:root {
  --color-bg: #f5f7fa;
  --color-surface: #fff;
  --color-surface-muted: #e8edf3;
  --color-text: #1f2933;
  --color-border: #d9e2ec;
  --color-primary: #183b63;
  --color-primary-strong: #102a43;
  --color-accent: #0f766e;
  --shadow-soft: 0 18px 40px rgba(15, 23, 42, 0.08);
  --container-width: 72rem;
  --radius: 1rem;
}

*, *::before, *::after { box-sizing: border-box; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
  color: var(--color-text);
  background: linear-gradient(180deg, #fff 0%, var(--color-bg) 100%);
}

a { color: var(--color-primary); text-underline-offset: 0.18em; }
a:hover, a:focus-visible { color: var(--color-accent); }
img { max-width: 100%; height: auto; }
:focus-visible { outline: 3px solid rgba(15, 118, 110, 0.35); outline-offset: 3px; }

.skip-link {
  position: absolute;
  top: -3rem;
  left: 1rem;
  z-index: 100;
  padding: 0.75rem 1rem;
  border-radius: 0.5rem;
  background: var(--color-primary-strong);
  color: #fff;
}

.skip-link:focus { top: 1rem; }
.container { width: min(100% - 2rem, var(--container-width)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid rgba(217, 226, 236, 0.85);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
}

.site-header__inner, .site-footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 0;
}

.site-brand {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-primary-strong);
  text-decoration: none;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav a {
  display: inline-block;
  padding: 0.55rem 0.85rem;
  border-radius: 999px;
  color: var(--color-text);
  font-weight: 600;
  text-decoration: none;
}

.site-nav a[aria-current="page"], .site-nav a:hover, .site-nav a:focus-visible {
  background: var(--color-surface-muted);
  color: var(--color-primary-strong);
}

.site-main { padding: 2.5rem 0 4rem; }

.content-shell, .page {
  padding: 1.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-surface);
  box-shadow: var(--shadow-soft);
}

.content-shell > :first-child, .page-content > :first-child { margin-top: 0; }
h1, h2, h3 { line-height: 1.2; color: var(--color-primary-strong); }
h1 { font-size: clamp(2rem, 5vw, 3.5rem); margin-bottom: 1rem; }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); margin-top: 2.5rem; }
p, ul, ol { max-width: 68ch; }
section + section { margin-top: 2rem; }

.section-grid {
  display: grid;
  gap: 1.25rem;
}

.surface-card {
  padding: 1.25rem;
  border: 1px solid var(--color-border);
  border-radius: calc(var(--radius) * 0.8);
  background: var(--color-surface-muted);
}

.page-header { margin-bottom: 1.5rem; }
.page-header h1 { margin: 0; }

.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-primary-strong);
  color: rgba(255, 255, 255, 0.9);
}

.site-footer a { color: #fff; }
.site-footer__title, .site-footer__contact p { margin: 0 0 0.35rem; font-weight: 700; }
.site-footer__meta { margin: 0; color: rgba(255, 255, 255, 0.78); }
.site-footer__contact ul { margin: 0; padding: 0; list-style: none; }

@media (max-width: 40rem) {
  .site-header__inner, .site-footer__inner { align-items: flex-start; flex-direction: column; }
  .site-nav { justify-content: flex-start; }
}

@media (min-width: 48rem) {
  .section-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}