/*
 * SHARED THEME
 *
 * Generic styles shared across our websites, loaded after reset.css.
 * Includes theme settings, base typography and reusable utilities.
 * Single page is the default content layout; Post adds article-specific structure.
 *
 * The :root section defines CSS custom properties (variables).
 * Rules reference these with var(), for example:
 * color: var(--color-primary).
 *
 * Changing a variable updates every rule that uses it.
 * Individual websites can override these variables in site.css,
 * which loads after this stylesheet.
 *
 * This file must remain independent of any particular website
 * or demo page so it can be distributed through the shared gem.
 */

/* Theme settings */
:root {
  --font-body: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-heading: var(--font-body);
  --font-brand: var(--font-body);
  --font-code: ui-monospace, monospace;

  --font-size-body: 1rem;
  --font-size-brand: 1.25rem;
  --font-size-lead: 1.25rem;
  --font-size-small: 0.875rem;
  --font-size-h1: clamp(2rem, 1.5rem + 2vw, 3rem);
  --font-size-h2: clamp(1.75rem, 1.5rem + 1vw, 2.25rem);
  --font-size-h3: 1.5rem;
  --font-size-h4: 1.25rem;
  --font-size-h5: 1.125rem;
  --font-size-h6: 1rem;

  --line-height-body: 1.6;
  --line-height-heading: 1.2;
  --line-height-heading-small: 1.3;
  --font-weight-body: 400;
  --font-weight-heading: 700;
  --font-weight-bold: 700;

  --color-background: #ffffff;
  --color-text: #202124;
  --color-muted: #595f69;
  --color-primary: #2457d6;
  --color-border: #dfe3e8;
  --color-surface: #f4f5f7;
  --color-control-border: #858b95;
  --color-danger: #b42318;
  --color-on-primary: #ffffff;
  --color-on-danger: #ffffff;
  --form-radius: 0.375rem;
  --form-control-padding: 0.75rem;
  --form-field-gap: var(--space-6);
  --color-footer-background: #ffffff;
  --color-footer-text: #000000;

  --admin-sidebar-width: 11.25rem;
  --auth-width: 26rem;
  --single-page-width: 70ch;
  --landing-page-content-width: 70ch;
  --landing-page-wide-width: 72rem;
  --post-content-width: 45rem;
  --post-width: 72.75rem;
  --posts-width: 72.75rem;
  --font-posts-links: Georgia, "Times New Roman", serif;
  --post-sidebar-width: 18rem;
  --page-width: 72rem; /* Footer content width. */
  --page-padding: clamp(1rem, 4vw, 3rem);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
}

/* Document foundation */
body {
  font-family: var(--font-body);
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
  font-weight: var(--font-weight-body);
  color: var(--color-text);
  background: var(--color-background);
}

/* Single page: the default content layout at every screen size. */
.single-page {
  width: calc(100% - 2 * var(--page-padding));
  max-width: min(var(--single-page-width), 50rem);
  margin-inline: auto;
  padding-block: var(--space-12);
  overflow-wrap: anywhere;
}

.single-page__header {
  margin-block-end: var(--space-8);
}

/* Landing page: centred reading sections with optional wider sections.
 * Width modifiers belong on direct children of the main wrapper. */
.landing-page {
  width: calc(100% - 2 * var(--page-padding));
  max-width: var(--landing-page-wide-width);
  margin-inline: auto;
  padding-block: var(--space-12);
  display: grid;
  gap: var(--space-12);
  overflow-wrap: anywhere;
}

.landing-page > * {
  box-sizing: border-box;
  width: 100%;
  max-width: var(--landing-page-content-width);
  min-width: 0;
  margin-inline: auto;
  margin-block: 0;
}

.landing-page > .landing-page__wide {
  max-width: none;
}

.landing-page__hero {
  text-align: center;
}

/* Authentication: a narrow form centred in the available page area. */
.auth-shell {
  display: flex;
  flex-direction: column;
  min-height: 100svh;
}

.auth-shell > .site-footer { margin-block-start: 0; }

.auth-page {
  display: grid;
  place-items: center;
  flex: 1;
  width: 100%;
  padding: var(--space-12) var(--page-padding);
  overflow-wrap: anywhere;
}

.auth-page__content {
  width: 100%;
  max-width: var(--auth-width);
  min-width: 0;
}

