:root {
  --primary: #1a4d8f;
  --primary-dark: #123a6b;
  --accent: #f5a623;
  --accent-dark: #d98e0a;
  --text: #2b2b2b;
  --text-light: #5a6472;
  --bg: #ffffff;
  --bg-alt: #f4f7fb;
  --border: #e1e7ef;
  --radius: 8px;
  --shadow: 0 2px 12px rgba(26,77,143,0.08);
  --maxw: 1180px;
  --font: "Segoe UI", "Roboto", "Helvetica Neue", Arial, "Noto Sans", sans-serif;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--accent-dark); }
img { max-width: 100%; height: auto; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  padding: 14px 0;
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark {
  width: 42px; height: 42px; border-radius: 8px;
  background: var(--accent); color: #fff; font-weight: 700;
  display: flex; align-items: center; justify-content: center; font-size: 20px;
}
.logo-text { font-size: 20px; font-weight: 700; letter-spacing: .3px; }
.logo-text small { display: block; font-size: 12px; font-weight: 400; opacity: .8; }
.header-contact { text-align: right; font-size: 14px; }
.header-contact a { color: #fff; }
.header-contact .phone { font-size: 18px; font-weight: 700; color: var(--accent); }

/* Nav */
.main-nav { background: var(--primary); border-top: 1px solid rgba(255,255,255,.12); }
.main-nav .container { display: flex; flex-wrap: wrap; }
.main-nav a {
  color: #eaf1fb; padding: 12px 18px; font-size: 15px; font-weight: 500;
  border-right: 1px solid rgba(255,255,255,.08); transition: background .2s;
}
.main-nav a:hover, .main-nav a.active { background: var(--accent); color: #fff; }

/* Network bar */
.network-bar { background: var(--bg-alt); border-bottom: 1px solid var(--border); padding: 8px 0; font-size: 13px; }
.network-bar .container { display: flex; flex-wrap: wrap; gap: 6px 14px; align-items: center; }
.network-bar .nb-label { font-weight: 600; color: var(--text-light); }
.network-bar a { color: var(--text-light); padding: 2px 6px; border-radius: 4px; }
.network-bar a:hover { background: var(--primary); color: #fff; }
.network-bar a.current { background: var(--primary); color: #fff; font-weight: 600; }

/* Hero */
.hero { background: var(--bg-alt); padding: 48px 0; border-bottom: 1px solid var(--border); }
.hero h1 { font-size: 34px; color: var(--primary-dark); margin-bottom: 14px; line-height: 1.25; }
.hero p { font-size: 17px; color: var(--text-light); max-width: 760px; }
.hero .breadcrumb { font-size: 13px; color: var(--text-light); margin-bottom: 16px; }
.hero .breadcrumb a { color: var(--primary); }

/* Sections */
section { padding: 44px 0; }
section.alt { background: var(--bg-alt); }
.section-title { font-size: 26px; color: var(--primary-dark); margin-bottom: 8px; }
.section-sub { color: var(--text-light); margin-bottom: 28px; font-size: 15px; }

/* Project cards */
.project-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); gap: 22px; }
.project-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow); overflow: hidden; display: flex; flex-direction: column;
  transition: transform .2s, box-shadow .2s;
}
.project-card:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(26,77,143,.14); }
.project-thumb {
  height: 170px; background: linear-gradient(135deg, #dbe6f5, #c3d4ec);
  display: flex; align-items: center; justify-content: center; color: var(--primary-dark);
  font-size: 14px; border-bottom: 1px solid var(--border);
}
.project-body { padding: 18px 20px; flex: 1; display: flex; flex-direction: column; }
.project-tag {
  display: inline-block; font-size: 12px; font-weight: 600; padding: 3px 10px; border-radius: 20px;
  background: #eaf1fb; color: var(--primary); margin-bottom: 10px; align-self: flex-start;
}
.project-card h3 { font-size: 18px; color: var(--primary-dark); margin-bottom: 8px; }
.project-card p { font-size: 14px; color: var(--text-light); flex: 1; }
.project-meta { display: flex; gap: 14px; margin: 12px 0; font-size: 13px; color: var(--text-light); flex-wrap: wrap; }
.project-meta span { display: flex; align-items: center; gap: 4px; }
.project-card .btn { margin-top: auto; }

