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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #06b6d4;
  --text: #1e293b;
  --text-muted: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --shadow: 0 4px 24px rgba(37, 99, 235, 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);
  line-height: 1.7;
  background: var(--bg);
}

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

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

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--primary);
}

.logo img { width: 36px; height: 36px; }

.nav { display: flex; gap: 28px; align-items: center; }
.nav a { color: var(--text); font-size: 0.95rem; font-weight: 500; }
.nav a:hover { color: var(--primary); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.45);
  color: #fff;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}

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

.menu-toggle { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; }

/* Hero */
.hero {
  background: linear-gradient(135deg, #eff6ff 0%, #ecfeff 50%, #f0fdf4 100%);
  padding: 80px 0 60px;
  text-align: center;
}

.hero h1 {
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

.hero-features {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  margin-bottom: 36px;
}

.hero-tag {
  background: #fff;
  padding: 8px 18px;
  border-radius: 20px;
  font-size: 0.9rem;
  color: var(--text);
  box-shadow: var(--shadow);
}

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

/* Sections */
.section { padding: 72px 0; }
.section-alt { background: var(--bg-alt); }

.section-title {
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.section-desc {
  text-align: center;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 48px;
}

/* Feature grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 28px;
}

.feature-card {
  background: #fff;
  padding: 32px 28px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform 0.2s;
}

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

.feature-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 18px;
}

.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; }
.feature-card p { color: var(--text-muted); font-size: 0.95rem; }

/* Stats bar */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
  text-align: center;
  padding: 48px 0;
}

.stat-num { font-size: 2.2rem; font-weight: 800; color: var(--primary); }
.stat-label { color: var(--text-muted); font-size: 0.9rem; margin-top: 4px; }

/* Reviews */
.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.review-card {
  background: #fff;
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.review-author { font-weight: 600; margin-bottom: 4px; }
.review-role { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 12px; }
.review-stars { color: #f59e0b; margin-bottom: 12px; letter-spacing: 2px; }
.review-text { color: var(--text-muted); font-size: 0.95rem; }

/* Pricing */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 28px;
  max-width: 900px;
  margin: 0 auto;
}

.pricing-card {
  background: #fff;
  padding: 36px 28px;
  border-radius: var(--radius);
  border: 2px solid var(--border);
  text-align: center;
  transition: border-color 0.2s;
}

.pricing-card.featured {
  border-color: var(--primary);
  box-shadow: 0 8px 32px rgba(37, 99, 235, 0.15);
  position: relative;
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary);
  color: #fff;
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 0.8rem;
}

.pricing-card h3 { font-size: 1.2rem; margin-bottom: 16px; }
.pricing-price { font-size: 2.4rem; font-weight: 800; color: var(--primary); margin-bottom: 20px; }
.pricing-note { font-size: 0.85rem; color: var(--text-muted); margin-top: 24px; }

/* News */
.news-list { display: flex; flex-direction: column; gap: 20px; max-width: 800px; margin: 0 auto; }

.news-item {
  display: block;
  background: #fff;
  padding: 24px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: box-shadow 0.2s;
}

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

.news-date { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 8px; }
.news-item h3 { font-size: 1.1rem; margin-bottom: 8px; color: var(--text); }
.news-item p { color: var(--text-muted); font-size: 0.95rem; }
.news-more { font-size: 0.9rem; margin-top: 10px; display: inline-block; }

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

.faq-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 20px 24px;
  background: none;
  border: none;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text);
}

.faq-question::after { content: "+"; font-size: 1.3rem; color: var(--primary); }
.faq-item.active .faq-question::after { content: "−"; }

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer { max-height: 500px; }

.faq-answer-inner {
  padding: 0 24px 20px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* CTA */
.cta-section {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  padding: 64px 0;
  text-align: center;
  color: #fff;
}

.cta-section h2 { font-size: 1.8rem; margin-bottom: 24px; }
.cta-section .btn-primary { background: #fff; color: var(--primary); box-shadow: 0 4px 14px rgba(0,0,0,0.15); }
.cta-section .btn-primary:hover { color: var(--primary-dark); }

/* Footer */
.site-footer {
  background: #0f172a;
  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: #fff; margin-bottom: 16px; font-size: 1rem; }
.footer-grid ul { list-style: none; }
.footer-grid li { margin-bottom: 8px; }
.footer-grid a { color: #94a3b8; font-size: 0.9rem; }
.footer-grid a:hover { color: #fff; }

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

/* Download page */
.download-hero { padding: 60px 0 40px; text-align: center; }
.download-hero h1 { font-size: 2.2rem; margin-bottom: 12px; }

.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  margin: 40px 0;
}

.platform-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  box-shadow: var(--shadow);
}

.platform-icon { font-size: 3rem; margin-bottom: 16px; }
.platform-card h3 { margin-bottom: 8px; }
.platform-card p { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 20px; }

.download-steps {
  max-width: 700px;
  margin: 48px auto;
}

.download-steps ol { padding-left: 24px; }
.download-steps li { margin-bottom: 16px; color: var(--text-muted); }

/* Article page */
.article-header { padding: 48px 0 32px; border-bottom: 1px solid var(--border); }
.article-header h1 { font-size: 2rem; margin-bottom: 12px; line-height: 1.4; }
.article-meta { color: var(--text-muted); font-size: 0.9rem; }

.article-body {
  max-width: 760px;
  margin: 0 auto;
  padding: 40px 20px 64px;
}

.article-body h2 { font-size: 1.4rem; margin: 36px 0 16px; color: var(--text); }
.article-body h3 { font-size: 1.15rem; margin: 24px 0 12px; }
.article-body p { margin-bottom: 16px; color: var(--text-muted); }
.article-body ul, .article-body ol { margin: 0 0 16px 24px; color: var(--text-muted); }
.article-body li { margin-bottom: 8px; }

.breadcrumb {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

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

.related-articles {
  background: var(--bg-alt);
  padding: 48px 0;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.related-card {
  background: #fff;
  padding: 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.related-card h3 { font-size: 1rem; margin-bottom: 8px; }

@media (max-width: 768px) {
  .menu-toggle { display: block; }
  .nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 20px;
    border-bottom: 1px solid var(--border);
    gap: 16px;
  }
  .nav.open { display: flex; }
  .hero h1 { font-size: 1.8rem; }
  .section-title { font-size: 1.5rem; }
}