style(docs): align Docusaurus theme with fhirworx design system

Replace hacker-dark monospace theme with the editorial palette:
- Playfair Display headings, Source Serif 4 body, JetBrains Mono code
- Light theme: warm off-white (#F7F5F0) + federal navy (#1C2B3A)
- Dark theme: deep navy (#0F1923) + teal accent (#5B8FA8)
- Amber (#C8702A) accent on active sidebar, footer, hero border
- Eyebrow-style breadcrumbs (mono, uppercase, letter-spaced)
- Editorial blockquotes with primary-color left border

docs/src/css/custom.css

@@ -1,59 +1,171 @@
-/* fhirworx design system — matches assets/css/inject.css */
+/* fhirworx design system for Docusaurus
+   Matches the editorial palette from assets/css/fhirworx.css
+   Design: Federal Register Meets Data Journalism */
+
+@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@400;600;700&family=Source+Serif+4:ital,wght@0,300;0,400;0,600;1,400&family=JetBrains+Mono:wght@400;500;600&display=swap');
+
+/* ── Light theme (default) ─────────────────────────────────── */
 
 :root {
-  --ifm-color-primary: #4488dd;
+  --ifm-color-primary: #1C2B3A;
-  --ifm-color-primary-dark: #2d5bb8;
+  --ifm-color-primary-dark: #162230;
-  --ifm-color-primary-darker: #2a56ad;
+  --ifm-color-primary-darker: #131e2a;
-  --ifm-color-primary-darkest: #23478f;
+  --ifm-color-primary-darkest: #0e1620;
-  --ifm-color-primary-light: #4775d1;
+  --ifm-color-primary-light: #253748;
-  --ifm-color-primary-lighter: #527dd4;
+  --ifm-color-primary-lighter: #2d4052;
-  --ifm-color-primary-lightest: #7597dd;
+  --ifm-color-primary-lightest: #3d5570;
-  --ifm-background-color: #0a1628;
+
-  --ifm-font-family-base: "IBM Plex Mono", "Fira Code", "Cascadia Code",
+  --ifm-background-color: #F7F5F0;
-    ui-monospace, monospace;
+  --ifm-background-surface-color: #FAFAF7;
-  --ifm-font-family-monospace: "IBM Plex Mono", "Fira Code", monospace;
+  --ifm-font-color-base: #1A1A18;
-  --ifm-code-font-size: 90%;
+  --ifm-heading-color: #1A1A18;
+  --ifm-link-color: #5B8FA8;
+  --ifm-navbar-background-color: #1C2B3A;
+  --ifm-navbar-link-color: #B8C5D0;
+  --ifm-navbar-link-hover-color: #F7F5F0;
+  --ifm-footer-background-color: #1C2B3A;
+  --ifm-footer-color: #B8C5D0;
+  --ifm-menu-color: #2D2D2B;
+  --ifm-toc-link-color: #6B6B68;
+  --ifm-code-background: #EDEBE6;
+  --ifm-hr-border-color: #D4D0C8;
+
+  --ifm-font-family-base: "Source Serif 4", Georgia, serif;
+  --ifm-font-family-monospace: "JetBrains Mono", "Fira Code", monospace;
+  --ifm-heading-font-family: "Playfair Display", Georgia, serif;
+  --ifm-code-font-size: 88%;
+  --ifm-font-size-base: 16px;
+  --ifm-line-height-base: 1.65;
+
+  --ifm-border-color: #D4D0C8;
+  --ifm-global-radius: 0.2rem;
+
+  --docusaurus-highlighted-code-line-bg: rgba(28, 43, 58, 0.08);
 }
 
