/* Site 1 - Clean Official Style: White + Chrome Blue, "Safe Download Center" feel */
:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --secondary: #34a853;
  --accent: #fbbc04;
  --danger: #ea4335;
  --bg: #ffffff;
  --bg-alt: #f8f9fa;
  --bg-hero: linear-gradient(135deg, #e8f0fe 0%, #ffffff 100%);
  --text: #202124;
  --text-light: #5f6368;
  --border: #dadce0;
  --card-bg: #ffffff;
  --shadow: 0 1px 2px rgba(60,64,67,0.1), 0 2px 6px rgba(60,64,67,0.08);
  --shadow-hover: 0 4px 12px rgba(60,64,67,0.15);
  --radius: 8px;
  --radius-lg: 12px;
  --max-width: 1200px;
  --font: 'Segoe UI', 'Microsoft YaHei', 'PingFang SC', sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

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

/* Header & Nav */
header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

nav {
  max-width: var(--max-width);
  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: 20px;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}

.nav-brand svg { width: 32px; height: 32px; }

.nav-links {
  display: flex;
  list-style: none;
  gap: 4px;
}

.nav-links a {
  display: block;
  padding: 8px 18px;
  text-decoration: none;
  color: var(--text-light);
  font-size: 15px;
  font-weight: 500;
  border-radius: 20px;
  transition: all 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  background: #e8f0fe;
}

/* Hero */
.hero {
  background: var(--bg-hero);
  padding: 80px 24px;
  text-align: center;
}

.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 16px;
  line-height: 1.2;
}

.hero .subtitle {
  font-size: 20px;
  color: var(--text-light);
  max-width: 640px;
  margin: 0 auto 32px;
}

.hero-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 32px;
  font-size: 14px;
  color: var(--text-light);
}

.hero-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 36px;
  background: var(--primary);
  color: #fff;
  font-size: 17px;
  font-weight: 600;
  border: none;
  border-radius: 28px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s;
  box-shadow: 0 2px 8px rgba(26,115,232,0.3);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(26,115,232,0.35);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  background: transparent;
  color: var(--primary);
  font-size: 15px;
  font-weight: 500;
  border: 1.5px solid var(--primary);
  border-radius: 24px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s;
}

.btn-secondary:hover {
  background: var(--primary);
  color: #fff;
}

/* Sections */
.section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 72px 24px;
}

.section-title {
  font-size: 32px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
  color: var(--text);
}

.section-desc {
  text-align: center;
  color: var(--text-light);
  font-size: 17px;
  margin-bottom: 48px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.bg-alt { background: var(--bg-alt); }

/* Feature Cards */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all 0.25s;
}

.feature-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.feature-card .icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
  padding: 10px;
  background: #e8f0fe;
  border-radius: var(--radius);
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.7;
}

/* Platform Cards */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
}

.platform-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  text-align: center;
  transition: all 0.25s;
}

.platform-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.platform-card .p-icon {
  width: 44px;
  height: 44px;
  margin: 0 auto 12px;
}

.platform-card h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.platform-card p {
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 14px;
}

/* Content Sections */
.content-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
  margin-bottom: 64px;
}

.content-row:last-child { margin-bottom: 0; }

.content-row.reverse { direction: rtl; }
.content-row.reverse > * { direction: ltr; }

.content-row h3 {
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text);
}

.content-row p {
  font-size: 16px;
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 12px;
}

.content-visual {
  background: linear-gradient(135deg, #e8f0fe, #d2e3fc);
  border-radius: var(--radius-lg);
  padding: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 240px;
}

.content-visual svg {
  width: 120px;
  height: 120px;
}

/* Stats */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  text-align: center;
}

.stat-item .stat-num {
  font-size: 40px;
  font-weight: 800;
  color: var(--primary);
  display: block;
}

.stat-item .stat-label {
  font-size: 15px;
  color: var(--text-light);
  margin-top: 6px;
}

/* Reviews */
.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.review-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.review-card .stars {
  color: var(--accent);
  font-size: 18px;
  margin-bottom: 10px;
}

.review-card .review-text {
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.7;
  margin-bottom: 14px;
}

.review-card .reviewer {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

/* Comparison Table */
.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
}

.compare-table th,
.compare-table td {
  padding: 14px 18px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.compare-table th {
  background: var(--bg-alt);
  font-weight: 600;
  color: var(--text);
}

.compare-table td { color: var(--text-light); }

.compare-table .check { color: var(--secondary); font-weight: 700; }

.compare-table .cross { color: var(--danger); }

/* Scenarios */
.scenario-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.scenario-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  text-align: center;
}

.scenario-card .sc-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 14px;
  padding: 12px;
  background: #e8f0fe;
  border-radius: 50%;
}