.auth-page__header {
  margin-block-end: var(--space-8);
  text-align: center;
}

.auth-page__header h1 { font-size: var(--font-size-h2); }
.auth-page__header p { margin-bottom: 0; color: var(--color-muted); }
.auth-page__submit { width: 100%; }
.auth-page__links { margin-block: var(--space-6) 0; text-align: center; }
.auth-page__note { margin-block: var(--space-6) 0; text-align: center; }

/* Post: article and supporting author information. */
.post {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
  gap: clamp(2rem, 4vw, 4rem);
  width: calc(100% - 2 * var(--page-padding));
  max-width: var(--post-width);
  margin-inline: auto;
  padding-block: clamp(1rem, 2vw, 2rem) clamp(3rem, 8vw, 7.5rem);
  overflow-wrap: anywhere;
}

.post > * {
  min-width: 0;
}

.post__article,
.post__sidebar,
.post__author {
  max-width: var(--post-content-width);
}

.post__header {
  padding-block-end: var(--space-6);
}

.post__toc {
  margin-block: var(--space-6) var(--space-12);
}

.post__toc li + li {
  margin-block-start: 0;
}

.post__meta,
.post__breadcrumbs {
  font-size: var(--font-size-small);
}

.post__meta,
.post__breadcrumbs {
  color: var(--color-muted);
}

.post__breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  list-style: none;
  margin: 0;
  padding: 0;
}

.post__breadcrumbs li {
  margin: 0;
}

.post__breadcrumbs .post__separator {
  margin-inline-end: var(--space-2);
}

.post__toc h2 {
  font-size: var(--font-size-h3);
}

/* post__author remains supported for existing single-block sidebars. */
.post__sidebar,
.post__author {
  font-size: 0.9375rem;
  line-height: 1.6;
}

:is(.post__sidebar, .post__author) h2 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: var(--font-weight-bold);
  line-height: 1.2;
  color: var(--color-text);
  letter-spacing: normal;
  text-transform: none;
}

.post__sidebar-section > *,
.post__author > :is(p, ul, ol) {
  margin-block: 0;
}

.post__sidebar-section > * + *,
.post__author > * + * {
  margin-block-start: var(--space-3);
}

.post__sidebar-section > .form {
  margin-block-start: var(--space-4);
}

:where(.post__sidebar, .post__author) > .post__sidebar-section + .post__sidebar-section {
  margin-block-start: var(--space-12);
  padding-block-start: var(--space-6);
  border-block-start: 1px solid var(--color-border);
}

.post__body > section + section {
  margin-block-start: var(--space-8);
}

/* Opt in by adding post--drop-cap to the main Post wrapper. */
.post--drop-cap .post__body > p:first-child::first-letter {
  float: left;
  font-size: 3.5em;
  font-weight: var(--font-weight-bold);
  line-height: 0.9;
  margin-block-start: 0.08em;
  margin-inline-end: 0.12em;
}

/* Headings */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  line-height: var(--line-height-heading);
  font-weight: var(--font-weight-heading);
  margin-bottom: var(--space-4);
}

h1 {
  font-size: var(--font-size-h1);
}

h2 {
  font-size: var(--font-size-h2);
}

h3 {
  font-size: var(--font-size-h3);
}

h4 {
  font-size: var(--font-size-h4);
}

h5 {
  font-size: var(--font-size-h5);
}

h6 {
  font-size: var(--font-size-h6);
}

h3,
h4,
h5,
h6 {
  line-height: var(--line-height-heading-small);
}

/* Separate topics after prose, keeping consecutive headings together. */
.prose > :is(p, ul, ol, dl, blockquote, pre):not(.eyebrow) + :is(h1, h2, h3, h4, h5, h6) {
  margin-block-start: var(--space-8);
}

/* Text */
p,
ul,
ol,
dl,
blockquote,
pre {
  margin-bottom: var(--space-4);
}

.lead {
  font-size: var(--font-size-lead);
}

small {
  font-size: var(--font-size-small);
}

strong,
b {
  font-weight: var(--font-weight-bold);
}

.text-muted {
  color: var(--color-muted);
}

.eyebrow {
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-bold);
  color: var(--color-muted);
}

/* Apply to numeric table headers and cells. */
.numeric-cell {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* Responsive images: display and max-width are supplied by reset.css. */
img {
  height: auto;
}

/* Figures may contain images, quotes or other self-contained content. */
figure {
  margin-block: var(--space-8);
  margin-inline: 0;
}

figcaption {
  margin-block-start: var(--space-2);
  color: var(--color-muted);
  font-size: var(--font-size-small);
  line-height: var(--line-height-body);
  overflow-wrap: anywhere;
}

/* Optional gallery: stacked on mobile, preserving each image's proportions. */
.image-gallery {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-6);
  margin-block: var(--space-8);
}

.image-gallery > figure {
  min-width: 0;
  margin: 0;
}

/* Support direct images, linked images and responsive picture elements. */
.image-gallery > figure > :is(a, picture),
.image-gallery > figure > a > picture {
  display: block;
}

.image-gallery > figure > img,
.image-gallery > figure > :is(a, picture) > img,
.image-gallery > figure > a > picture > img {
  width: 100%;
}

/* Opt-in video embeds: HTML dimensions remain useful fallbacks without CSS. */
iframe.content-embed {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  border: 0;
  margin-block: var(--space-8);
}

/* Links and keyboard focus */
a {
  color: var(--color-primary);
  text-underline-offset: 0.2em;
}

:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 3px;
}

/* Lists */
ul,
ol {
  padding-inline-start: var(--space-6);
}

li + li {
  margin-top: var(--space-2);
}

li > :is(ul, ol) {
  margin-top: var(--space-2);
  margin-bottom: 0;
}

dt {
  font-weight: var(--font-weight-bold);
}

dd {
  margin-bottom: var(--space-4);
}

/* Quotes and separators */
blockquote {
  padding-inline-start: var(--space-6);
  border-inline-start: 4px solid var(--color-muted);
}

blockquote footer {
  color: var(--color-muted);
}

hr {
  border: 0;
  border-top: 1px solid var(--color-border);
  margin-block: var(--space-8);
}

/* Code */
code,
pre {
  font-family: var(--font-code);
}

pre {
  padding: var(--space-4);
  background: var(--color-surface);
  overflow-x: auto;
}

/* Forms: opt in with .form; standalone fields can use .form-field. */
.form {
  display: grid;
  gap: var(--form-field-gap);
}

.form fieldset {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.form legend {
  padding: 0;
  margin-block-end: var(--space-4);
  font-weight: var(--font-weight-bold);
}

.form fieldset > .form-field + .form-field {
  margin-block-start: var(--form-field-gap);
}

.form-field {
  display: grid;
  align-content: start;
  gap: var(--space-2);
  min-width: 0;
}

.form-field > label {
  font-weight: var(--font-weight-bold);
}

/* Explicit types preserve native checkbox, file, range and colour controls. */
:where(.form, .form-field) :is(input:not([type]), input[type="text"], input[type="email"], input[type="password"], input[type="search"], input[type="url"], input[type="tel"], input[type="number"], input[type="date"], input[type="datetime-local"], input[type="month"], input[type="week"], input[type="time"], select, textarea) {
  box-sizing: border-box;
  width: 100%;
  min-width: 0;
  min-height: 3rem;
  padding: var(--form-control-padding);
  color: var(--color-text);
  background-color: var(--color-background);
  border: 1px solid var(--color-control-border);
  border-radius: var(--form-radius);
  font: inherit;
  line-height: 1.5;
}

:where(.form, .form-field) textarea {
  min-height: 8rem;
  resize: vertical;
}

:where(.form, .form-field) :is(input, textarea)::placeholder {
  color: var(--color-muted);
  opacity: 1;
}

:where(.form, .form-field) :is(input, select, textarea):focus {
  border-color: var(--color-primary);
  outline: 3px solid var(--color-primary);
  outline-offset: 3px;
}

/* Validation is application-controlled; untouched required fields stay neutral. */
:where(.form, .form-field) [aria-invalid="true"] {
  border-color: var(--color-danger);
}

:where(.form, .form-field) :is(input, textarea)[readonly] {
  background-color: var(--color-surface);
}

:where(.form, .form-field) :is(input, select, textarea):disabled {
  color: var(--color-muted);
  background-color: var(--color-surface);
  cursor: not-allowed;
  opacity: 1;
}

.form-help,
.form-error {
  display: block;
  margin: 0;
  font-size: var(--font-size-small);
}

