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

:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --accent: #00b4a0;
  --text: #1f2937;
  --text-light: #6b7280;
  --bg: #f8fafc;
  --white: #ffffff;
  --border: #e5e7eb;
  --shadow: 0 4px 24px rgba(0,0,0,.08);
  --radius: 12px;
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}

a { color: var(--primary); text-decoration: none; transition: color .2s; }
a:hover { color: var(--primary-dark); }

img { max-width: 100%; height: auto; }

.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 8px rgba(0,0,0,.04);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
}

.logo img { width: 32px; height: 32px; }

.nav { display: flex; gap: 28px; list-style: none; }

.nav a {
  color: var(--text);
  font-size: 15px;
  font-weight: 500;
}

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

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--primary);
  color: var(--white) !important;
  padding: 10px 22px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 14px;
  transition: background .2s, transform .15s;
}

.btn-download:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

/* Hero */
.hero {
  background: linear-gradient(135deg, #e8f4fd 0%, #f0fdf9 50%, #fff 100%);
  padding: 72px 0 80px;
  text-align: center;
}

.hero h1 {
  font-size: 2.6rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 16px;
  line-height: 1.3;
}

.hero h1 span { color: var(--primary); }

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-light);
  max-width: 640px;
  margin: 0 auto 32px;
}

.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary);
  color: var(--white);
  padding: 14px 32px;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  transition: background .2s, transform .15s;
}

.btn-primary:hover { background: var(--primary-dark); color: var(--white); transform: translateY(-2px); }

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 2px solid var(--primary);
  color: var(--primary);
  padding: 12px 28px;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  transition: all .2s;
}

.btn-outline:hover { background: var(--primary); color: var(--white); }

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  margin-top: 48px;
  flex-wrap: wrap;
}

.stat-item { text-align: center; }

.stat-num {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--primary);
}

.stat-label { font-size: 14px; color: var(--text-light); margin-top: 4px; }

/* Sections */
.section { padding: 64px 0; }

.section-title {
  text-align: center;
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-light);
  margin-bottom: 40px;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

/* Features */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: transform .2s;
}

.feature-card:hover { transform: translateY(-4px); }

.feature-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 16px;
}

.feature-card h3 { font-size: 1.1rem; margin-bottom: 8px; }

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

/* Products */
.products { background: var(--white); }

.product-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.product-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color .2s, box-shadow .2s;
}

.product-item:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
}

.product-item h3 { font-size: 1.15rem; margin-bottom: 10px; color: var(--primary); }

.product-item p { color: var(--text-light); font-size: 15px; }

/* FAQ */
.faq-list { max-width: 760px; margin: 0 auto; }

.faq-item {
  background: var(--white);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  box-shadow: 0 1px 4px rgba(0,0,0,.04);
}

.faq-q {
  padding: 18px 24px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-q::after { content: "+"; font-size: 20px; color: var(--primary); transition: transform .2s; }

.faq-item.open .faq-q::after { transform: rotate(45deg); }

.faq-a {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: max-height .3s, padding .3s;
  color: var(--text-light);
  font-size: 15px;
}

.faq-item.open .faq-a {
  max-height: 300px;
  padding: 0 24px 18px;
}

/* Download page */
.download-hero {
  background: linear-gradient(135deg, #1a73e8, #00b4a0);
  color: var(--white);
  padding: 56px 0;
  text-align: center;
}

.download-hero h1 { font-size: 2.2rem; margin-bottom: 12px; }

.download-hero p { opacity: .9; font-size: 1.05rem; }

.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-top: -40px;
  padding-bottom: 48px;
}

.download-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  box-shadow: var(--shadow);
}

.download-card .platform-icon { font-size: 40px; margin-bottom: 12px; }

.download-card h3 { margin-bottom: 8px; }

.download-card p { color: var(--text-light); font-size: 14px; margin-bottom: 16px; }

.download-card .btn-primary { width: 100%; justify-content: center; font-size: 14px; padding: 12px; }

.install-steps {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px;
  box-shadow: var(--shadow);
}

.install-steps h2 { margin-bottom: 24px; font-size: 1.4rem; }

.install-steps ol { padding-left: 20px; }

.install-steps li { margin-bottom: 12px; color: var(--text-light); }

.install-steps li strong { color: var(--text); }

/* Articles */
.article-hero {
  background: var(--white);
  padding: 48px 0 32px;
  border-bottom: 1px solid var(--border);
}

.article-hero h1 { font-size: 2rem; margin-bottom: 12px; line-height: 1.4; }

.article-meta { color: var(--text-light); font-size: 14px; }

.article-body {
  background: var(--white);
  padding: 40px 0 64px;
}

.article-content {
  max-width: 760px;
  margin: 0 auto;
}

.article-content h2 { font-size: 1.35rem; margin: 32px 0 12px; color: var(--text); }

.article-content h3 { font-size: 1.1rem; margin: 24px 0 8px; }

.article-content p { margin-bottom: 16px; color: var(--text-light); }

.article-content ul, .article-content ol { margin: 0 0 16px 24px; color: var(--text-light); }

.article-content li { margin-bottom: 8px; }

.article-list-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform .2s;
}

.article-card:hover { transform: translateY(-3px); }

.article-card-body { padding: 24px; }

.article-card h3 { font-size: 1.1rem; margin-bottom: 8px; }

.article-card p { color: var(--text-light); font-size: 14px; margin-bottom: 12px; }

.article-card .read-more { font-size: 14px; font-weight: 600; }

/* Footer */
.site-footer {
  background: #1e293b;
  color: #94a3b8;
  padding: 48px 0 24px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  margin-bottom: 32px;
}

.footer-grid h4 { color: var(--white); margin-bottom: 14px; font-size: 15px; }

.footer-grid ul { list-style: none; }

.footer-grid li { margin-bottom: 8px; }

.footer-grid a { color: #94a3b8; font-size: 14px; }

.footer-grid a:hover { color: var(--white); }

.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 20px;
  text-align: center;
  font-size: 13px;
}

/* Breadcrumb */
.breadcrumb {
  padding: 16px 0;
  font-size: 14px;
  color: var(--text-light);
}

.breadcrumb a { color: var(--text-light); }
.breadcrumb a:hover { color: var(--primary); }

/* Responsive */
@media (max-width: 768px) {
  .nav { display: none; }
  .hero h1 { font-size: 1.8rem; }
  .hero-stats { gap: 24px; }
  .header-inner .btn-download { display: none; }
}