+/* ── Dark theme ────────────────────────────────────────────── */
+
 [data-theme="dark"] {
-  --ifm-background-color: #0a1628;
+  --ifm-background-color: #0F1923;
-  --ifm-background-surface-color: #0d1e36;
+  --ifm-background-surface-color: #152231;
-  --ifm-color-primary: #4488dd;
+  --ifm-color-primary: #5B8FA8;
-  --ifm-color-primary-dark: #2d5bb8;
+  --ifm-color-primary-dark: #4C7D96;
-  --ifm-color-primary-darker: #2a56ad;
+  --ifm-color-primary-darker: #47768d;
-  --ifm-color-primary-darkest: #23478f;
+  --ifm-color-primary-darkest: #3b6174;
-  --ifm-color-primary-light: #4775d1;
+  --ifm-color-primary-light: #6BA0B8;
-  --ifm-color-primary-lighter: #527dd4;
+  --ifm-color-primary-lighter: #72A5BC;
-  --ifm-color-primary-lightest: #7597dd;
+  --ifm-color-primary-lightest: #8FB8CC;
-  --ifm-navbar-background-color: #0d1e36;
+
-  --ifm-footer-background-color: #060e1a;
+  --ifm-font-color-base: #EEE9E0;
-  --ifm-font-color-base: #e8e0d4;
+  --ifm-heading-color: #EEE9E0;
-  --ifm-heading-color: #e8e0d4;
+  --ifm-link-color: #7BB8D0;
-  --ifm-link-color: #66aaff;
+  --ifm-navbar-background-color: #0A1219;
-  --ifm-menu-color: #a0b0c8;
+  --ifm-navbar-link-color: #B8C5D0;
-  --ifm-toc-link-color: #a0b0c8;
+  --ifm-footer-background-color: #060D14;
-  --ifm-code-background: #111d30;
+  --ifm-footer-color: #8898A8;
-  --ifm-hr-border-color: #1a2a44;
+  --ifm-menu-color: #B8C5D0;
-  --docusaurus-highlighted-code-line-bg: rgba(51, 102, 204, 0.15);
+  --ifm-toc-link-color: #8898A8;
+  --ifm-code-background: #1A2A3D;
+  --ifm-hr-border-color: #253748;
+  --ifm-border-color: #253748;
+
+  --docusaurus-highlighted-code-line-bg: rgba(91, 143, 168, 0.15);
 }
 
-@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600;700&display=swap");
+/* ── Typography ────────────────────────────────────────────── */
+
+h1, h2, h3, h4, h5, h6 {
+  font-family: var(--ifm-heading-font-family);
+  font-weight: 700;
+  line-height: 1.2;
+  letter-spacing: -0.01em;
+}
+
+.markdown h1:first-child {
+  font-size: 2.2rem;
+}
+
+code, kbd, pre {
+  font-family: var(--ifm-font-family-monospace);
+}
+
+/* ── Navbar ────────────────────────────────────────────────── */
+
+.navbar {
+  box-shadow: none;
+  border-bottom: 1px solid var(--ifm-border-color);
+}
 
 .navbar__title {
+  font-family: var(--ifm-heading-font-family);
   font-weight: 700;
-  letter-spacing: 0.05em;
+  letter-spacing: 0.03em;
+  color: #F7F5F0;
 }
 
+/* ── Sidebar ───────────────────────────────────────────────── */
+
+.menu__link--active:not(.menu__link--sublist) {
+  border-left: 3px solid #C8702A;
+  font-weight: 600;
+}
+
+.menu__link:hover {
+  color: var(--ifm-color-primary);
+}
+
+/* ── Footer ────────────────────────────────────────────────── */
+
 .footer--dark {
-  border-top: 3px solid #ee5577;
+  border-top: 3px solid #C8702A;
 }
 
-/* Red accent bar on hero */
+/* ── Hero / landing ────────────────────────────────────────── */
+
 .hero {
-  border-bottom: 3px solid #ee5577;
+  border-bottom: 3px solid #C8702A;
 }
 
-/* Sidebar active link */
+/* ── Code blocks ───────────────────────────────────────────── */
-.menu__link--active:not(.menu__link--sublist) {
+
-  border-left: 3px solid #ee5577;
+.prism-code {
+  border: 1px solid var(--ifm-border-color);
+  border-radius: var(--ifm-global-radius);
+}
+
+/* ── Breadcrumbs (eyebrow style) ───────────────────────────── */
+
+.breadcrumbs__link {
+  font-family: var(--ifm-font-family-monospace);
+  font-size: 0.75rem;
+  text-transform: uppercase;
+  letter-spacing: 0.1em;
+}
+
+/* ── Table of contents ─────────────────────────────────────── */
+
+.table-of-contents__link--active {
+  color: var(--ifm-color-primary);
+  font-weight: 600;
+}
+
+/* ── Blockquotes (editorial pull-quote style) ──────────────── */
+
+blockquote {
+  border-left: 3px solid var(--ifm-color-primary);
+  background: transparent;
+  font-style: italic;
+}
+
+/* ── Admonitions ───────────────────────────────────────────── */
+
+.alert {
+  border-radius: var(--ifm-global-radius);
+}
+
+/* ── Accent color: amber (#C8702A) for editorial emphasis ──── */
+
+.table-of-contents__link--active,
+.pagination-nav__link:hover {
+  border-color: #C8702A;
 }