #8f959e; font-size: 0.9rem; padding: 4px 0; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1); padding-top: 24px;
    display: flex; justify-content: space-between; align-items: center;
    flex-wrap: wrap; gap: 16px;
}
.footer-bottom p { font-size: 0.85rem; margin: 0; }
.footer-social { display: flex; gap: 16px; }
.footer-social a {
    width: 36px; height: 36px; border-radius: 50%; background: rgba(255,255,255,0.1);
    display: flex; align-items: center; justify-content: center;
    color: #8f959e; font-size: 0.8rem; transition: all 0.2s ease-out;
}
.footer-social a:hover { background: #3370FF; color: #fff; }

/* === Page Hero (Sub pages) === */
.page-hero {
    padding: 120px 0 60px; background: linear-gradient(135deg, #f0f5ff 0%, #f7f8fa 100%);
    text-align: center;
}
.page-hero h1 { font-size: 2.5rem; margin-bottom: 12px; }
.page-hero p { color: #646a73; font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

/* === Breadcrumb === */
.breadcrumb { padding: 16px 0; font-size: 0.85rem; color: #8f959e; }
.breadcrumb a { color: #8f959e; }
.breadcrumb a:hover { color: #3370FF; }
.breadcrumb span { margin: 0 8px; }

/* === Help Center === */
.help-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.help-card {
    background: #fff; border-radius: 16px; padding: 32px;
    border: 1px solid #e5e6eb; text-align: center;
    transition: all 0.3s ease-out;
}
.help-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0,0,0,0.08); }
.help-card .help-icon { font-size: 2.5rem; margin-bottom: 16px; }
.help-card h3 { margin-bottom: 8px; }
.help-card p { color: #646a73; font-size: 0.9rem; }

/* === Download Page === */
.download-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; max-width: 800px; margin: 0 auto; }
.download-card {
    background: #fff; border-radius: 16px; padding: 32px;
    border: 1px solid #e5e6eb; text-align: center;
    transition: all 0.3s ease-out;
}
.download-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0,0,0,0.08); }
.download-card .dl-icon { font-size: 3rem; margin-bottom: 16px; }
.download-card h3 { margin-bottom: 8px; }
.download-card p { color: #646a73; font-size: 0.9rem; margin-bottom: 16px; }

/* === About Page === */
.about-content { max-width: 800px; margin: 0 auto; }
.about-content p { font-size: 1.05rem; line-height: 1.8; color: #4e5969; margin-bottom: 16px; }
.stats-row { display: flex; justify-content: center; gap: 48px; flex-wrap: wrap; margin: 48px 0; }
.stat-item { text-align: center; }
.stat-item .stat-number { font-size: 2.5rem; font-weight: 700; color: #3370FF; }
.stat-item .stat-label { color: #646a73; font-size: 0.9rem; }

/* === Mobile Menu === */
.mobile-menu-btn {
    display: none; width: 44px; height: 44px; border: none; background: none;
    cursor: pointer; flex-direction: column; align-items: center; justify-content: center; gap: 5px;
}
.mobile-menu-btn span {
    display: block; width: 22px; height: 2px; background: #1F2329;
    border-radius: 1px; transition: all 0.3s ease-out;
}

/* === Responsive === */
@media (max-width: 1279px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .cases-grid { grid-template-columns: repeat(2, 1fr); }
    .pricing-grid { grid-template-columns: repeat(2, 1fr); }
    .hero-inner { flex-direction: column; text-align: center; }
    .hero-actions { justify-content: center; }
    .collab-demo { flex-direction: column; }
    .solution-content { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 767px) {
    h1 { font-size: 1.8rem; }
    h2 { font-size: 1.5rem; }
    .section { padding: 48px 0; }
    .hero { padding: 100px 0 48px; min-height: auto; }
    .hero-content h1 { font-size: 2rem; }
    .features-grid { grid-template-columns: 1fr; }
    .cases-grid { grid-template-columns: 1fr; }
    .pricing-grid { grid-template-columns: 1fr; }
    .help-grid { grid-template-columns: 1fr; }
    .download-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .nav-menu { display: none; }
    .mobile-menu-btn { display: flex; }
    .header-actions .btn-outline { display: none; }
    .collab-demo { padding: 24px; }
    .stats-row { gap: 24px; }
    .footer-bottom { flex-direction: column; text-align: center; }
}

/* === Animations (CSS only) === */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-in { animation: fadeInUp 0.6s ease-out forwards; }
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }

/* === Accessibility === */
:focus-visible { outline: 2px solid #3370FF; outline-offset: 2px; }
.sr-only {
    position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
    overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}