/* ===== Site 1: Corporate Blue Theme ===== */
:root {
  --primary: #1565c0;
  --primary-dark: #0d47a1;
  --primary-light: #42a5f5;
  --accent: #00bcd4;
  --bg: #f0f4f8;
  --card-bg: #ffffff;
  --text: #1a2332;
  --text-secondary: #5a6a7a;
  --border: #d0d8e4;
  --shadow: rgba(21, 101, 192, 0.12);
  --radius: 12px;
  --nav-bg: rgba(255, 255, 255, 0.95);
}

* { 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", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

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

/* Navigation */
header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
nav {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  height: 64px;
}
.logo {
  font-size: 22px;
  font-weight: 800;
  color: var(--primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}
.nav-links {
  display: flex;
  list-style: none;
  gap: 4px;
}
.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 500;
  padding: 8px 18px;
  border-radius: 20px;
  transition: all 0.3s ease;
}
.nav-links a:hover {
  color: var(--primary);
  background: rgba(21, 101, 192, 0.08);
}
.nav-links a.active {
  color: #fff;
  background: var(--primary);
}

/* Hero */
.hero {
  padding: 140px 24px 100px;
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--accent) 100%);
  color: #fff;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -50%; right: -20%;
  width: 600px; height: 600px;
  background: rgba(255,255,255,0.05);
  border-radius: 50%;
}
.hero h1 {
  font-size: 48px;
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -1px;
}
.hero-subtitle {
  font-size: 20px;
  opacity: 0.9;
  max-width: 640px;
  margin: 0 auto 40px;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: #fff;
  color: var(--primary);
  padding: 16px 40px;
  border-radius: 50px;
  font-size: 17px;
  font-weight: 700;
  border: none;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 8px 30px rgba(0,0,0,0.2);
}
.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.3);
}
.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: #fff;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 15px;
  font-weight: 600;
  border: 2px solid rgba(255,255,255,0.4);
  cursor: pointer;
  transition: all 0.3s ease;
  margin-left: 12px;
}
.btn-secondary:hover {
  background: rgba(255,255,255,0.15);
  border-color: #fff;
}

/* Sections */
main { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section {
  padding: 80px 0;
}
.section-title {
  text-align: center;
  margin-bottom: 60px;
}
.section-title h2 {
  font-size: 36px;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 12px;
}
.section-title p {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* Feature Cards */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 24px;
  margin-bottom: 40px;
}
.feature-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 36px 30px;
  box-shadow: 0 4px 20px var(--shadow);
  transition: all 0.3s ease;
  border: 1px solid var(--border);
}
.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 40px var(--shadow);
}
.feature-icon {
  width: 56px; height: 56px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}
.feature-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
}
.feature-card p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Platform Download */
.platform-section {
  background: linear-gradient(180deg, var(--card-bg) 0%, var(--bg) 100%);
  border-radius: 24px;
  padding: 60px 40px;
  margin: 40px 0;
  border: 1px solid var(--border);
}
.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-top: 40px;
}
.platform-card {
  text-align: center;
  padding: 32px 24px;
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: all 0.3s ease;
}
.platform-card:hover {
  border-color: var(--primary-light);
  box-shadow: 0 8px 24px var(--shadow);
}
.platform-card .os-icon {
  width: 64px; height: 64px;
  margin: 0 auto 16px;
  background: var(--bg);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.platform-card h4 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 6px;
}
.platform-card p {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 16px;
}
.platform-card .dl-btn {
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  background: var(--primary);
  color: #fff;
  transition: all 0.3s ease;
}
.platform-card .dl-btn:hover {
  background: var(--primary-dark);
}

/* Detailed Features */
.detail-feature {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  margin-bottom: 80px;
}
.detail-feature:nth-child(even) { direction: rtl; }
.detail-feature:nth-child(even) > * { direction: ltr; }
.detail-feature h3 {
  font-size: 28px;
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--text);
}
.detail-feature p {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 12px;
}
.detail-img {
  background: linear-gradient(135deg, var(--primary-light), var(--accent));
  border-radius: var(--radius);
  height: 280px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
  font-weight: 600;
}

/* Reviews */
.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}
.review-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 30px;
  border: 1px solid var(--border);
}
.review-stars {
  color: #ffc107;
  font-size: 18px;
  margin-bottom: 12px;
}
.review-card p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}
.review-author {
  font-weight: 700;
  font-size: 14px;
  color: var(--text);
}

/* Stats */
.stats-section {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  border-radius: 24px;
  padding: 60px 40px;
  margin: 60px 0;
  color: #fff;
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  text-align: center;
}
.stat-number {
  font-size: 42px;
  font-weight: 800;
  margin-bottom: 8px;
}
.stat-label {
  font-size: 15px;
  opacity: 0.85;
}

/* Comparison Table */
.compare-section {
  margin: 60px 0;
}
.compare-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 4px 20px var(--shadow);
  border: 1px solid var(--border);
}
.compare-table th, .compare-table td {
  padding: 18px 24px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.compare-table th {
  background: var(--primary);
  color: #fff;
  font-weight: 600;
  font-size: 15px;
}
.compare-table td {
  font-size: 15px;
  color: var(--text);
}
.compare-table tr:last-child td { border-bottom: none; }
.check { color: #4caf50; font-weight: 700; }
.cross { color: #f44336; }
.highlight { background: rgba(21, 101, 192, 0.05); }

