:root {
  --primary: #3b82f6; /* Electric Blue */
  --secondary: #10b981; /* Emerald Green */
  --accent: #f59e0b; /* Amber Gold */
  --bg-main: #f8fafc; /* Slate Light */
  --bg-card: #ffffff;
  --text-main: #0f172a; /* Navy Depth */
  --text-muted: #64748b;
  --nav-bg: rgba(255, 255, 255, 0.85);
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --radius: 12px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }

.wrap { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  height: 72px;
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--primary);
}
.nav-menu {
  display: flex;
  gap: 32px;
}
.nav-link {
  font-weight: 500;
  color: var(--text-muted);
  transition: 0.2s;
  padding: 8px 0;
  position: relative;
}
.nav-link:hover { color: var(--primary); }
.nav-link.active { color: var(--text-main); }
.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary);
}

.nav-toggle { display: none; cursor: pointer; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  border: none;
  font-size: 1rem;
}
.btn-primary {
  background: var(--primary);
  color: white;
}
.btn-primary:hover {
  background: #2563eb;
  transform: translateY(-2px);
  box-shadow: 0 10px 15px -3px rgba(59, 130, 246, 0.3);
}
.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-main);
}
.btn-outline:hover {
  background: #f1f5f9;
}

/* Sections */
.sec { padding: 80px 0; }
.sec-head { text-align: center; margin-bottom: 50px; }
.sec-title { font-size: 2.5rem; margin-bottom: 16px; font-weight: 800; }
.sec-desc { font-size: 1.125rem; color: var(--text-muted); max-width: 600px; margin: 0 auto; }

/* Hero */
.hero {
  padding: 120px 0 80px;
  background: radial-gradient(circle at 80% 20%, rgba(59, 130, 246, 0.05) 0%, transparent 40%),
              radial-gradient(circle at 20% 80%, rgba(16, 185, 129, 0.05) 0%, transparent 40%);
}
.hero-inner {
  display: flex;
  align-items: center;
  gap: 60px;
}
.hero-content { flex: 1; }
.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(59, 130, 246, 0.1);
  color: var(--primary);
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 24px;
}
.hero-title { font-size: 4rem; line-height: 1.1; margin-bottom: 24px; font-weight: 800; }
.hero-p { font-size: 1.25rem; color: var(--text-muted); margin-bottom: 40px; }
.hero-btns { display: flex; gap: 16px; }

.hero-visual {
  flex: 1;
  position: relative;
}
.mockup-frame {
  background: var(--bg-card);
  border-radius: 16px;
  border: 1px solid var(--border);
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.1);
  padding: 10px;
  overflow: hidden;
}
.mockup-header {
  height: 40px;
  background: #f1f5f9;
  border-radius: 8px 8px 0 0;
  display: flex;
  align-items: center;
  padding: 0 15px;
  gap: 8px;
}
.dot { width: 10px; height: 10px; border-radius: 50%; }
.dot-r { background: #ef4444; }
.dot-y { background: #f59e0b; }
.dot-g { background: #10b981; }
.mockup-body {
  height: 300px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 15px;
  padding: 20px;
}
.mockup-item {
  background: #f8fafc;
  border-radius: 10px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 10px;
}
.mockup-line { height: 8px; background: #e2e8f0; border-radius: 4px; width: 60%; }

/* Features */
.feat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}
.feat-card {
  background: var(--bg-card);
  padding: 40px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: 0.3s;
}
.feat-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow);
  border-color: var(--primary);
}
.feat-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  background: rgba(59, 130, 246, 0.08);
  color: var(--primary);
}
.feat-name { font-size: 1.25rem; font-weight: 700; margin-bottom: 12px; }
.feat-desc { color: var(--text-muted); font-size: 0.95rem; }

/* Platform Cards */
.plat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.plat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  text-align: center;
  transition: 0.3s;
}
.plat-card:hover { border-color: var(--primary); background: #fdfdfd; }
.plat-ico { width: 48px; height: 48px; margin: 0 auto 20px; color: var(--text-main); }
.plat-name { font-weight: 700; margin-bottom: 8px; }
.plat-ver { font-size: 0.875rem; color: var(--text-muted); margin-bottom: 20px; }

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 16px;
  overflow: hidden;
}
.faq-q {
  padding: 24px 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 600;
  transition: 0.2s;
}
.faq-q:hover { background: #f8fafc; }
.faq-chevron {
  width: 20px;
  height: 20px;
  transition: 0.3s;
}
.faq-item.open .faq-chevron { transform: rotate(180deg); color: var(--primary); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.faq-item.open .faq-a { max-height: 300px; }
.faq-a-inner { padding: 0 30px 24px; color: var(--text-muted); font-size: 0.95rem; }

/* Footer */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 60px 0 40px;
  font-size: 0.875rem;
}
.footer-inner { text-align: center; }
.footer-logo { color: white; font-weight: 700; font-size: 1.5rem; margin-bottom: 20px; }
.footer-security { color: #10b981; margin-bottom: 12px; font-weight: 500; }
.footer-note { max-width: 600px; margin: 0 auto; line-height: 1.8; }

/* Download Page Specifics */
.dl-hero { padding: 80px 0; text-align: center; }
.dl-main-card {
  max-width: 900px;
  margin: 0 auto 60px;
  background: var(--bg-card);
  border-radius: 24px;
  padding: 60px;
  display: flex;
  gap: 60px;
  border: 1px solid var(--border);
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.05);
}
.dl-main-info { flex: 1; text-align: left; }
.dl-win-title { font-size: 2rem; font-weight: 800; margin-bottom: 15px; }
.dl-specs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 15px;
  margin-top: 30px;
}
.dl-spec {
  font-size: 0.9rem;
}
.dl-spec-lbl { color: var(--text-muted); margin-bottom: 4px; }
.dl-spec-val { font-weight: 600; }

/* Article Layout (zh-cn.html) */
.art-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 50px;
  margin-top: 50px;
}
.art-body h2 { font-size: 1.75rem; margin: 40px 0 20px; }
.art-body p { margin-bottom: 20px; color: #334155; }
.art-body ul { margin-bottom: 20px; padding-left: 20px; }
.art-body li { margin-bottom: 10px; }

.sidebar { position: sticky; top: 100px; height: fit-content; }
.side-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}
.side-title { font-weight: 700; margin-bottom: 16px; font-size: 1.1rem; }

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

/* Mobile Responsive */
@media (max-width: 992px) {
  .hero-inner { flex-direction: column; text-align: center; }
  .hero-title { font-size: 3rem; }
  .feat-grid { grid-template-columns: 1fr 1fr; }
  .plat-grid { grid-template-columns: 1fr 1fr; }
  .art-layout { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: white;
    flex-direction: column;
    padding: 20px;
    gap: 15px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
  }
  .nav-menu.show { display: flex; }
  .nav-toggle { display: block; }
  .feat-grid { grid-template-columns: 1fr; }
  .dl-main-card { flex-direction: column; padding: 40px 20px; }
}