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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #7c3aed;
  --bg: #0f172a;
  --bg-card: #1e293b;
  --bg-light: #f8fafc;
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --text-dark: #1e293b;
  --border: #334155;
  --gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
  --radius: 12px;
  --shadow: 0 4px 24px rgba(0,0,0,.25);
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
  color: var(--text-dark);
  background: var(--bg-light);
}

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

.container { max-width: 1140px; margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header {
  background: var(--bg);
  padding: 14px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 1.35rem;
  font-weight: 700;
}

.logo img { width: 36px; height: 36px; border-radius: 8px; }

.nav-links { display: flex; gap: 28px; list-style: none; }
.nav-links a { color: var(--text-muted); font-size: .95rem; }
.nav-links a:hover, .nav-links a.active { color: #fff; }

.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 8px;
  font-weight: 600;
  font-size: .95rem;
  cursor: pointer;
  border: none;
  transition: transform .2s, box-shadow .2s;
}

.btn-primary {
  background: var(--gradient);
  color: #fff;
  box-shadow: 0 4px 14px rgba(37,99,235,.4);
}

.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(37,99,235,.5); color: #fff; }

.btn-outline {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255,255,255,.3);
}

.btn-outline:hover { border-color: #fff; color: #fff; }

.btn-lg { padding: 16px 36px; font-size: 1.05rem; }

/* Hero */
.hero {
  background: var(--bg);
  color: #fff;
  padding: 80px 0 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(124,58,237,.3) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-badge {
  display: inline-block;
  background: rgba(37,99,235,.2);
  border: 1px solid rgba(37,99,235,.4);
  color: #93c5fd;
  padding: 6px 16px;
  border-radius: 20px;
  font-size: .85rem;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: 2.8rem;
  line-height: 1.25;
  margin-bottom: 20px;
  max-width: 680px;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 600px;
  margin-bottom: 16px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
  font-size: .88rem;
  color: #64748b;
}

.hero-tags span::before { content: "✓ "; color: #22c55e; }

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

/* Sections */
section { padding: 72px 0; }

.section-title {
  text-align: center;
  margin-bottom: 48px;
}

.section-title h2 {
  font-size: 2rem;
  margin-bottom: 12px;
  color: var(--text-dark);
}

.section-title p { color: #64748b; font-size: 1.05rem; }

.section-dark {
  background: var(--bg);
  color: var(--text);
}

.section-dark .section-title h2 { color: #fff; }
.section-dark .section-title p { color: var(--text-muted); }

/* Cards Grid */
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }

.card {
  background: #fff;
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: 0 2px 12px rgba(0,0,0,.06);
  transition: transform .2s, box-shadow .2s;
  border: 1px solid #e2e8f0;
}

.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }

.card-icon {
  width: 48px;
  height: 48px;
  background: var(--gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 16px;
}

.card h3 { font-size: 1.15rem; margin-bottom: 8px; }
.card p { color: #64748b; font-size: .92rem; }

.card-dark {
  background: var(--bg-card);
  border-color: var(--border);
}

.card-dark h3 { color: #fff; }
.card-dark p { color: var(--text-muted); }

/* Stats */
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  text-align: center;
  margin-top: 48px;
}

.stat-num {
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label { color: var(--text-muted); margin-top: 4px; }

/* Download cards */
.download-card {
  text-align: center;
  padding: 36px 24px;
}

.download-card .card-icon { margin: 0 auto 16px; }
.download-card .btn { margin-top: 16px; width: 100%; }

/* CTA */
.cta-section {
  background: var(--gradient);
  color: #fff;
  text-align: center;
  padding: 64px 20px;
  border-radius: var(--radius);
  margin: 0 20px;
}

.cta-section h2 { font-size: 1.8rem; margin-bottom: 12px; }
.cta-section p { opacity: .9; margin-bottom: 24px; }
.cta-section .btn { background: #fff; color: var(--primary); }
.cta-section .btn:hover { color: var(--primary-dark); }

/* Blog / Articles */
.article-list { display: flex; flex-direction: column; gap: 20px; }

.article-item {
  display: flex;
  gap: 20px;
  background: #fff;
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid #e2e8f0;
  transition: box-shadow .2s;
}

.article-item:hover { box-shadow: var(--shadow); }

.article-item .date {
  flex-shrink: 0;
  width: 60px;
  text-align: center;
  background: var(--gradient);
  color: #fff;
  border-radius: 8px;
  padding: 10px 8px;
  font-size: .82rem;
  line-height: 1.3;
}

.article-item .date strong { display: block; font-size: 1.4rem; }

.article-item h3 { font-size: 1.1rem; margin-bottom: 6px; }
.article-item p { color: #64748b; font-size: .9rem; }

/* Daily update feed */
.daily-feed { margin-top: 32px; }
.daily-feed-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 16px;
}

.daily-feed-item .feed-date { color: #93c5fd; font-size: .82rem; margin-bottom: 6px; }
.daily-feed-item h4 { color: #fff; font-size: 1rem; margin-bottom: 6px; }
.daily-feed-item p { color: var(--text-muted); font-size: .88rem; }

/* Article page */
.article-page { padding: 48px 0 72px; }
.article-page .breadcrumb { font-size: .88rem; color: #64748b; margin-bottom: 24px; }
.article-page h1 { font-size: 2rem; margin-bottom: 12px; line-height: 1.35; }
.article-meta { color: #94a3b8; font-size: .88rem; margin-bottom: 32px; padding-bottom: 20px; border-bottom: 1px solid #e2e8f0; }
.article-body h2 { font-size: 1.4rem; margin: 32px 0 12px; color: var(--text-dark); }
.article-body h3 { font-size: 1.15rem; margin: 24px 0 8px; }
.article-body p { margin-bottom: 16px; color: #475569; }
.article-body ul, .article-body ol { margin: 0 0 16px 24px; color: #475569; }
.article-body li { margin-bottom: 6px; }

/* Footer */
.site-footer {
  background: var(--bg);
  color: var(--text-muted);
  padding: 48px 0 24px;
  font-size: .88rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 32px;
}

.footer-grid h4 { color: #fff; margin-bottom: 14px; font-size: .95rem; }
.footer-grid ul { list-style: none; }
.footer-grid li { margin-bottom: 8px; }
.footer-grid a { color: var(--text-muted); }
.footer-grid a:hover { color: #fff; }

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 20px;
  text-align: center;
}

/* Download page */
.platform-grid { margin-top: 32px; }

/* Responsive */
@media (max-width: 900px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 2rem; }
  .nav-links { gap: 16px; font-size: .85rem; }
  .stats-row { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .grid-4 { grid-template-columns: 1fr; }
  .header-inner { flex-wrap: wrap; gap: 12px; }
  .nav-links { width: 100%; justify-content: center; }
}