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

:root {
  --primary: #4d6bfe;
  --primary-dark: #3a56d4;
  --bg-light: #e6effd;
  --text: #1e293b;
  --text-muted: #475569;
  --white: #ffffff;
  --border: #e2e8f0;
  --radius: 11px;
  --shadow: 0 4px 24px rgba(77, 107, 254, 0.12);
}

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
}

a { color: var(--primary); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--primary-dark); }

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

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 8px rgba(0,0,0,0.04);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary), #7c9aff);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: 14px;
}

.nav-menu { display: flex; list-style: none; gap: 28px; }
.nav-menu a { color: var(--text-muted); font-size: 0.95rem; font-weight: 500; }
.nav-menu a:hover, .nav-menu a.active { color: var(--primary); }
.menu-toggle { display: none; background: none; border: none; cursor: pointer; font-size: 1.5rem; color: var(--text); }

.hero {
  background: linear-gradient(160deg, var(--bg-light) 0%, #f0f5ff 50%, #e8eeff 100%);
  min-height: 520px;
  display: flex;
  align-items: center;
  text-align: center;
  padding: 80px 24px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(77,107,254,0.08) 0%, transparent 70%);
}

.hero-content { position: relative; z-index: 1; width: 100%; max-width: 800px; margin: 0 auto; }

.hero-badge {
  display: inline-block;
  background: rgba(77,107,254,0.1);
  color: var(--primary);
  padding: 8px 20px;
  border-radius: 20px;
  font-size: 0.9rem;
  margin-bottom: 24px;
}

.hero-title { font-size: 2.8rem; font-weight: 800; color: var(--text); margin-bottom: 16px; letter-spacing: -0.5px; }
.hero-subtitle { font-size: 1.15rem; color: var(--text-muted); margin-bottom: 40px; line-height: 1.8; }

.hero-logo-text {
  font-size: 3rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary), #6b8cff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 36px;
}

.btn-group { display: flex; gap: 20px; 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;
  cursor: pointer;
  border: none;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--primary); color: var(--white); box-shadow: var(--shadow); }
.btn-primary:hover { background: var(--primary-dark); color: var(--white); }
.btn-outline { background: var(--white); color: var(--primary); border: 2px solid var(--primary); }
.btn-outline:hover { background: var(--bg-light); color: var(--primary); }

.section { padding: 80px 24px; }
.section-title { text-align: center; font-size: 1.8rem; color: var(--text-muted); margin-bottom: 20px; }
.section-desc { text-align: center; color: var(--text-muted); max-width: 680px; margin: 0 auto 48px; font-size: 1.05rem; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
  max-width: 1000px;
  margin: 0 auto;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  transition: box-shadow 0.2s;
}

.feature-card:hover { box-shadow: var(--shadow); }

.feature-icon {
  width: 56px;
  height: 56px;
  background: var(--bg-light);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 1.5rem;
}

.feature-card h3 { font-size: 1.1rem; margin-bottom: 10px; color: var(--text); }
.feature-card p { color: var(--text-muted); font-size: 0.95rem; }

.stats-box {
  max-width: 780px;
  margin: 0 auto;
  background: linear-gradient(135deg, #f8faff, var(--bg-light));
  border-radius: var(--radius);
  padding: 48px;
  text-align: center;
  border: 1px solid var(--border);
}

.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 32px; }
.stat-item h4 { font-size: 2rem; color: var(--primary); font-weight: 800; }
.stat-item p { color: var(--text-muted); font-size: 0.9rem; margin-top: 4px; }

.articles-section { background: #f8fafc; }
.article-list { max-width: 900px; margin: 0 auto; }

.article-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin-bottom: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: box-shadow 0.2s;
}

.article-item:hover { box-shadow: var(--shadow); }
.article-item h3 { font-size: 1.05rem; margin-bottom: 6px; }
.article-item .meta { font-size: 0.85rem; color: #94a3b8; }
.article-item .tag {
  display: inline-block;
  background: var(--bg-light);
  color: var(--primary);
  padding: 2px 10px;
  border-radius: 4px;
  font-size: 0.8rem;
  margin-right: 8px;
}

.daily-update-badge {
  background: #dcfce7;
  color: #16a34a;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  white-space: nowrap;
}

.download-hero {
  background: linear-gradient(160deg, var(--bg-light), #f0f5ff);
  padding: 100px 24px;
  text-align: center;
}

.download-card {
  max-width: 560px;
  margin: 48px auto 0;
  background: var(--white);
  border-radius: var(--radius);
  padding: 48px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.download-card h2 { font-size: 1.6rem; margin-bottom: 12px; }
.download-card p { color: var(--text-muted); margin-bottom: 32px; }

.platform-list { display: flex; flex-direction: column; gap: 12px; margin-bottom: 32px; }

.platform-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: #f8fafc;
  border-radius: 8px;
  font-size: 0.95rem;
}

.platform-item span:first-child { font-size: 1.3rem; }

.article-header { background: var(--bg-light); padding: 60px 24px 40px; text-align: center; }
.article-header h1 { font-size: 2rem; margin-bottom: 12px; }
.article-header .meta { color: var(--text-muted); font-size: 0.9rem; }

.article-body { max-width: 760px; margin: 0 auto; padding: 48px 24px 80px; }
.article-body h2 { font-size: 1.4rem; margin: 36px 0 16px; color: var(--text); }
.article-body h3 { font-size: 1.15rem; margin: 28px 0 12px; }
.article-body p { margin-bottom: 18px; color: var(--text-muted); }
.article-body ul, .article-body ol { margin: 0 0 18px 24px; color: var(--text-muted); }
.article-body li { margin-bottom: 8px; }
.article-body blockquote {
  border-left: 4px solid var(--primary);
  padding: 16px 20px;
  background: var(--bg-light);
  border-radius: 0 8px 8px 0;
  margin: 24px 0;
  color: var(--text-muted);
}

.site-footer { background: #0f172a; color: #94a3b8; padding: 60px 24px 24px; }

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  max-width: 1200px;
  margin: 0 auto 40px;
}

.footer-col h3 { color: var(--white); font-size: 1rem; margin-bottom: 16px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a { color: #94a3b8; font-size: 0.9rem; }
.footer-col a:hover { color: var(--white); }

.footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid #1e293b;
  font-size: 0.85rem;
  max-width: 1200px;
  margin: 0 auto;
}

.sitemap-list { max-width: 700px; margin: 0 auto; list-style: none; }
.sitemap-list li {
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.sitemap-list a { font-weight: 500; }

@media (max-width: 768px) {
  .nav-menu { display: none; }
  .nav-menu.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--white);
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
    gap: 16px;
  }
  .menu-toggle { display: block; }
  .hero-title { font-size: 2rem; }
  .hero-logo-text { font-size: 2.2rem; }
  .stats-grid { grid-template-columns: 1fr; }
  .article-item { flex-direction: column; align-items: flex-start; }
}