*, *::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: #cbd5e1;
  --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; }

/* 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(0,0,0,0.04);
}

.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(--text);
}

.logo-icon {
  width: 32px;
  height: 32px;
  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; gap: 28px; list-style: none; }
.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; padding: 8px; }
.menu-toggle span { display: block; width: 22px; height: 2px; background: var(--text); margin: 5px 0; }

/* Hero */
.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: 60px 24px 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(77,107,254,0.08) 0%, transparent 70%);
  top: -200px;
  right: -100px;
  border-radius: 50%;
}

.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 h1 {
  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);
  max-width: 640px;
  margin: 0 auto 36px;
}

.hero-logo-text {
  font-size: 3rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary), #2d4ed8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 32px;
  letter-spacing: 2px;
}

.cta-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); box-shadow: 0 6px 28px rgba(77,107,254,0.3); }

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

.btn-outline:hover { background: var(--bg-light); color: var(--primary-dark); }

/* Features */
.section { padding: 80px 24px; }
.section-title {
  text-align: center;
  font-size: 1.8rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.section-desc {
  text-align: center;
  color: var(--text-muted);
  max-width: 700px;
  margin: 0 auto 48px;
  font-size: 1.05rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
  max-width: 1100px;
  margin: 0 auto;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: box-shadow 0.3s, transform 0.3s;
}

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

.feature-icon {
  width: 48px;
  height: 48px;
  background: var(--bg-light);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 16px;
}

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

/* Benchmark visual */
.benchmark-box {
  max-width: 780px;
  margin: 48px auto 0;
  background: linear-gradient(180deg, #f8faff, #eef2ff);
  border-radius: var(--radius);
  padding: 40px;
  border: 1px solid var(--border);
}

.benchmark-bars { display: flex; flex-direction: column; gap: 16px; }

.bar-row { display: flex; align-items: center; gap: 16px; }
.bar-label { width: 120px; font-size: 0.85rem; color: var(--text-muted); text-align: right; flex-shrink: 0; }
.bar-track { flex: 1; height: 28px; background: #e2e8f0; border-radius: 6px; overflow: hidden; }
.bar-fill { height: 100%; border-radius: 6px; display: flex; align-items: center; padding-left: 12px; font-size: 0.8rem; font-weight: 600; color: white; }
.bar-fill.ds { background: linear-gradient(90deg, var(--primary), #6b8aff); width: 92%; }
.bar-fill.gpt { background: #94a3b8; width: 88%; }
.bar-fill.claude { background: #94a3b8; width: 85%; }
.bar-fill.gemini { background: #94a3b8; width: 82%; }

/* Articles */
.articles-section { background: #f8fafc; }
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
  max-width: 1100px;
  margin: 0 auto;
}

.article-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: box-shadow 0.3s;
}

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

.article-card-body { padding: 28px; }
.article-tag {
  display: inline-block;
  background: var(--bg-light);
  color: var(--primary);
  font-size: 0.8rem;
  padding: 4px 12px;
  border-radius: 4px;
  margin-bottom: 12px;
}

.article-card h3 { font-size: 1.15rem; margin-bottom: 10px; line-height: 1.5; }
.article-card h3 a { color: var(--text); }
.article-card h3 a:hover { color: var(--primary); }
.article-card p { color: var(--text-muted); font-size: 0.92rem; margin-bottom: 16px; }
.article-meta { font-size: 0.82rem; color: #94a3b8; }

.daily-highlight {
  background: linear-gradient(135deg, var(--primary), #5b7fff);
  color: white;
  border-radius: var(--radius);
  padding: 28px 32px;
  max-width: 1100px;
  margin: 0 auto 40px;
  text-align: center;
}

.daily-highlight h3 { font-size: 1.2rem; margin-bottom: 8px; }
.daily-highlight p { opacity: 0.92; font-size: 0.95rem; }

/* Download page */
.download-hero { padding: 60px 24px; text-align: center; background: var(--bg-light); }
.download-hero h1 { font-size: 2.2rem; margin-bottom: 12px; }
.download-hero p { color: var(--text-muted); max-width: 600px; margin: 0 auto 36px; }

.download-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 28px;
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

.download-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  transition: box-shadow 0.3s;
}

.download-card:hover { box-shadow: var(--shadow); }
.download-card .platform-icon { font-size: 3rem; margin-bottom: 16px; }
.download-card h3 { margin-bottom: 8px; }
.download-card p { color: var(--text-muted); font-size: 0.92rem; margin-bottom: 20px; }

.steps-list {
  max-width: 700px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

.steps-list ol { padding-left: 24px; }
.steps-list li { margin-bottom: 16px; color: var(--text-muted); line-height: 1.8; }
.steps-list li strong { color: var(--text); }

/* Article page */
.article-header {
  background: var(--bg-light);
  padding: 48px 24px;
  text-align: center;
}

.article-header h1 { font-size: 2rem; max-width: 800px; margin: 0 auto 16px; line-height: 1.4; }
.article-header .meta { color: var(--text-muted); font-size: 0.9rem; }

.article-content {
  max-width: 760px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}

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

/* Footer */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 60px 24px 30px;
}

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

.footer-grid h4 { color: var(--white); font-size: 0.95rem; margin-bottom: 16px; }
.footer-grid ul { list-style: none; }
.footer-grid li { margin-bottom: 10px; }
.footer-grid a { color: #94a3b8; font-size: 0.9rem; }
.footer-grid 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;
}

hr.divider { border: none; border-top: 1px solid var(--border); margin: 0; }

/* Responsive */
@media (max-width: 768px) {
  .nav-menu { display: none; position: absolute; top: 64px; left: 0; right: 0; background: var(--white); flex-direction: column; padding: 16px 24px; border-bottom: 1px solid var(--border); box-shadow: 0 4px 12px rgba(0,0,0,0.06); }
  .nav-menu.open { display: flex; }
  .menu-toggle { display: block; }
  .hero h1 { font-size: 2rem; }
  .hero-logo-text { font-size: 2.2rem; }
}