/* Buttons */
.btn {
  display: inline-block; padding: 11px 24px; border-radius: var(--radius); font-weight: 600;
  font-size: 15px; transition: background .2s, transform .1s; cursor: pointer; border: none;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); color: #fff; }
.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover { background: var(--accent-dark); color: #fff; }
.btn-outline { background: transparent; border: 1px solid var(--primary); color: var(--primary); }
.btn-outline:hover { background: var(--primary); color: #fff; }

/* Tables */
.table-wrap { overflow-x: auto; margin: 20px 0; }
table { width: 100%; border-collapse: collapse; font-size: 14px; background: #fff; }
th, td { padding: 11px 14px; text-align: left; border-bottom: 1px solid var(--border); }
thead th { background: var(--primary); color: #fff; font-weight: 600; }
tbody tr:nth-child(even) { background: var(--bg-alt); }
tbody tr:hover { background: #eaf1fb; }

/* TOC */
.toc {
  background: var(--bg-alt); border: 1px solid var(--border); border-left: 4px solid var(--accent);
  border-radius: var(--radius); padding: 18px 22px; margin: 24px 0;
}
.toc h4 { font-size: 15px; color: var(--primary-dark); margin-bottom: 10px; text-transform: uppercase; letter-spacing: .5px; }
.toc ol { margin-left: 20px; }
.toc li { margin: 5px 0; font-size: 14px; }

/* Key takeaways */
.key-takeaways {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 26px; margin: 24px 0; box-shadow: var(--shadow);
}
.key-takeaways h3 { font-size: 17px; color: var(--primary-dark); margin-bottom: 12px; }
.key-takeaways ul { margin-left: 20px; }
.key-takeaways li { margin: 7px 0; font-size: 15px; }

/* FAQ */
.faq-item { border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 12px; overflow: hidden; }
.faq-q { background: var(--bg-alt); padding: 14px 18px; font-weight: 600; color: var(--primary-dark); cursor: pointer; font-size: 15px; }
.faq-a { padding: 14px 18px; font-size: 14px; color: var(--text-light); }
.faq-a p { margin-bottom: 8px; }

/* CTA */
.cta {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff; border-radius: var(--radius); padding: 36px; text-align: center; margin: 36px 0;
}
.cta h2 { font-size: 24px; margin-bottom: 12px; }
.cta p { opacity: .9; margin-bottom: 20px; }

/* Article body */
.article h2 { font-size: 23px; color: var(--primary-dark); margin: 32px 0 14px; padding-bottom: 8px; border-bottom: 2px solid var(--border); }
.article h3 { font-size: 18px; color: var(--primary); margin: 22px 0 10px; }
.article p { margin-bottom: 14px; }
.article ul, .article ol { margin: 0 0 14px 22px; }
.article li { margin: 6px 0; }
.article img.placeholder {
  width: 100%; height: 240px; object-fit: cover; border-radius: var(--radius);
  background: linear-gradient(135deg, #dbe6f5, #c3d4ec); display: flex; align-items: center;
  justify-content: center; color: var(--primary-dark); font-size: 14px; margin: 18px 0; border: 1px solid var(--border);
}

/* Category grid */
.cat-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 20px; }
.cat-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; box-shadow: var(--shadow); transition: transform .2s;
}
.cat-card:hover { transform: translateY(-3px); }
.cat-card .cat-icon { font-size: 30px; margin-bottom: 10px; }
.cat-card h3 { font-size: 18px; color: var(--primary-dark); margin-bottom: 8px; }
.cat-card p { font-size: 14px; color: var(--text-light); margin-bottom: 14px; }

/* Footer */
.site-footer { background: var(--primary-dark); color: #cdd9ec; padding: 40px 0 20px; margin-top: 40px; }
.site-footer h4 { color: #fff; font-size: 16px; margin-bottom: 14px; }
.site-footer a { color: #cdd9ec; }
.site-footer a:hover { color: var(--accent); }
.footer-cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 28px; }
.footer-cols ul { list-style: none; }
.footer-cols li { margin: 7px 0; font-size: 14px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.12); margin-top: 28px; padding-top: 18px; font-size: 13px; text-align: center; color: #9fb2cf; }

/* Responsive */
@media (max-width: 768px) {
  .hero h1 { font-size: 26px; }
  .main-nav a { padding: 10px 12px; font-size: 14px; }
  .project-grid, .cat-grid { grid-template-columns: 1fr; }
  .header-contact { text-align: left; }
}