:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.08);
  --max: 1100px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; transition: color .15s; }
a:hover { color: var(--primary-dark); }

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

.container { max-width: var(--max); margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.logo {
  font-size: 20px; font-weight: 700; color: var(--text);
  display: flex; align-items: center; gap: 8px;
}
.logo span { color: var(--primary); }
.nav { display: flex; align-items: center; gap: 28px; }
.nav a { color: var(--text-muted); font-weight: 500; font-size: 15px; }
.nav a:hover, .nav a.active { color: var(--primary); }

.lang-switch {
  display: flex; gap: 4px; align-items: center;
  border: 1px solid var(--border); border-radius: 8px; padding: 2px;
}
.lang-switch a {
  font-size: 13px; padding: 4px 10px; border-radius: 6px;
  color: var(--text-muted); font-weight: 600;
}
.lang-switch a.active { background: var(--primary); color: #fff; }

.menu-toggle { display: none; background: none; border: none; cursor: pointer; font-size: 24px; }

/* Hero */
.hero {
  padding: 80px 0 60px;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-soft) 0%, var(--bg) 100%);
}
.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 800; line-height: 1.15; letter-spacing: -0.02em;
  margin-bottom: 20px;
}
.hero h1 .accent { color: var(--primary); }
.hero p {
  font-size: 19px; color: var(--text-muted);
  max-width: 640px; margin: 0 auto 32px;
}
.btn {
  display: inline-block; background: var(--primary); color: #fff;
  padding: 14px 32px; border-radius: var(--radius); font-weight: 600;
  font-size: 16px; box-shadow: var(--shadow); transition: all .2s;
}
.btn:hover { background: var(--primary-dark); color: #fff; transform: translateY(-1px); box-shadow: var(--shadow-lg); }
.btn-outline {
  background: transparent; color: var(--primary);
  border: 2px solid var(--primary); margin-left: 12px;
}
.btn-outline:hover { background: var(--primary); color: #fff; }

/* Sections */
.section { padding: 64px 0; }
.section-title { font-size: 32px; font-weight: 700; text-align: center; margin-bottom: 12px; letter-spacing: -0.01em; }
.section-sub { text-align: center; color: var(--text-muted); margin-bottom: 48px; font-size: 17px; }

/* Features grid */
.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.feature {
  background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 28px;
}
.feature .icon {
  width: 48px; height: 48px; border-radius: 12px;
  background: var(--primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 24px; margin-bottom: 16px;
}
.feature h3 { font-size: 19px; margin-bottom: 8px; }
.feature p { color: var(--text-muted); font-size: 15px; }

/* Blog cards */
.blog-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 28px; }
.blog-card {
  border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; background: var(--bg); transition: all .2s;
  display: flex; flex-direction: column;
}
.blog-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px); }
.blog-card .card-body { padding: 24px; flex: 1; display: flex; flex-direction: column; }
.blog-card .card-meta { font-size: 13px; color: var(--text-muted); margin-bottom: 10px; }
.blog-card h3 { font-size: 20px; margin-bottom: 10px; line-height: 1.3; }
.blog-card h3 a { color: var(--text); }
.blog-card h3 a:hover { color: var(--primary); }
.blog-card p { color: var(--text-muted); font-size: 15px; flex: 1; }
.blog-card .read-more { margin-top: 16px; font-weight: 600; font-size: 14px; }

/* Article */
.article { max-width: 760px; margin: 0 auto; padding: 48px 0; }
.article .breadcrumb { font-size: 14px; color: var(--text-muted); margin-bottom: 24px; }
.article h1 { font-size: clamp(28px, 4vw, 40px); font-weight: 800; line-height: 1.2; margin-bottom: 16px; letter-spacing: -0.02em; }
.article .article-meta { color: var(--text-muted); font-size: 15px; margin-bottom: 32px; padding-bottom: 24px; border-bottom: 1px solid var(--border); }
.article-content h2 { font-size: 26px; font-weight: 700; margin: 36px 0 16px; letter-spacing: -0.01em; }
.article-content h3 { font-size: 21px; font-weight: 600; margin: 28px 0 12px; }
.article-content p { margin-bottom: 18px; }
.article-content ul, .article-content ol { margin: 0 0 18px 24px; }
.article-content li { margin-bottom: 8px; }
.article-content table { width: 100%; border-collapse: collapse; margin: 20px 0; font-size: 15px; }
.article-content th, .article-content td { padding: 10px; border: 1px solid var(--border); text-align: left; }
.article-content th { background: var(--bg-soft); font-weight: 600; }
.article-content em { color: var(--text-muted); }

.ad-slot {
  margin: 32px 0; padding: 20px; text-align: center;
  background: var(--bg-soft); border: 1px dashed var(--border);
  border-radius: var(--radius); color: var(--text-muted); font-size: 13px;
  min-height: 100px; display: flex; align-items: center; justify-content: center;
}

/* CTA box */
.cta-box {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff; border-radius: var(--radius); padding: 48px; text-align: center;
  margin: 48px 0;
}
.cta-box h2 { color: #fff; font-size: 28px; margin-bottom: 12px; }
.cta-box p { color: rgba(255,255,255,0.9); margin-bottom: 24px; }
.cta-box .btn { background: #fff; color: var(--primary); }
.cta-box .btn:hover { background: var(--bg-soft); }

/* Footer */
.site-footer { background: var(--bg-soft); border-top: 1px solid var(--border); padding: 48px 0 32px; margin-top: 64px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 32px; }
.footer-col h4 { font-size: 15px; font-weight: 700; margin-bottom: 16px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { color: var(--text-muted); font-size: 14px; }
.footer-col a:hover { color: var(--primary); }
.footer-about p { color: var(--text-muted); font-size: 14px; margin-top: 12px; max-width: 320px; }
.footer-bottom { text-align: center; padding-top: 24px; border-top: 1px solid var(--border); color: var(--text-muted); font-size: 14px; }

/* Static pages */
.page { max-width: 760px; margin: 0 auto; padding: 48px 0; }
.page h1 { font-size: 36px; font-weight: 800; margin-bottom: 24px; }
.page h2 { font-size: 24px; font-weight: 700; margin: 32px 0 12px; }
.page p { margin-bottom: 16px; }
.page ul { margin: 0 0 16px 24px; }

/* Contact form */
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-weight: 600; margin-bottom: 6px; font-size: 15px; }
.form-group input, .form-group textarea {
  width: 100%; padding: 12px 16px; border: 1px solid var(--border);
  border-radius: 8px; font-size: 15px; font-family: inherit;
}
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: var(--primary); }
.alert { padding: 14px 18px; border-radius: 8px; margin-bottom: 20px; font-size: 15px; }
.alert-success { background: #dcfce7; color: #166534; border: 1px solid #bbf7d0; }

/* Mobile */
@media (max-width: 768px) {
  .nav { display: none; position: absolute; top: 64px; left: 0; right: 0; background: var(--bg); flex-direction: column; padding: 20px; gap: 16px; border-bottom: 1px solid var(--border); box-shadow: var(--shadow-lg); }
  .nav.open { display: flex; }
  .menu-toggle { display: block; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .hero { padding: 56px 0 40px; }
  .btn-outline { margin-left: 0; margin-top: 12px; }
  .cta-box { padding: 32px 24px; }
}