/* FAQ */
.faq-section { margin: 60px 0; }
.faq-item {
  background: var(--card-bg);
  border-radius: var(--radius);
  margin-bottom: 16px;
  border: 1px solid var(--border);
  overflow: hidden;
}
.faq-question {
  padding: 22px 28px;
  font-size: 17px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background 0.3s;
}
.faq-question:hover { background: rgba(21, 101, 192, 0.04); }
.faq-answer {
  padding: 0 28px 24px;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  display: none;
}
.faq-item.open .faq-answer { display: block; }
.faq-toggle {
  width: 24px; height: 24px;
  transition: transform 0.3s;
  color: var(--primary);
}
.faq-item.open .faq-toggle { transform: rotate(45deg); }

/* CTA Section */
.cta-section {
  background: linear-gradient(135deg, var(--primary-dark), var(--accent));
  border-radius: 24px;
  padding: 80px 40px;
  text-align: center;
  color: #fff;
  margin: 60px 0;
}
.cta-section h2 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 16px;
}
.cta-section p {
  font-size: 18px;
  opacity: 0.9;
  margin-bottom: 32px;
}

/* Footer */
footer {
  background: var(--text);
  color: rgba(255,255,255,0.7);
  padding: 40px 24px;
  text-align: center;
  font-size: 14px;
  margin-top: 80px;
}
footer p { margin-bottom: 6px; }

/* Download Page Styles */
.dl-hero {
  padding: 120px 24px 60px;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  text-align: center;
}
.dl-hero h1 { font-size: 40px; font-weight: 800; margin-bottom: 12px; }
.dl-hero p { font-size: 18px; opacity: 0.9; }

.dl-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 24px;
}

/* Windows Download Card */
.win-dl-card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 48px;
  box-shadow: 0 8px 40px var(--shadow);
  border: 1px solid var(--border);
  text-align: center;
  margin-bottom: 48px;
}
.win-dl-card .win-icon {
  width: 80px; height: 80px;
  background: linear-gradient(135deg, #00a4ef, #0078d4);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 24px;
}
.win-dl-card h2 { font-size: 28px; font-weight: 800; margin-bottom: 8px; }
.win-dl-card .version-info {
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 24px;
}
.win-dl-card .dl-btn-large {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  padding: 20px 56px;
  border-radius: 50px;
  font-size: 18px;
  font-weight: 700;
  border: none;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 8px 30px var(--shadow);
}
.win-dl-card .dl-btn-large:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 40px rgba(21, 101, 192, 0.3);
}

/* Install Steps */
.steps-section { margin: 60px 0; }
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
  margin-top: 40px;
}
.step-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  border: 1px solid var(--border);
  position: relative;
}
.step-num {
  width: 44px; height: 44px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 18px;
  margin: 0 auto 16px;
}
.step-card h4 { font-size: 17px; font-weight: 700; margin-bottom: 10px; }
.step-card p { font-size: 14px; color: var(--text-secondary); }

/* Requirements */
.req-section { margin: 60px 0; }
.req-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 32px;
}
.req-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 28px;
  border: 1px solid var(--border);
}
.req-card h4 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.req-card ul { list-style: none; }
.req-card li {
  font-size: 14px;
  color: var(--text-secondary);
  padding: 6px 0;
  border-bottom: 1px solid rgba(208, 216, 228, 0.5);
}
.req-card li:last-child { border-bottom: none; }

/* Changelog */
.changelog { margin: 60px 0; }
.changelog-item {
  display: flex;
  gap: 24px;
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
}
.changelog-version {
  min-width: 100px;
  font-weight: 800;
  color: var(--primary);
  font-size: 16px;
}
.changelog-date {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}
.changelog-list { list-style: none; }
.changelog-list li {
  font-size: 15px;
  color: var(--text-secondary);
  padding: 4px 0;
  padding-left: 16px;
  position: relative;
}
.changelog-list li::before {
  content: '>';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* Safety */
.safety-box {
  background: linear-gradient(135deg, #e8f5e9, #e3f2fd);
  border-radius: var(--radius);
  padding: 32px;
  margin: 40px 0;
  border: 1px solid #c8e6c9;
}
.safety-box h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.safety-box p { font-size: 15px; color: var(--text-secondary); line-height: 1.7; }

/* zh-cn page */
.article-content {
  max-width: 900px;
  margin: 0 auto;
  padding: 60px 24px;
}
.article-content h2 {
  font-size: 30px;
  font-weight: 800;
  margin: 48px 0 20px;
  color: var(--text);
}
.article-content h3 {
  font-size: 22px;
  font-weight: 700;
  margin: 32px 0 14px;
  color: var(--primary-dark);
}
.article-content p {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.9;
  margin-bottom: 16px;
}
.article-content ul {
  margin: 16px 0 16px 24px;
  color: var(--text-secondary);
}
.article-content li { margin-bottom: 10px; line-height: 1.7; }
.article-content strong { color: var(--text); }

.tip-box {
  background: rgba(21, 101, 192, 0.06);
  border-left: 4px solid var(--primary);
  border-radius: 0 8px 8px 0;
  padding: 24px;
  margin: 28px 0;
}
.tip-box h4 { font-size: 17px; font-weight: 700; margin-bottom: 10px; }
.tip-box p { font-size: 15px; margin-bottom: 0; }

@media (max-width: 768px) {
  .hero h1 { font-size: 32px; }
  .detail-feature { grid-template-columns: 1fr; gap: 30px; }
  .detail-feature:nth-child(even) { direction: ltr; }
  .nav-links { display: none; }
  .feature-grid { grid-template-columns: 1fr; }
  .platform-grid { grid-template-columns: 1fr 1fr; }
}