.form-help { color: var(--color-muted); }
.form-error { color: var(--color-danger); }

.form-choice,
.form-field > label:has(input:is([type="checkbox"], [type="radio"])) {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  min-height: 2.75rem;
  padding-block: var(--space-2);
  font-weight: var(--font-weight-body);
  cursor: pointer;
}

:where(.form, .form-field) input:is([type="checkbox"], [type="radio"]) {
  width: 1.125rem;
  height: 1.125rem;
  flex-shrink: 0;
  accent-color: var(--color-primary);
}

.form-choice:has(:disabled) { color: var(--color-muted); cursor: not-allowed; }

:where(.form, .form-field) input[type="range"] {
  width: 100%;
  min-height: 2.75rem;
  accent-color: var(--color-primary);
}

:where(.form, .form-field) input[type="file"] {
  width: 100%;
  min-width: 0;
  padding: var(--space-2);
  border: 1px solid var(--color-control-border);
  border-radius: var(--form-radius);
  color: var(--color-muted);
}

:where(.form, .form-field) input[type="file"]::file-selector-button {
  margin-inline-end: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border: 0;
  border-radius: calc(var(--form-radius) / 2);
  background: var(--color-surface);
  color: var(--color-text);
  font: inherit;
  cursor: pointer;
}

.form-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--form-field-gap);
}

.form-field--short { max-width: 12rem; }

.button-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 3rem;
  padding: var(--space-3) var(--space-6);
  border: 1px solid transparent;
  border-radius: var(--form-radius);
  background: var(--color-primary);
  color: var(--color-on-primary);
  font: inherit;
  font-weight: var(--font-weight-bold);
  line-height: 1.5;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
}

.button--secondary { background: var(--color-surface); color: var(--color-text); border-color: var(--color-muted); }
.button--outline { background: transparent; color: var(--color-primary); border-color: currentColor; }
.button--danger { background: var(--color-danger); color: var(--color-on-danger); }
.button--small { padding: var(--space-2) var(--space-4); min-height: 2.75rem; font-size: var(--font-size-small); }
.button--large { padding: var(--space-4) var(--space-8); font-size: var(--font-size-lead); }
.button:hover:not(:disabled) { text-decoration: underline; text-underline-offset: 0.2em; }
.button:active:not(:disabled) { transform: translateY(1px); }
.button:disabled { background: var(--color-surface); color: var(--color-muted); border-color: var(--color-border); cursor: not-allowed; }

@media (min-width: 40em) {
  .form-row { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* Full-width site header and primary navigation */
.site-header {
  width: 100%;
}

.site-header__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4) var(--space-8);
  padding: var(--space-4) var(--page-padding);
}

.site-brand {
  font-family: var(--font-brand);
  font-size: var(--font-size-brand);
  font-weight: normal;
  color: var(--color-text);
  text-decoration: none;
}

.site-nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: var(--space-2);
  color: var(--color-text);
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: 0.25rem;
  cursor: pointer;
}

.site-nav-toggle[hidden] {
  display: none;
}

.site-nav {
  flex-basis: 100%;
}

/* Without JavaScript, the toggle stays hidden and all links remain available. */
.site-nav-toggle:not([hidden])[aria-expanded="false"] + .site-nav {
  display: none;
}

.site-nav__list {
  display: flex;
  flex-direction: column;
  flex-wrap: wrap;
  align-items: stretch;
  gap: var(--space-3) var(--space-6);
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav__list > li {
  margin: 0;
}

.site-nav__list a {
  display: block;
  padding-block: var(--space-2);
}

.site-nav__dropdown {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
}

.site-nav__dropdown-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 24px;
  min-width: 24px;
  flex-shrink: 0;
  min-height: 44px;
  padding: var(--space-2) 0;
  color: var(--color-text);
  background: transparent;
  border: 0;
  cursor: pointer;
}

.site-nav__dropdown-toggle[aria-expanded="true"] svg {
  transform: rotate(90deg);
}

.site-nav__dropdown > .site-nav__submenu {
  flex-basis: 100%;
  list-style: none;
  margin: 0;
  padding-inline-start: var(--space-6);
}

.site-nav__submenu > li {
  margin: 0;
}

/* Grouped site footer */
.site-footer {
  width: 100%;
  margin-block-start: var(--space-12);
  color: var(--color-footer-text);
  background: var(--color-footer-background);
  border-block-start: 1px solid var(--color-border);
}

.site-footer__inner {
  max-width: var(--page-width);
  margin-inline: auto;
  padding: var(--space-12) var(--page-padding);
}

.site-footer__nav {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-8);
}

.site-footer__heading {
  margin-block-end: var(--space-3);
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-bold);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-footer__links {
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-footer__links > li {
  margin: 0;
}

.site-footer__links a {
  display: inline-block;
  padding-block: var(--space-2);
  color: inherit;
  font-size: var(--font-size-small);
  font-weight: normal;
  text-decoration: none;
  overflow-wrap: anywhere;
}

.site-footer__links a:hover,
.site-footer__links a:focus-visible {
  text-decoration: underline;
}

.site-footer a:focus-visible {
  outline-color: currentColor;
}

/* Shared cards; spacing between cards belongs to their containing layout. */
.card {
  padding: var(--space-6);
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
}

.card--surface {
  background: var(--color-surface);
  border-color: var(--color-control-border);
}

/* Posts: a topic directory matching the reference Articles index. */
.posts {
  width: calc(100% - 2 * var(--page-padding));
  max-width: var(--posts-width);
  margin-inline: auto;
  padding-block: clamp(1rem, 2vw, 2rem) clamp(3rem, 8vw, 7.5rem);
  overflow-wrap: anywhere;
}

.posts__header {
  display: grid;
  justify-items: center;
  gap: 2rem;
  max-width: 60rem;
  margin-inline: auto;
  padding-block: clamp(2.5rem, 7vw, 5rem) clamp(4rem, 9vw, 7rem);
  text-align: center;
}

.posts__header h1,
.posts__header p {
  margin: 0;
}

.posts__header h1 {
  font-size: clamp(2rem, 4vw, 2.5rem);
}

.posts__header p {
  max-width: 42rem;
  font-family: var(--font-posts-links);
  font-size: clamp(1.125rem, 2vw, 1.25rem);
}

.posts__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(3rem, 7vw, 6rem);
}

.posts__category {
  min-width: 0;
}

.posts__category h2 {
  margin: 0;
  padding-block-end: 0.75rem;
  font-size: 1.25rem;
}

.posts__category a {
  color: inherit;
  text-decoration: none;
}

.posts__category a:hover,
.posts__category a:focus-visible {
  text-decoration: underline;
}

.posts__category ul {
  padding: 0;
  margin: 0;
  list-style: none;
}

.posts__category li {
  margin: 0;
}

.posts__category li a {
  display: flex;
  align-items: center;
  min-height: 3.625rem;
  font-family: var(--font-posts-links);
  font-size: 1.125rem;
  line-height: 1.35;
}

.posts__more {
  display: inline-flex;
  align-items: center;
  gap: 1.5rem;
  min-height: 3.5rem;
  font-size: 0.75rem;
  font-weight: var(--font-weight-bold);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* Posts list: opt in per page with main.posts.posts--list. */
.posts--list {
  max-width: var(--post-content-width);
}

.posts--list .posts__header {
  justify-items: start;
  gap: var(--space-4);
  padding-block: var(--space-8) var(--space-12);
  text-align: left;
}

.posts--list .posts__header p {
  font-family: var(--font-body);
}

.posts--list .posts__list {
  display: grid;
  gap: var(--space-6);
  list-style: none;
  padding: 0;
  margin: 0;
}

.posts--list .posts__item {
  margin: 0;
}

.posts--list .posts__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2) var(--space-4);
  margin: 0 0 var(--space-2);
  color: var(--color-muted);
  font-size: var(--font-size-small);
}

.posts--list .posts__title {
  margin: 0 0 var(--space-3);
  font-size: var(--font-size-h3);
}

.posts--list .posts__title a {
  color: inherit;
  text-decoration: none;
}

.posts--list .posts__title a:hover,
.posts--list .posts__title a:focus-visible {
  text-decoration: underline;
}

.posts--list .posts__excerpt { margin: 0; }

/* Shared responsive breakpoints
 * Base rules above apply at every width, starting with small screens.
 * Add component overrides below as responsive layouts are introduced.
 * These minimum-width queries accumulate: wide screens match all three.
 * Pixel equivalents assume a browser default font size of 16px.
 */

