/* === Site 1: Clean Official - Safe Download Center === */
:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --secondary: #34a853;
  --accent: #fbbc04;
  --danger: #ea4335;
  --bg: #ffffff;
  --bg-alt: #f8f9fa;
  --bg-section: #f1f3f4;
  --text: #202124;
  --text-secondary: #5f6368;
  --border: #dadce0;
  --shadow: 0 1px 2px rgba(60,64,67,0.1), 0 2px 6px rgba(60,64,67,0.05);
  --shadow-hover: 0 4px 12px rgba(60,64,67,0.15);
  --radius: 8px;
  --radius-lg: 12px;
  --max-width: 1200px;
  --nav-height: 64px;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  height: var(--nav-height);
}
.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
}
.nav-brand svg { width: 32px; height: 32px; }
.nav-menu {
  display: flex;
  list-style: none;
  gap: 4px;
}
.nav-menu a {
  display: block;
  padding: 8px 18px;
  border-radius: 20px;
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  transition: all 0.2s ease;
}
.nav-menu a:hover {
  color: var(--primary);
  background: rgba(26,115,232,0.06);
}
.nav-menu a.active {
  color: var(--primary);
  background: rgba(26,115,232,0.1);
}
.mobile-toggle { display: none; background: none; border: none; cursor: pointer; }

.hero {
  background: linear-gradient(180deg, #e8f0fe 0%, var(--bg) 100%);
  padding: 80px 24px 60px;
  text-align: center;
}
.hero-container {
  max-width: var(--max-width);
  margin: 0 auto;
}
.hero h1 {
  font-size: 3rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 16px;
  line-height: 1.2;
}
.hero .subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto 36px;
}
.hero-actions {
  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;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 2px 8px rgba(26,115,232,0.3);
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-hover);
}
.btn-secondary {
  background: var(--bg);
  color: var(--primary);
  border: 1.5px solid var(--border);
}
.btn-secondary:hover {
  border-color: var(--primary);
  background: rgba(26,115,232,0.04);
}

.section {
  padding: 64px 24px;
  max-width: var(--max-width);
  margin: 0 auto;
}
.section-title {
  font-size: 2rem;
  font-weight: 600;
  text-align: center;
  margin-bottom: 12px;
}
.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 48px;
  font-size: 1.05rem;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}
.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all 0.25s ease;
}
.card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}
.card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}
.card-icon.blue { background: #e8f0fe; color: var(--primary); }
.card-icon.green { background: #e6f4ea; color: var(--secondary); }
.card-icon.yellow { background: #fef3e8; color: #f9ab00; }
.card-icon.red { background: #fce8e8; color: var(--danger); }
.card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 10px;
}
.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.platforms-section { background: var(--bg-alt); }
.platforms-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 64px 24px;
}
.platform-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  text-align: center;
  transition: all 0.2s ease;
}
.platform-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}
.platform-card svg {
  width: 40px;
  height: 40px;
  margin-bottom: 12px;
  color: var(--text-secondary);
}
.platform-card h4 {
  font-size: 1rem;
  margin-bottom: 4px;
}
.platform-card span {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.download-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 24px;
}
.download-table th, .download-table td {
  padding: 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.download-table th {
  background: var(--bg-alt);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.download-table tr:hover td {
  background: var(--bg-alt);
}

.steps {
  display: flex;
  gap: 24px;
  counter-reset: step;
  flex-wrap: wrap;
}
.step {
  flex: 1;
  min-width: 220px;
  position: relative;
  padding-left: 56px;
}
.step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
}
.step h4 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  padding-top: 8px;
}
.step p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}
.faq-item[open] summary { background: var(--bg-alt); }
.faq-item summary {
  padding: 18px 24px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background 0.2s;
}
.faq-item summary:hover { background: var(--bg-alt); }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--text-secondary);
  font-weight: 400;
}
.faq-item[open] summary::after { content: "\2212"; }
.faq-item .faq-answer {
  padding: 0 24px 20px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.changelog { max-width: 800px; margin: 0 auto; }
.changelog-entry {
  display: flex;
  gap: 24px;
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
}
.changelog-entry .version {
  min-width: 100px;
  font-weight: 700;
  color: var(--primary);
  font-size: 1.1rem;
}
.changelog-entry .date {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}
.changelog-entry ul {
  margin-left: 18px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.cta-banner {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: var(--radius-lg);
  padding: 56px 40px;
  text-align: center;
  color: #fff;
  margin: 48px auto;
  max-width: var(--max-width);
}
.cta-banner h2 {
  font-size: 1.8rem;
  margin-bottom: 12px;
}
.cta-banner p {
  opacity: 0.9;
  margin-bottom: 28px;
  font-size: 1.05rem;
}
.cta-banner .btn-light {
  background: #fff;
  color: var(--primary);
  padding: 14px 36px;
  border-radius: var(--radius);
  font-weight: 600;
  text-decoration: none;
  display: inline-block;
  transition: all 0.2s;
}
.cta-banner .btn-light:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 32px;
  text-align: center;
}
.stat-item .stat-number {
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1;
}
.stat-item .stat-label {
  margin-top: 8px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}
.scenario-card {
  border-radius: var(--radius-lg);
  padding: 28px;
  position: relative;
  overflow: hidden;
}
.scenario-card.work { background: linear-gradient(135deg, #e8f0fe, #d2e3fc); }
.scenario-card.study { background: linear-gradient(135deg, #e6f4ea, #ceead6); }
.scenario-card.entertainment { background: linear-gradient(135deg, #fef3e8, #fde293); }
.scenario-card.development { background: linear-gradient(135deg, #fce8e8, #fad2cf); }
.scenario-card h4 { font-size: 1.1rem; margin-bottom: 8px; }
.scenario-card p { font-size: 0.9rem; color: var(--text-secondary); }

.site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 40px 24px;
  margin-top: 80px;
}
.footer-container {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-security {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--secondary);
}
.footer-copyright {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 16px;
    gap: 4px;
  }
  .nav-menu.open { display: flex; }
  .mobile-toggle { display: block; }
  .hero h1 { font-size: 2rem; }
  .hero { padding: 48px 20px 40px; }
  .section { padding: 48px 20px; }
  .section-title { font-size: 1.6rem; }
  .footer-container { flex-direction: column; text-align: center; }
  .btn { padding: 12px 24px; font-size: 0.95rem; }
  .cta-banner { padding: 40px 24px; margin: 32px 20px; }
  .steps { flex-direction: column; }
  .changelog-entry { flex-direction: column; gap: 8px; }
}

.bg-alt { background: var(--bg-alt); }
.full-width { max-width: 100%; padding-left: 0; padding-right: 0; }
.content-wrap { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }