:root {
  --primary: #0066ff;
  --primary-dark: #0052cc;
  --primary-light: #e6f0ff;
  --text: #0f172a;
  --text-light: #475569;
  --text-muted: #64748b;
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --border: #e2e8f0;
  --accent: #ff6b35;
  --success: #10b981;
  --radius: 12px;
  --max-width: 1200px;
  --content-width: 760px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}
.nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  font-weight: 700;
  font-size: 22px;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}
.logo:hover { text-decoration: none; color: var(--primary); }
.logo-dot { color: var(--primary); }
.nav-links {
  display: flex;
  gap: 28px;
  align-items: center;
  list-style: none;
}
.nav-links a {
  color: var(--text-light);
  font-weight: 500;
  font-size: 15px;
}
.nav-links a:hover { color: var(--primary); text-decoration: none; }
.btn-nav {
  background: var(--primary);
  color: #fff !important;
  padding: 9px 18px;
  border-radius: 8px;
  font-weight: 600;
}
.btn-nav:hover { background: var(--primary-dark); text-decoration: none; }

/* Hero */
.hero {
  padding: 80px 24px 60px;
  background: linear-gradient(180deg, var(--primary-light) 0%, #fff 100%);
  text-align: center;
}
.hero-inner { max-width: 820px; margin: 0 auto; }
.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 20px;
}
.hero p {
  font-size: 19px;
  color: var(--text-light);
  max-width: 640px;
  margin: 0 auto 28px;
}
.hero-badge {
  display: inline-block;
  background: #fff;
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 13px;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 20px;
}

/* Blog grid */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 60px 24px;
}
.section-title {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}
.section-sub {
  color: var(--text-light);
  margin-bottom: 40px;
  font-size: 17px;
}
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
}
.blog-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all .2s ease;
  display: flex;
  flex-direction: column;
}
.blog-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(0, 102, 255, 0.08);
}
.blog-card .tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 12px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 6px;
  margin-bottom: 14px;
  align-self: flex-start;
}
.blog-card h3 {
  font-size: 20px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 12px;
  color: var(--text);
}
.blog-card h3 a { color: inherit; }
.blog-card h3 a:hover { color: var(--primary); text-decoration: none; }
.blog-card p {
  color: var(--text-light);
  font-size: 15px;
  margin-bottom: 18px;
  flex-grow: 1;
}
.blog-card .read {
  color: var(--primary);
  font-weight: 600;
  font-size: 14px;
}
.blog-card .read::after { content: " →"; }

/* Blog article */
.article-header {
  padding: 60px 24px 40px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
}
.article-header-inner {
  max-width: var(--content-width);
  margin: 0 auto;
}
.breadcrumb {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 20px;
}
.breadcrumb a { color: var(--text-muted); }
.article-header h1 {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}
.article-meta {
  color: var(--text-muted);
  font-size: 14px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}
.article-body {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 50px 24px 40px;
}
.article-body p {
  font-size: 17px;
  line-height: 1.8;
  color: var(--text);
  margin-bottom: 22px;
}
.article-body h2 {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-top: 48px;
  margin-bottom: 18px;
  line-height: 1.3;
}
.article-body h3 {
  font-size: 22px;
  font-weight: 700;
  margin-top: 34px;
  margin-bottom: 14px;
  line-height: 1.3;
}
.article-body ul, .article-body ol {
  margin: 0 0 22px 22px;
  font-size: 17px;
  line-height: 1.8;
}
.article-body li { margin-bottom: 8px; }
.article-body strong { color: var(--text); font-weight: 700; }
.article-body blockquote {
  border-left: 4px solid var(--primary);
  background: var(--primary-light);
  padding: 18px 22px;
  margin: 26px 0;
  border-radius: 0 8px 8px 0;
  color: var(--text);
  font-size: 16px;
}
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 26px 0;
  font-size: 15px;
}
.article-body th, .article-body td {
  padding: 12px 14px;
  border: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
}
.article-body th {
  background: var(--bg-soft);
  font-weight: 700;
}
.article-body tbody tr:nth-child(even) { background: var(--bg-soft); }

.callout {
  background: var(--primary-light);
  border: 1px solid #c8dcff;
  border-radius: var(--radius);
  padding: 22px 24px;
  margin: 30px 0;
}
.callout h4 {
  font-size: 16px;
  color: var(--primary-dark);
  margin-bottom: 8px;
  font-weight: 700;
}
.callout p { margin-bottom: 0; font-size: 16px; }

/* FAQ */
.faq {
  margin-top: 40px;
  padding-top: 30px;
  border-top: 1px solid var(--border);
}
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 18px 0;
}
.faq-item h3 {
  font-size: 18px;
  margin-top: 0;
  margin-bottom: 10px;
  color: var(--text);
}
.faq-item p { font-size: 16px; color: var(--text-light); margin-bottom: 0; }

/* CTA */
.cta-box {
  margin: 50px 0 20px;
  background: linear-gradient(135deg, var(--primary) 0%, #0040cc 100%);
  color: #fff;
  border-radius: var(--radius);
  padding: 40px 32px;
  text-align: center;
}
.cta-box h3 {
  font-size: 26px;
  color: #fff;
  margin-bottom: 12px;
  font-weight: 700;
  margin-top: 0;
}
.cta-box p {
  color: rgba(255,255,255,0.9);
  margin-bottom: 24px;
  font-size: 17px;
}
.cta-btn {
  display: inline-block;
  background: #fff;
  color: var(--primary) !important;
  padding: 14px 32px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 16px;
  transition: all .2s;
}
.cta-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.15);
  text-decoration: none;
}

/* Related posts */
.related {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 24px 60px;
}
.related h3 {
  font-size: 22px;
  margin-bottom: 20px;
  font-weight: 700;
}
.related-list {
  display: grid;
  gap: 14px;
}
.related-link {
  display: block;
  padding: 16px 20px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  font-weight: 600;
  transition: all .2s;
}
.related-link:hover {
  border-color: var(--primary);
  background: var(--primary-light);
  text-decoration: none;
  color: var(--primary-dark);
}
.related-link .arrow { float: right; color: var(--primary); }

/* Footer */
.footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 50px 24px 30px;
  margin-top: 60px;
}
.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
}
.footer h4 {
  color: #fff;
  font-size: 16px;
  margin-bottom: 14px;
}
.footer a { color: #94a3b8; display: block; margin-bottom: 8px; font-size: 14px; }
.footer a:hover { color: #fff; text-decoration: none; }
.footer-brand p { font-size: 14px; margin-top: 10px; max-width: 380px; }
.footer-bottom {
  max-width: var(--max-width);
  margin: 40px auto 0;
  padding-top: 24px;
  border-top: 1px solid #1e293b;
  font-size: 13px;
  color: #64748b;
  text-align: center;
}

@media (max-width: 768px) {
  .nav-links { gap: 16px; }
  .nav-links li:not(:last-child) { display: none; }
  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
  .hero { padding: 60px 20px 40px; }
  .container { padding: 40px 20px; }
}