.scenario-card h4 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
}

.scenario-card p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.6;
}

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }

.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 22px 0;
}

.faq-item h4 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text);
}

.faq-item p {
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.7;
}

/* Download Page Specific */
.download-hero {
  background: linear-gradient(135deg, #1a73e8 0%, #4285f4 100%);
  color: #fff;
  padding: 64px 24px;
  text-align: center;
}

.download-hero h1 {
  font-size: 40px;
  font-weight: 700;
  margin-bottom: 12px;
}

.download-hero p {
  font-size: 18px;
  opacity: 0.9;
  max-width: 560px;
  margin: 0 auto 28px;
}

.download-hero .btn-primary {
  background: #fff;
  color: var(--primary);
  box-shadow: 0 2px 12px rgba(0,0,0,0.15);
}

.download-hero .btn-primary:hover {
  background: #f8f9fa;
}

.dl-meta {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-top: 20px;
  font-size: 14px;
  opacity: 0.85;
}

/* Platform Download Cards */
.dl-platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.dl-platform-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.dl-platform-card .dl-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.dl-platform-card .dl-header svg { width: 36px; height: 36px; }

.dl-platform-card h4 {
  font-size: 18px;
  font-weight: 600;
}

.dl-platform-card .dl-info {
  font-size: 14px;
  color: var(--text-light);
  margin-bottom: 16px;
  line-height: 1.6;
}

/* Install Steps */
.steps {
  display: flex;
  gap: 24px;
  counter-reset: step;
}

.step-item {
  flex: 1;
  position: relative;
  padding-top: 48px;
}

.step-item::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 36px;
  height: 36px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 16px;
}

.step-item h4 {
  font-size: 16px;
  font-weight: 600;
  text-align: center;
  margin-bottom: 8px;
}

.step-item p {
  font-size: 14px;
  color: var(--text-light);
  text-align: center;
  line-height: 1.6;
}

/* Sys Requirements Table */
.sys-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.sys-table th,
.sys-table td {
  padding: 12px 16px;
  border: 1px solid var(--border);
  text-align: left;
}

.sys-table th {
  background: var(--bg-alt);
  font-weight: 600;
}

/* Changelog */
.changelog-item {
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
}

.changelog-item .cl-version {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}

.changelog-item .cl-date {
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 10px;
}

.changelog-item ul {
  margin-left: 20px;
  color: var(--text-light);
  font-size: 15px;
  line-height: 1.7;
}

/* Accordion FAQ */
.accordion-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 10px;
  overflow: hidden;
}

.accordion-header {
  width: 100%;
  padding: 16px 20px;
  background: var(--card-bg);
  border: none;
  font-size: 16px;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text);
}

.accordion-header::after {
  content: '+';
  font-size: 20px;
  color: var(--primary);
  transition: transform 0.2s;
}

.accordion-item.open .accordion-header::after {
  transform: rotate(45deg);
}

.accordion-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s;
}

.accordion-item.open .accordion-body {
  max-height: 500px;
}

.accordion-body > div {
  padding: 0 20px 18px;
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.7;
}

/* CTA Button (for zh-cn page) */
.cta-box {
  background: linear-gradient(135deg, #e8f0fe, #d2e3fc);
  border-radius: var(--radius-lg);
  padding: 40px;
  text-align: center;
  margin: 40px 0;
}

.cta-box h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 12px;
}

.cta-box p {
  font-size: 16px;
  color: var(--text-light);
  margin-bottom: 20px;
}

/* Article content */
.article {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 24px;
}

.article h2 {
  font-size: 28px;
  font-weight: 700;
  margin: 40px 0 16px;
  color: var(--text);
}

.article h3 {
  font-size: 21px;
  font-weight: 600;
  margin: 28px 0 12px;
  color: var(--text);
}

.article p {
  font-size: 16px;
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 14px;
}

.article ul,
.article ol {
  margin: 12px 0 12px 24px;
  color: var(--text-light);
  line-height: 1.8;
}

.article li { margin-bottom: 6px; }

/* Footer */
footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 40px 24px;
  text-align: center;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer-shield {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 16px;
  font-size: 15px;
  color: var(--secondary);
  font-weight: 600;
}

.footer-shield svg { width: 22px; height: 22px; }

.footer-copy {
  font-size: 13px;
  color: var(--text-light);
}

/* Responsive */
@media (max-width: 768px) {
  nav { padding: 0 16px; height: 56px; }
  .nav-links a { padding: 6px 12px; font-size: 14px; }
  .hero { padding: 56px 16px; }
  .hero h1 { font-size: 32px; }
  .hero .subtitle { font-size: 17px; }
  .section { padding: 48px 16px; }
  .section-title { font-size: 26px; }
  .content-row { grid-template-columns: 1fr; gap: 32px; }
  .content-row.reverse { direction: ltr; }
  .steps { flex-direction: column; }
  .feature-grid { grid-template-columns: 1fr; }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .dl-platform-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .review-grid { grid-template-columns: 1fr; }
  .scenario-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 26px; }
  .platform-grid { grid-template-columns: 1fr; }
}