/*
Theme Name: Stem Cell Authority
Theme URI: https://example.com/stem-cell-authority
Author: Web Agency
Author URI: https://example.com
Description: Editorial WordPress theme for stem cell and regenerative medicine content publication. Modern, clean, sustained-reading typography. Author, category, and tag display suppressed by design. WCAG 2.2 AA. Lightweight classic theme, plug-and-play.
Version: 1.0.0
Requires at least: 5.8
Tested up to: 6.9
Requires PHP: 7.4
License: GPL v2 or later
License URI: https://www.gnu.org/licenses/gpl-2.0.html
Text Domain: stem-cell-authority
Tags: blog, two-columns, right-sidebar, custom-menu, custom-logo, featured-images, footer-widgets, threaded-comments, translation-ready, accessibility-ready
*/

/* ==========================================================
   STEM CELL AUTHORITY · Editorial classic theme
   v1.0.0 · WCAG 2.2 AA · Em dash 0
   3-breakpoint: ≤767 mobile / 768-1279 tablet / ≥1280 desktop
   ========================================================== */

:root {
  --ink: #1a1d24;
  --ink-soft: #3a4150;
  --ink-faded: #5a6779;
  --paper: #fafaf7;
  --paper-deep: #f3f3ee;
  --rule: #dcdcd5;
  --rule-strong: #b8b8af;
  --accent: #a08866;
  --supportive: #5a6779;

  --serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  --sans: 'Inter', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;

  --container: 1180px;
  --reading: 720px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}

* { box-sizing: border-box; }

html {
  font-size: 17px;
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--ink);
  background: var(--paper);
  font-feature-settings: "kern", "liga", "onum";
  font-variant-numeric: oldstyle-nums proportional-nums;
}

/* Skip link */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: var(--paper);
  padding: 0.5rem 1rem;
  font-family: var(--sans);
  font-size: 0.875rem;
  z-index: 1000;
  text-decoration: none;
}
.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

.screen-reader-text {
  border: 0;
  clip: rect(1px, 1px, 1px, 1px);
  clip-path: inset(50%);
  height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  width: 1px;
  word-wrap: normal !important;
}
.screen-reader-text:focus {
  clip-path: none;
  background-color: var(--ink);
  color: var(--paper);
  padding: 1rem;
  z-index: 100000;
}

/* Focus visible (WCAG 2.4.7) */
:where(a, button, input, select, textarea, [tabindex]):focus {
  outline: none;
}
:where(a, button, input, select, textarea, [tabindex]):focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ==========================================================
   TYPOGRAPHY
   ========================================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--serif);
  font-weight: 500;
  letter-spacing: -0.012em;
  margin-top: 0;
  line-height: 1.2;
  color: var(--ink);
  text-wrap: balance;
}

h1 { font-size: clamp(1.875rem, 4vw, 2.625rem); line-height: 1.15; letter-spacing: -0.018em; }
h2 { font-size: clamp(1.5rem, 2.5vw, 1.875rem); }
h3 { font-size: clamp(1.25rem, 2vw, 1.5rem); line-height: 1.3; }
h4 { font-family: var(--sans); font-weight: 600; font-size: 1.125rem; letter-spacing: 0; }

p {
  margin-block: 1rem;
  text-wrap: pretty;
}

a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--rule-strong);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}
a:hover {
  color: var(--accent);
  text-decoration-color: var(--accent);
}

blockquote {
  margin: 2rem 0;
  padding-left: 1.25rem;
  border-left: 3px solid var(--rule-strong);
  font-style: italic;
  color: var(--ink-soft);
}

ul, ol {
  padding-left: 1.5rem;
}

li {
  margin-block: 0.4rem;
}

img {
  max-width: 100%;
  height: auto;
}

figure {
  margin: 2rem 0;
}

figcaption {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--ink-faded);
  text-align: center;
  margin-top: 0.5rem;
}

hr {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 2.5rem 0;
}

/* ==========================================================
   LAYOUT WRAPPERS
   ========================================================== */

.container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 1.5rem;
}

.container--reading {
  max-width: var(--reading);
}

/* ==========================================================
   HEADER
   ========================================================== */

.site-header {
  border-bottom: 1px solid var(--rule);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
  background: rgba(250, 250, 247, 0.96);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  padding-block: 1.25rem;
}