/* Medium: 40em (usually 640px) */
@media (min-width: 40em) {
  .image-gallery {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .site-footer__nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* Posts matches the reference directory's 48rem column breakpoint. */
@media (min-width: 48rem) {
  .posts__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(3rem, 8vw, 8.5rem);
  }
}

/* Large: 60em (usually 960px) */
@media (min-width: 60em) {
  .site-nav__dropdown-toggle:not([hidden]) {
    display: inline-flex;
  }

  /* Without a connected controller, nested links stay visible in normal flow. */
  .site-nav__dropdown-toggle:not([hidden]) + .site-nav__submenu {
    position: absolute;
    z-index: 10;
    inset-block-start: 100%;
    inset-inline-end: 0;
    min-width: 12rem;
    max-width: calc(100vw - 2 * var(--page-padding));
    padding: var(--space-2);
    background: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: 0.25rem;
    box-shadow: 0 0.5rem 1.5rem rgb(0 0 0 / 0.1);
  }

  .site-nav__dropdown-toggle:not([hidden])[aria-expanded="false"] + .site-nav__submenu {
    display: none;
  }

  .site-nav__submenu a {
    padding-inline: var(--space-3);
    overflow-wrap: anywhere;
  }

  .site-nav__submenu a:hover,
  .site-nav__submenu a:focus-visible {
    background: var(--color-surface);
  }

  .site-footer__nav {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .site-nav-toggle {
    display: none;
  }

  .site-nav {
    flex-basis: auto;
  }

  .site-nav-toggle:not([hidden])[aria-expanded="false"] + .site-nav {
    display: block;
  }

  .site-nav__list {
    flex-direction: row;
    align-items: center;
  }
}

/* Post matches the reference article's 64rem sidebar breakpoint. */
@media (min-width: 64rem) {
  .post {
    grid-template-columns: minmax(0, var(--post-content-width)) minmax(16rem, var(--post-sidebar-width));
    justify-content: space-between;
    column-gap: clamp(2rem, 6vw, 6rem);
  }
}

/* Wide: 80em (usually 1280px) */
@media (min-width: 80em) {
  /* Shared wide-screen component overrides. */
}

/* Social links */
.social-links {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.social-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.social-link svg {
  display: block;
  flex-shrink: 0;
}

/* Admin: full-width workspace below the existing site header. */
.admin-shell {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.admin-layout {
  flex: 1;
  width: 100%;
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-content: start;
}

.admin-sidebar {
  padding: var(--space-4) var(--space-3);
  border-block-end: 1px solid var(--color-border);
  min-width: 0;
}

.admin-menu-toggle {
  min-height: 44px;
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--form-radius);
  background: var(--color-background);
  color: var(--color-text);
  font: inherit;
  cursor: pointer;
}

.admin-menu-toggle[hidden] { display: none; }
.admin-menu-toggle:not([hidden])[aria-expanded="false"] + .admin-nav { display: none; }
.admin-menu-toggle:not([hidden])[aria-expanded="true"] + .admin-nav { margin-block-start: var(--space-3); }

.admin-nav__list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: var(--space-1);
}

.admin-nav__list > li { margin: 0; }
.admin-nav__link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-height: 44px;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--form-radius);
  color: var(--color-muted);
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-bold);
  text-decoration: none;
  overflow-wrap: anywhere;
}

.admin-nav__link svg { width: 1.125rem; height: 1.125rem; flex: none; }
.admin-nav__link:hover,
.admin-nav__link[aria-current="page"] {
  background: var(--color-surface);
  color: var(--color-text);
  text-decoration: none;
}

.admin-content {
  min-width: 0;
  padding: var(--space-6);
  overflow-wrap: anywhere;
}

@media (min-width: 60em) {
  .admin-layout {
    grid-template-columns: var(--admin-sidebar-width) minmax(0, 1fr);
    align-content: stretch;
  }
  .admin-sidebar {
    border-block-end: 0;
    border-inline-end: 1px solid var(--color-border);
  }
  .admin-menu-toggle { display: none; }
  .admin-menu-toggle:not([hidden])[aria-expanded="false"] + .admin-nav { display: block; }
  .admin-menu-toggle:not([hidden])[aria-expanded="true"] + .admin-nav { margin-block-start: 0; }
}