/* === Site 1: Corporate Blue Theme === */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --secondary: #64748b;
  --accent: #f59e0b;
  --text: #1e293b;
  --text-light: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
  --radius: 8px;
  --radius-lg: 16px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif; color: var(--text); line-height: 1.6; background: var(--bg); }

@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

/* === Navigation === */
.nav-main { position: fixed; top: 0; left: 0; right: 0; z-index: 100; background: rgba(255,255,255,0.95); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border); }
.nav-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; height: 64px; }
.nav-brand { display: flex; align-items: center; gap: 10px; font-size: 1.25rem; font-weight: 700; color: var(--primary); text-decoration: none; }
.nav-links { display: flex; gap: 4px; list-style: none; }
.nav-links a { padding: 8px 18px; border-radius: 6px; font-size: 0.9375rem; font-weight: 500; color: var(--text-light); text-decoration: none; transition: all 0.2s; }
.nav-links a:hover { color: var(--primary); background: var(--primary-light); }
.nav-links a.active { color: var(--primary); background: var(--primary-light); }

/* === Hero === */
.hero { padding: 140px 24px 100px; background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 50%, #3b82f6 100%); color: #fff; text-align: center; }
.hero-inner { max-width: 800px; margin: 0 auto; }
.hero h1 { font-size: 3rem; font-weight: 800; line-height: 1.15; margin-bottom: 20px; letter-spacing: -0.02em; }
.hero-sub { font-size: 1.25rem; color: rgba(255,255,255,0.85); margin-bottom: 40px; line-height: 1.7; }
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 14px 32px; border-radius: var(--radius); font-size: 1rem; font-weight: 600; text-decoration: none; cursor: pointer; border: none; transition: all 0.2s; }
.btn-primary { background: #fff; color: var(--primary); }
.btn-primary:hover { background: #f1f5f9; transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-secondary { background: rgba(255,255,255,0.15); color: #fff; border: 1px solid rgba(255,255,255,0.3); }
.btn-secondary:hover { background: rgba(255,255,255,0.25); }

/* === Section Commons === */
.section { padding: 80px 24px; }
.section-alt { background: var(--bg-alt); }
.section-inner { max-width: 1200px; margin: 0 auto; }
.section-title { font-size: 2.25rem; font-weight: 700; text-align: center; margin-bottom: 16px; color: var(--text); }
.section-sub { font-size: 1.125rem; color: var(--text-light); text-align: center; margin-bottom: 56px; max-width: 640px; margin-left: auto; margin-right: auto; }

/* === Feature Cards === */
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); gap: 24px; }
.feature-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 32px; transition: all 0.25s; }
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary-light); }
.feature-icon { width: 52px; height: 52px; background: var(--primary-light); border-radius: 12px; display: flex; align-items: center; justify-content: center; margin-bottom: 20px; color: var(--primary); }
.feature-card h3 { font-size: 1.25rem; font-weight: 600; margin-bottom: 10px; color: var(--text); }
.feature-card p { color: var(--text-light); font-size: 0.9375rem; line-height: 1.7; }

/* === Download Platforms === */
.dl-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
.dl-card { background: var(--bg); border: 2px solid var(--border); border-radius: var(--radius-lg); padding: 32px 24px; text-align: center; transition: all 0.25s; }
.dl-card:hover { border-color: var(--primary); transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.dl-icon { width: 64px; height: 64px; background: var(--primary-light); border-radius: 16px; display: flex; align-items: center; justify-content: center; margin: 0 auto 16px; color: var(--primary); }
.dl-card h4 { font-size: 1.125rem; font-weight: 600; margin-bottom: 6px; }
.dl-card p { font-size: 0.875rem; color: var(--text-light); margin-bottom: 16px; }
.btn-dl { display: inline-flex; align-items: center; gap: 6px; padding: 10px 24px; background: var(--primary); color: #fff; border: none; border-radius: var(--radius); font-size: 0.9375rem; font-weight: 600; cursor: pointer; text-decoration: none; transition: all 0.2s; }
.btn-dl:hover { background: var(--primary-dark); transform: translateY(-1px); }

/* === Product Detail === */
.prod-row { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; margin-bottom: 64px; }
.prod-row:last-child { margin-bottom: 0; }
.prod-row.reverse { direction: rtl; }
.prod-row.reverse > * { direction: ltr; }
.prod-visual { background: linear-gradient(135deg, var(--primary-light), #eff6ff); border-radius: var(--radius-lg); height: 280px; display: flex; align-items: center; justify-content: center; color: var(--primary); }
.prod-text h3 { font-size: 1.75rem; font-weight: 700; margin-bottom: 16px; color: var(--text); }
.prod-text p { color: var(--text-light); line-height: 1.8; margin-bottom: 12px; }

/* === Testimonials === */
.testi-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); gap: 24px; }
.testi-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 28px; }
.testi-stars { color: var(--accent); font-size: 1.125rem; margin-bottom: 12px; letter-spacing: 2px; }
.testi-text { color: var(--text); line-height: 1.7; margin-bottom: 16px; font-size: 0.9375rem; }
.testi-author { display: flex; align-items: center; gap: 12px; }
.testi-avatar { width: 44px; height: 44px; border-radius: 50%; background: var(--primary-light); display: flex; align-items: center; justify-content: center; font-weight: 700; color: var(--primary); font-size: 0.875rem; }
.testi-name { font-weight: 600; font-size: 0.9375rem; }
.testi-role { font-size: 0.8125rem; color: var(--text-light); }