.site-branding {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.site-tagline {
  font-family: var(--sans);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faded);
  margin: 0;
  line-height: 1;
}

.site-title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.25rem, 2vw, 1.625rem);
  letter-spacing: -0.012em;
  margin: 0;
  line-height: 1.1;
}
.site-title a {
  color: var(--ink);
  text-decoration: none;
}

.site-logo img {
  max-height: 48px;
  width: auto;
}

/* Primary nav */
.primary-nav {
  font-family: var(--sans);
  font-size: 0.92rem;
  font-weight: 500;
}

.primary-nav ul {
  list-style: none;
  display: flex;
  gap: 1.75rem;
  margin: 0;
  padding: 0;
}

.primary-nav a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color 0.15s, border-color 0.15s;
}

.primary-nav a:hover,
.primary-nav .current-menu-item > a,
.primary-nav .current_page_item > a {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

.primary-nav .sub-menu {
  display: none;
  position: absolute;
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 0.5rem 0;
  min-width: 200px;
  margin-top: 0.5rem;
  z-index: 100;
}

.primary-nav li:hover > .sub-menu,
.primary-nav li:focus-within > .sub-menu {
  display: block;
}

.primary-nav .sub-menu li {
  margin: 0;
}

.primary-nav .sub-menu a {
  display: block;
  padding: 0.5rem 1rem;
  border-bottom: none;
}

.primary-nav .sub-menu a:hover {
  background: var(--paper-deep);
  color: var(--accent);
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--rule-strong);
  padding: 0.5rem 1rem;
  font-family: var(--sans);
  font-size: 0.85rem;
  cursor: pointer;
  color: var(--ink);
}

/* ==========================================================
   MAIN CONTENT
   ========================================================== */

.site-main {
  padding-block: 3rem 4rem;
}

/* Page header (archive, search, 404) */
.page-header {
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--rule);
}

.page-header__kicker {
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.5rem;
}

.page-title {
  margin-block: 0 0.75rem;
}

.archive-description {
  color: var(--ink-soft);
  font-size: 1.125rem;
  max-width: 60ch;
  margin: 0;
}

/* ==========================================================
   ARTICLE LIST + CARDS
   ========================================================== */

.article-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 2.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.article-card {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  padding: 1.5rem 0 0;
  border-top: 1px solid var(--rule);
}

.article-card__date {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--ink-faded);
  text-transform: uppercase;
}

.article-card__title {
  margin: 0;
  font-size: 1.25rem;
  line-height: 1.3;
  letter-spacing: -0.012em;
}
.article-card__title a {
  text-decoration: none;
  color: var(--ink);
}
.article-card__title a:hover {
  color: var(--accent);
}

.article-card__excerpt {
  margin: 0;
  color: var(--ink-soft);
  font-size: 1rem;
  line-height: 1.55;
}

.article-card__more {
  font-family: var(--sans);
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
  padding-bottom: 1px;
  display: inline-block;
  margin-top: 0.25rem;
  align-self: flex-start;
}

.article-card__more:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* Featured (first article on home) */
.article-card--featured {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 3rem;
  padding: 0 0 2.5rem;
  border-top: none;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 1rem;
}

.article-card--featured .article-card__title {
  font-size: clamp(1.625rem, 3vw, 2.25rem);
  line-height: 1.2;
}

.article-card--featured .article-card__excerpt {
  font-size: 1.125rem;
  line-height: 1.6;
}

/* ==========================================================
   PAGINATION
   ========================================================== */

.pagination {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.875rem;
}

.pagination .nav-links {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.pagination a,
.pagination .page-numbers {
  color: var(--ink);
  text-decoration: none;
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid transparent;
}

.pagination a:hover {
  border-bottom-color: var(--accent);
  color: var(--accent);
}

.pagination .current {
  font-weight: 600;
  border-bottom: 1px solid var(--ink);
}

/* ==========================================================
   SINGLE POST
   ========================================================== */

.post-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--rule);
}

.post-meta {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--ink-faded);
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

.post-title {
  margin-block: 0 0.5rem;
  max-width: 22ch;
}

.post-lede {
  font-style: italic;
  color: var(--ink-soft);
  font-size: 1.125rem;
  line-height: 1.5;
  max-width: 60ch;
  margin: 1rem 0 0;
}

