:root {
  --navy: #1a4a5e;
  --navy-dark: #12384a;
  --blue: #3d8db8;
  --slate: #4a5b66;
  --bg: #ffffff;
  --bg-alt: #f4f7f9;
  --border: #e2e8ec;
  --text: #1f2933;
  --muted: #5a6b76;
  --max-width: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

h1, h2, h3, h4 {
  color: var(--navy);
  line-height: 1.25;
  margin: 0 0 0.5em;
}

h1 { font-size: 2.4rem; font-weight: 700; }
h2 { font-size: 1.8rem; font-weight: 700; }
h3 { font-size: 1.25rem; font-weight: 600; }

p { margin: 0 0 1em; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ---------- Header ---------- */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.75rem;
  padding-bottom: 0.75rem;
}
.logo img { height: 40px; }
.nav ul {
  list-style: none;
  display: flex;
  gap: 1.75rem;
  margin: 0;
  padding: 0;
}
.nav a {
  color: var(--navy);
  font-weight: 500;
}
.nav a.active { color: var(--blue); }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-dark) 100%);
  color: #fff;
  padding: 5rem 0;
}
.hero h1 { color: #fff; max-width: 780px; }
.hero p.lead {
  font-size: 1.2rem;
  color: #d3e0e6;
  max-width: 720px;
  margin-bottom: 2rem;
}
.hero .btn { background: var(--blue); color: #fff; }
.hero .btn:hover { background: #4fa2cf; }

/* ---------- Page header (interior pages) ---------- */
.page-header {
  background: var(--bg-alt);
  padding: 3rem 0;
  border-bottom: 1px solid var(--border);
}
.page-header p {
  color: var(--muted);
  font-size: 1.1rem;
  max-width: 720px;
  margin: 0;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 0.85rem 1.6rem;
  border-radius: 4px;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.15s ease;
}
.btn-primary { background: var(--navy); color: #fff; }
.btn-primary:hover { background: var(--navy-dark); text-decoration: none; }

/* ---------- Sections ---------- */
section { padding: 4rem 0; }
section.alt { background: var(--bg-alt); }

.section-intro {
  max-width: 780px;
  margin-bottom: 2.5rem;
}
.section-intro p { color: var(--muted); font-size: 1.05rem; }

/* ---------- Capability cards ---------- */
.capabilities-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}
.capability-card {
  background: #fff;
  border: 1px solid var(--border);
  border-top: 3px solid var(--blue);
  border-radius: 4px;
  padding: 1.75rem;
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}
.capability-card:hover {
  box-shadow: 0 6px 18px rgba(26, 74, 94, 0.1);
  transform: translateY(-2px);
}
.capability-card h3 { color: var(--navy); }
.capability-card p { color: var(--muted); margin: 0; }

/* ---------- Detail sections (capabilities page) ---------- */
.capability-detail {
  padding: 3rem 0;
  border-bottom: 1px solid var(--border);
}
.capability-detail:last-child { border-bottom: none; }
.capability-detail h2 {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}
.capability-detail h2 .num {
  color: var(--blue);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 0.05em;
}

/* ---------- Model image ---------- */
.model-figure {
  margin: 2rem auto;
  max-width: 720px;
  text-align: center;
}
.model-figure img {
  margin: 0 auto;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1rem;
  background: #fff;
}
.model-figure figcaption {
  color: var(--muted);
  font-size: 0.9rem;
  margin-top: 0.75rem;
}

/* ---------- Contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}
.contact-info h3 { margin-top: 0; }
.contact-info p { color: var(--muted); }
.contact-info a { color: var(--navy); font-weight: 500; }

form label {
  display: block;
  font-weight: 500;
  color: var(--navy);
  margin: 0 0 0.35rem;
}
form input, form textarea {
  width: 100%;
  padding: 0.65rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  font: inherit;
  margin-bottom: 1rem;
  background: #fff;
}
form input:focus, form textarea:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(61, 141, 184, 0.15);
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--navy-dark);
  color: #b8c8d0;
  padding: 2.5rem 0;
  font-size: 0.9rem;
}
.site-footer .container {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}
.site-footer a { color: #d3e0e6; }

/* ---------- Responsive ---------- */
@media (max-width: 700px) {
  h1 { font-size: 1.9rem; }
  h2 { font-size: 1.5rem; }
  .hero { padding: 3rem 0; }
  .nav ul { gap: 1rem; }
  .contact-grid { grid-template-columns: 1fr; gap: 2rem; }
  .site-header .container { flex-direction: column; align-items: flex-start; gap: 0.75rem; }
}