/* === Stats === */
.stats-bar { background: linear-gradient(135deg, #1e3a5f, #2563eb); padding: 60px 24px; }
.stats-grid { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 32px; text-align: center; }
.stat-num { font-size: 2.5rem; font-weight: 800; color: #fff; }
.stat-label { font-size: 0.9375rem; color: rgba(255,255,255,0.75); margin-top: 4px; }

/* === Comparison Table === */
.compare-table { width: 100%; border-collapse: collapse; background: var(--bg); border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow); }
.compare-table th { background: var(--primary); color: #fff; padding: 16px 24px; font-weight: 600; text-align: left; }
.compare-table td { padding: 14px 24px; border-bottom: 1px solid var(--border); color: var(--text); }
.compare-table tr:nth-child(even) { background: var(--bg-alt); }
.compare-table .yes { color: #16a34a; font-weight: 600; }
.compare-table .no { color: #dc2626; }

/* === FAQ === */
.faq-item { border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 12px; overflow: hidden; }
.faq-q { padding: 18px 24px; background: var(--bg); cursor: pointer; display: flex; justify-content: space-between; align-items: center; font-weight: 600; font-size: 1rem; transition: background 0.2s; }
.faq-q:hover { background: var(--bg-alt); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.faq-a-inner { padding: 0 24px 20px; color: var(--text-light); line-height: 1.8; }
.faq-item.open .faq-a { max-height: 400px; }
.faq-item.open .faq-q { color: var(--primary); }
.faq-toggle { font-size: 1.25rem; color: var(--text-light); transition: transform 0.3s; }
.faq-item.open .faq-toggle { transform: rotate(45deg); color: var(--primary); }

/* === Footer === */
.footer { background: #0f172a; color: #94a3b8; padding: 40px 24px; text-align: center; font-size: 0.875rem; }
.footer-inner { max-width: 1200px; margin: 0 auto; }
.footer p { margin-bottom: 8px; }

/* === Download Page Specific === */
.dl-hero { background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 100%); padding: 140px 24px 80px; color: #fff; }
.dl-hero-inner { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.dl-hero h1 { font-size: 2.5rem; font-weight: 800; margin-bottom: 16px; }
.dl-hero p { color: rgba(255,255,255,0.85); margin-bottom: 32px; font-size: 1.0625rem; line-height: 1.7; }
.dl-meta { display: flex; gap: 24px; flex-wrap: wrap; margin-bottom: 24px; }
.dl-meta span { display: flex; align-items: center; gap: 6px; font-size: 0.875rem; color: rgba(255,255,255,0.8); }
.dl-hero-visual { display: flex; align-items: center; justify-content: center; }
.dl-hero-box { width: 200px; height: 200px; background: rgba(255,255,255,0.1); border-radius: 24px; border: 2px solid rgba(255,255,255,0.2); display: flex; align-items: center; justify-content: center; backdrop-filter: blur(10px); }

.dl-section { padding: 60px 24px; }
.dl-section-title { font-size: 1.75rem; font-weight: 700; margin-bottom: 32px; }

.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 24px; }
.step { text-align: center; }
.step-num { width: 48px; height: 48px; background: var(--primary); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 1.125rem; margin: 0 auto 16px; }
.step h4 { font-size: 1rem; font-weight: 600; margin-bottom: 8px; }
.step p { font-size: 0.875rem; color: var(--text-light); line-height: 1.6; }

.sys-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.sys-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 24px; }
.sys-card h4 { font-size: 1.125rem; font-weight: 600; margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.sys-card ul { list-style: none; }
.sys-card li { padding: 6px 0; font-size: 0.875rem; color: var(--text-light); border-bottom: 1px solid var(--border); }
.sys-card li:last-child { border-bottom: none; }

.changelog { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; }
.chg-item { padding: 20px 24px; border-bottom: 1px solid var(--border); }
.chg-item:last-child { border-bottom: none; }
.chg-ver { display: inline-flex; align-items: center; gap: 8px; font-weight: 700; color: var(--primary); margin-bottom: 6px; }
.chg-date { font-size: 0.8125rem; color: var(--text-light); margin-left: 8px; font-weight: 400; }
.chg-list { margin: 0; padding-left: 18px; color: var(--text-light); font-size: 0.875rem; }
.chg-list li { padding: 3px 0; }

/* === zh-cn page CTA === */
.cta-bar { background: linear-gradient(135deg, #1e3a5f, #2563eb); padding: 60px 24px; text-align: center; color: #fff; }
.cta-bar h2 { font-size: 2rem; font-weight: 700; margin-bottom: 16px; }
.cta-bar p { color: rgba(255,255,255,0.85); margin-bottom: 32px; }

/* === Responsive === */
@media (max-width: 768px) {
  .hero { padding: 120px 20px 60px; }
  .hero h1 { font-size: 2rem; }
  .hero-sub { font-size: 1rem; }
  .section { padding: 48px 20px; }
  .section-title { font-size: 1.75rem; }
  .features-grid, .testi-grid { grid-template-columns: 1fr; }
  .prod-row { grid-template-columns: 1fr; gap: 32px; }
  .prod-row.reverse { direction: ltr; }
  .dl-hero-inner { grid-template-columns: 1fr; text-align: center; }
  .dl-hero-box { display: none; }
  .nav-links a { padding: 6px 12px; font-size: 0.875rem; }
}

/* === Utility === */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border-width: 0; }