.post-thumbnail {
  margin: 0 0 2rem;
}

.post-content {
  font-size: 1.0625rem;
  line-height: 1.75;
}

.post-content > * {
  max-width: 64ch;
}

.post-content > .alignwide {
  max-width: 1000px;
}

.post-content > .alignfull {
  max-width: none;
}

.post-content h2 {
  margin-block: 3rem 1rem;
  scroll-margin-top: 6rem;
}

.post-content h3 {
  margin-block: 2rem 0.75rem;
}

.post-footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.875rem;
  color: var(--ink-faded);
}

/* Post navigation (prev/next) */
.post-navigation {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.post-navigation .nav-previous,
.post-navigation .nav-next {
  font-family: var(--sans);
}

.post-navigation .nav-next {
  text-align: right;
}

.post-navigation a {
  text-decoration: none;
  display: block;
}

.post-navigation .nav-subtitle {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faded);
  margin-bottom: 0.5rem;
}

.post-navigation .nav-title {
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.35;
  color: var(--ink);
  letter-spacing: -0.008em;
}

.post-navigation a:hover .nav-title {
  color: var(--accent);
}

/* ==========================================================
   PILLAR (long-form template with TOC)
   ========================================================== */

.pillar-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 3rem;
  max-width: var(--container);
  margin-inline: auto;
}

.pillar-layout .post-content {
  min-width: 0;
}

.pillar-toc {
  position: sticky;
  top: 6rem;
  align-self: start;
  padding: 1.25rem;
  background: var(--paper-deep);
  border: 1px solid var(--rule);
  font-family: var(--sans);
}

.pillar-toc__heading {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faded);
  margin: 0 0 0.75rem;
}

.pillar-toc__nav ol {
  list-style: none;
  padding: 0;
  margin: 0;
  counter-reset: toc;
}

.pillar-toc__nav li {
  counter-increment: toc;
  margin-block: 0.5rem;
  padding-left: 2rem;
  position: relative;
  line-height: 1.4;
}

.pillar-toc__nav li::before {
  content: counter(toc, decimal-leading-zero);
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--ink-faded);
  position: absolute;
  left: 0;
  top: 0.15rem;
}

.pillar-toc__nav a {
  font-size: 0.875rem;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}

.pillar-toc__nav a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* ==========================================================
   SEARCH FORM
   ========================================================== */

.search-form {
  display: flex;
  max-width: 28rem;
  border: 1px solid var(--rule-strong);
  background: var(--paper);
  margin-block: 1.5rem 0;
}

.search-form:focus-within {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}

.search-form input[type="search"] {
  flex: 1;
  border: none;
  padding: 0.6rem 0.875rem;
  background: transparent;
  font-family: var(--sans);
  font-size: 0.95rem;
  color: var(--ink);
}

.search-form input[type="search"]:focus {
  outline: none;
}

.search-form input[type="search"]::placeholder {
  color: var(--ink-faded);
}

.search-form button {
  background: var(--ink);
  color: var(--paper);
  border: none;
  padding: 0.6rem 1.25rem;
  font-family: var(--sans);
  font-size: 0.875rem;
  cursor: pointer;
  letter-spacing: 0.02em;
}

.search-form button:hover {
  background: var(--accent);
}

/* ==========================================================
   404
   ========================================================== */

.error-404 {
  text-align: left;
  padding-block: 4rem;
}

.error-404 .page-title {
  font-size: clamp(2rem, 4vw, 2.625rem);
  max-width: 28ch;
}

.error-404 p {
  font-size: 1.125rem;
  color: var(--ink-soft);
  max-width: 56ch;
}

/* ==========================================================
   FOOTER
   ========================================================== */

.site-footer {
  margin-top: 4rem;
  padding-block: 2.5rem 1.5rem;
  background: var(--paper-deep);
  border-top: 1px solid var(--rule);
}

.site-footer__top {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-start;
  gap: 2rem;
  margin-bottom: 2rem;
}

.site-footer__brand .site-title {
  font-size: 1.25rem;
}

.site-footer__brand p {
  font-family: var(--serif);
  font-size: 0.95rem;
  color: var(--ink-soft);
  max-width: 42ch;
  margin: 0.5rem 0 0;
}

.footer-nav {
  font-family: var(--sans);
  font-size: 0.92rem;
}

.footer-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
}

.footer-nav a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}

.footer-nav a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.site-footer__base {
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-faded);
  letter-spacing: 0.04em;
}

/* ==========================================================
   COMMENTS (suppressed by default in functions.php; minimal styles for if enabled)
   ========================================================== */

.comments-area {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.95rem;
}

/* ==========================================================
   FORMS (default)
   ========================================================== */

input[type="text"],
input[type="email"],
input[type="url"],
input[type="search"],
textarea,
select {
  font-family: var(--sans);
  font-size: 0.95rem;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--rule-strong);
  background: var(--paper);
  color: var(--ink);
}

button,
.button,
input[type="submit"] {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.875rem;
  padding: 0.65rem 1.5rem;
  background: var(--ink);
  color: var(--paper);
  border: none;
  cursor: pointer;
  letter-spacing: 0.02em;
}

button:hover,
.button:hover,
input[type="submit"]:hover {
  background: var(--accent);
}

/* ==========================================================
   GUTENBERG BLOCK SUPPORT
   ========================================================== */

.alignleft {
  float: left;
  margin-right: 1.5rem;
  margin-bottom: 1rem;
}
.alignright {
  float: right;
  margin-left: 1.5rem;
  margin-bottom: 1rem;
}
.aligncenter {
  display: block;
  margin-inline: auto;
}

.wp-caption {
  margin-bottom: 1.5rem;
  max-width: 100%;
}
.wp-caption-text {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--ink-faded);
  text-align: center;
  margin-top: 0.5rem;
}

.wp-block-quote {
  margin: 2rem 0;
  padding-left: 1.25rem;
  border-left: 3px solid var(--rule-strong);
  font-style: italic;
  color: var(--ink-soft);
}

.wp-block-pullquote {
  border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  padding: 1.5rem 0;
  margin: 3rem 0;
  text-align: center;
}

.wp-block-button__link {
  background: var(--ink);
  color: var(--paper);
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.875rem;
  padding: 0.65rem 1.5rem;
  text-decoration: none;
  display: inline-block;
  border-radius: 0;
}

.wp-block-button__link:hover {
  background: var(--accent);
  color: var(--paper);
}

.wp-block-separator {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 2.5rem auto;
  max-width: 240px;
}

.wp-block-cover {
  margin-block: 2rem;
}

.wp-block-image figcaption {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--ink-faded);
  text-align: center;
}

/* ==========================================================
   RESPONSIVE
   ========================================================== */

/* Tablet 768-1279 */
@media (max-width: 1279px) {
  .article-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 2rem;
  }
  .pillar-layout {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .pillar-toc {
    position: static;
  }
}

/* Mobile ≤767 */
@media (max-width: 767px) {
  html { font-size: 16px; }
  .container { padding-inline: 1rem; }

  .site-header__inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
    padding-block: 1rem;
  }

  .menu-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
  }

  .primary-nav ul {
    flex-direction: column;
    gap: 0.5rem;
    width: 100%;
  }

  .primary-nav {
    display: none;
    width: 100%;
    border-top: 1px solid var(--rule);
    margin-top: 0.5rem;
    padding-top: 1rem;
  }

  .primary-nav.is-open {
    display: block;
  }

  .primary-nav .sub-menu {
    position: static;
    border: none;
    background: transparent;
    padding: 0.25rem 0 0.25rem 1rem;
    margin: 0;
  }

  .article-list {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .article-card--featured {
    grid-template-columns: 1fr;
    gap: 1rem;
    padding-bottom: 2rem;
  }

  .post-navigation {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .post-navigation .nav-next {
    text-align: left;
  }

  .site-footer__top {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-footer__base {
    flex-direction: column;
    gap: 0.5rem;
  }
}

/* Print */
@media print {
  .site-header,
  .site-footer,
  .pillar-toc,
  .post-navigation,
  .pagination,
  .search-form,
  .skip-link {
    display: none !important;
  }
  body { background: white; color: black; font-size: 11pt; line-height: 1.5; }
  .post-content > * { max-width: none; }
}