/* ============================================================
   ChessSRS Documentation Theme & Layout
   Inherits design tokens and fonts from ../styles.css
   ============================================================ */

.doc-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.doc-wrap {
  width: min(100% - 2 * var(--g), 1400px);
  margin-inline: auto;
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr) 220px;
  gap: 40px;
  padding: 40px 0 80px;
  flex: 1;
}

@media (max-width: 1160px) {
  .doc-wrap {
    grid-template-columns: 240px minmax(0, 1fr);
  }
  .doc-toc-aside {
    display: none;
  }
}

@media (max-width: 820px) {
  .doc-wrap {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 20px 0 60px;
  }
  .doc-sidebar {
    position: static;
    max-height: none;
    border-bottom: 1px solid var(--ln);
    padding-bottom: 24px;
    margin-bottom: 16px;
  }
}

/* Sidebar navigation */
.doc-sidebar {
  position: sticky;
  top: 96px;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
  padding-right: 16px;
  scrollbar-width: thin;
}

.doc-sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.doc-nav-group-title {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--mu);
  margin-bottom: 8px;
}

.doc-nav-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.doc-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 7px 12px;
  border-radius: 6px;
  font-size: 14.5px;
  color: var(--tx);
  text-decoration: none;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.doc-nav-link:hover {
  background-color: var(--bg2);
  color: var(--ac);
}

.doc-nav-link.active {
  background-color: var(--sf);
  color: var(--ac);
  font-weight: 600;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  border: 1px solid var(--ln);
}

.doc-nav-badge {
  font-family: var(--mono);
  font-size: 10.5px;
  padding: 1px 6px;
  border-radius: 99px;
  background: var(--bg2);
  color: var(--mu);
}

.doc-nav-link.active .doc-nav-badge {
  background: var(--ac);
  color: #fff;
}

/* Article content */
.doc-article {
  max-width: 820px;
  line-height: 1.7;
}

.doc-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--mu);
  margin-bottom: 16px;
}

.doc-breadcrumb a {
  color: var(--mu);
  text-decoration: none;
}

.doc-breadcrumb a:hover {
  color: var(--tx);
  text-decoration: underline;
}

.doc-kicker {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ac);
  margin-bottom: 8px;
  display: block;
}

.doc-title {
  font-family: var(--serif);
  font-size: clamp(34px, 4.5vw, 52px);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--tx);
  margin-bottom: 16px;
}

.doc-lede {
  font-size: 19px;
  line-height: 1.55;
  color: var(--mu);
  margin-bottom: 24px;
}

.doc-meta-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background-color: var(--sf);
  border: 1px solid var(--ln);
  border-radius: 8px;
  margin-bottom: 36px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--mu);
}

.doc-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.doc-meta-item a {
  color: var(--ac);
  text-decoration: none;
  font-weight: 500;
}

.doc-meta-item a:hover {
  text-decoration: underline;
}

/* Headings in content */
.doc-article h2 {
  font-family: var(--serif);
  font-size: clamp(26px, 3vw, 34px);
  font-weight: 400;
  line-height: 1.2;
  color: var(--tx);
  margin-top: 48px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--ln);
  scroll-margin-top: 100px;
}

.doc-article h3 {
  font-family: var(--sans);
  font-size: 20px;
  font-weight: 600;
  color: var(--tx);
  margin-top: 32px;
  margin-bottom: 12px;
  scroll-margin-top: 100px;
}

.doc-article h4 {
  font-family: var(--sans);
  font-size: 16px;
  font-weight: 600;
  color: var(--tx);
  margin-top: 24px;
  margin-bottom: 8px;
}

.doc-article p {
  margin-bottom: 18px;
}

.doc-article ul, .doc-article ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

.doc-article li {
  margin-bottom: 8px;
}

.doc-article ul {
  list-style: disc;
}

.doc-article ol {
  list-style: decimal;
}

/* Callouts */
.callout {
  padding: 18px 22px;
  border-radius: 8px;
  margin: 24px 0;
  background-color: var(--sf);
  border-left: 4px solid var(--ac);
  border-top: 1px solid var(--ln);
  border-right: 1px solid var(--ln);
  border-bottom: 1px solid var(--ln);
}

.callout-title {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.callout.note {
  border-left-color: #1d4ed8;
}
.callout.note .callout-title {
  color: #1d4ed8;
}
:root[data-theme="dark"] .callout.note {
  border-left-color: #60a5fa;
}
:root[data-theme="dark"] .callout.note .callout-title {
  color: #60a5fa;
}

.callout.spec {
  border-left-color: var(--ac);
}
.callout.spec .callout-title {
  color: var(--ac);
}

.callout.math {
  border-left-color: #8b5cf6;
}
.callout.math .callout-title {
  color: #8b5cf6;
}

.callout.warning {
  border-left-color: #b91c1c;
}
.callout.warning .callout-title {
  color: #b91c1c;
}
:root[data-theme="dark"] .callout.warning {
  border-left-color: #f87171;
}
:root[data-theme="dark"] .callout.warning .callout-title {
  color: #f87171;
}

.callout p:last-child {
  margin-bottom: 0;
}

/* Math formula cards */
.math-card {
  background-color: var(--sf);
  border: 1px solid var(--ln);
  border-radius: 10px;
  padding: 24px;
  margin: 24px 0;
}

.math-display {
  font-family: var(--mono);
  font-size: 15px;
  line-height: 1.8;
  background-color: var(--bg2);
  padding: 16px 20px;
  border-radius: 6px;
  overflow-x: auto;
  margin: 12px 0 16px;
  color: var(--tx);
  border: 1px solid var(--ln);
}

.math-legend {
  font-size: 14px;
  color: var(--mu);
  line-height: 1.6;
}

.math-legend strong {
  color: var(--tx);
  font-family: var(--mono);
}

/* Code blocks */
.code-block {
  margin: 20px 0;
  border-radius: 8px;
  background-color: var(--bg2);
  border: 1px solid var(--ln);
  overflow: hidden;
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 16px;
  font-family: var(--mono);
  font-size: 11px;
  background-color: var(--sf);
  border-bottom: 1px solid var(--ln);
  color: var(--mu);
}

.code-block pre {
  margin: 0;
  padding: 16px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--tx);
}

code.inline-code {
  font-family: var(--mono);
  font-size: 0.9em;
  padding: 2px 6px;
  border-radius: 4px;
  background-color: var(--bg2);
  border: 1px solid var(--ln);
  color: var(--tx);
}

/* