:root {
  --bg: #FDFEFD;
  --ink: #0B1A3C;
  --navy: #163A66;
  --yellow: #FFE000;
  --peach: #FFBC7D;
  --muted: #7A7A7A;
  --rule: #E5E7EB;
  --footer-bg: #0B1A3C;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Montserrat", system-ui, -apple-system, "Segoe UI", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--navy); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--rule);
  position: sticky;
  top: 0;
  z-index: 10;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.wordmark {
  font-weight: 800;
  font-size: 22px;
  color: var(--navy);
  text-decoration: none;
  letter-spacing: 0.5px;
}
.back-link {
  font-size: 14px;
  color: var(--muted);
  text-decoration: none;
}
.back-link:hover { color: var(--navy); }

/* Hero */
.hero { padding: 64px 0 32px; }
.hero h1 {
  font-size: 40px;
  font-weight: 700;
  color: var(--navy);
  margin: 0 0 8px;
  letter-spacing: -0.5px;
}
.hero .meta {
  color: var(--muted);
  font-size: 14px;
  margin: 0 0 24px;
}
.banner {
  background: var(--peach);
  color: var(--ink);
  padding: 16px 20px;
  border-radius: 6px;
  font-size: 15px;
  line-height: 1.55;
}
.banner strong { color: var(--navy); }

/* Reading column inside hero */
.reading-column { max-width: 720px; }

/* Body grid: two-col on desktop, single on mobile */
.body-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  padding-top: 16px;
  padding-bottom: 64px;
}
@media (min-width: 1024px) {
  .body-grid {
    grid-template-columns: 240px minmax(0, 720px);
    align-items: start;
  }
}

/* Table of contents */
.toc {
  font-size: 14px;
}
.toc-label {
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 600;
  color: var(--muted);
  font-size: 12px;
  margin: 0 0 12px;
}
.toc ol {
  margin: 0;
  padding-left: 20px;
}
.toc li { margin: 6px 0; }
.toc a { color: var(--navy); text-decoration: none; }
.toc a:hover { text-decoration: underline; }
@media (min-width: 1024px) {
  .toc {
    position: sticky;
    top: 80px;
  }
}

/* Article */
.prose section { padding-top: 32px; }
.prose section:first-child { padding-top: 0; }

.prose h2 {
  font-size: 26px;
  font-weight: 700;
  color: var(--navy);
  margin: 0 0 8px;
  letter-spacing: -0.2px;
}
.prose h2::before {
  content: "";
  display: block;
  width: 48px;
  height: 4px;
  background: var(--yellow);
  margin-bottom: 16px;
}

.prose h3 {
  font-size: 19px;
  font-weight: 600;
  color: var(--navy);
  margin: 24px 0 8px;
}

.prose p { margin: 0 0 16px; }
.prose ul { margin: 0 0 16px; padding-left: 22px; }
.prose ul li { margin: 6px 0; }

.prose code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.95em;
  background: #F1F3F5;
  padding: 1px 6px;
  border-radius: 4px;
}

.address { color: var(--ink); }

/* Footer */
.site-footer {
  background: var(--footer-bg);
  color: #fff;
  padding: 48px 0;
  margin-top: 64px;
  text-align: center;
  font-size: 14px;
}
.site-footer p { margin: 4px 0; }
.site-footer a { color: #fff; }

/* Mobile tweaks */
@media (max-width: 640px) {
  body { font-size: 16px; }
  .hero { padding: 40px 0 24px; }
  .hero h1 { font-size: 32px; }
  .prose h2 { font-size: 22px; }
  .container { padding: 0 20px; }
}