:root {
  color-scheme: light;
  --ink: #17201b;
  --muted: #617069;
  --line: rgba(23, 32, 27, 0.14);
  --blue: #315d8f;
  --green: #2f7d57;
  --amber: #a96112;
  --bg: #eef2ef;
  --panel: #fff;
}

* { box-sizing: border-box; }
html, body { min-height: 100%; margin: 0; }
body, button { font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
body { color: var(--ink); background: var(--bg); }
a { color: inherit; text-decoration: none; }
h1, h2, h3, p, dl, dd { margin: 0; letter-spacing: 0; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 64px;
  padding: 10px 24px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
}

.brand { display: grid; }
.brand strong { font-size: 20px; line-height: 1; }
.brand span { margin-top: 3px; color: var(--muted); font-size: 11px; font-weight: 800; }
.site-header nav { display: flex; flex: 1 1 auto; justify-content: flex-end; gap: 4px; min-width: 0; }
.site-header nav a { padding: 8px 11px; border-radius: 7px; color: var(--muted); font-size: 13px; font-weight: 850; }
.site-header nav a.active, .site-header nav a:hover { color: #fff; background: var(--blue); }

.guide-shell { width: min(1180px, 100%); margin: 0 auto; padding: 28px 24px 48px; }
.guide-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; padding-bottom: 24px; }
.guide-heading > div { max-width: 760px; }
.eyebrow { color: var(--muted); font-size: 11px; font-weight: 900; text-transform: uppercase; }
h1 { margin-top: 7px; font-size: 34px; line-height: 1.08; }
h2 { margin-top: 5px; font-size: 22px; line-height: 1.2; }
h3 { font-size: 16px; line-height: 1.25; }
.guide-heading p:last-child { margin-top: 10px; color: var(--muted); font-size: 14px; line-height: 1.55; }
.primary-action, .secondary-action { display: inline-flex; align-items: center; justify-content: center; min-height: 40px; padding: 0 14px; border: 1px solid var(--blue); border-radius: 7px; font-size: 13px; font-weight: 900; }
.primary-action { color: #fff; background: var(--blue); }
.secondary-action { color: var(--blue); background: #fff; }

.reference-strip { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); background: rgba(255, 255, 255, 0.6); }
.reference-strip div { min-width: 0; padding: 16px; border-right: 1px solid var(--line); }
.reference-strip div:last-child { border-right: 0; }
.reference-strip span, .reference-strip strong { display: block; }
.reference-strip span { color: var(--muted); font-size: 10px; font-weight: 900; text-transform: uppercase; }
.reference-strip strong { margin-top: 5px; font-size: 13px; line-height: 1.4; }

.guide-section { padding-top: 30px; }
.section-heading { margin-bottom: 14px; }
.interface-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.interface-item { padding: 18px; border: 1px solid var(--line); border-radius: 8px; background: var(--panel); }
.interface-title { display: flex; align-items: flex-start; justify-content: space-between; gap: 14px; }
.interface-title span { flex: 0 0 auto; max-width: 46%; color: var(--blue); font-size: 11px; font-weight: 900; text-align: right; }
.interface-item dl { display: grid; gap: 8px; margin-top: 16px; }
.interface-item dl div { display: grid; grid-template-columns: 76px minmax(0, 1fr); gap: 10px; }
.interface-item dt { color: var(--muted); font-size: 11px; font-weight: 900; }
.interface-item dd { font-size: 12px; line-height: 1.45; }
.interface-item > p { margin-top: 14px; padding-top: 12px; border-top: 1px solid var(--line); color: var(--amber); font-size: 11px; line-height: 1.45; }

.regional-section { display: grid; grid-template-columns: minmax(250px, 0.7fr) minmax(0, 1.3fr); gap: 28px; align-items: start; }
.regional-notes { display: grid; gap: 1px; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; background: var(--line); }
.regional-notes p { padding: 13px 15px; background: #fff; font-size: 12px; line-height: 1.5; }

.ordering-band { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 24px 0 0; margin-top: 30px; border-top: 1px solid var(--line); }
.ordering-band h2 { max-width: 780px; }

@media (max-width: 760px) {
  .site-header { padding: 10px 14px; }
  .site-header nav { justify-content: flex-start; overflow-x: auto; }
  .site-header nav a { padding: 7px 8px; white-space: nowrap; font-size: 12px; }
  .guide-shell { padding: 20px 14px 36px; }
  .guide-heading, .ordering-band { align-items: flex-start; flex-direction: column; }
  h1 { font-size: 29px; }
  .reference-strip, .interface-grid, .regional-section { grid-template-columns: 1fr; }
  .reference-strip div { border-right: 0; border-bottom: 1px solid var(--line); }
  .reference-strip div:last-child { border-bottom: 0; }
  .interface-title { display: grid; }
  .interface-title span { max-width: none; text-align: left; }
}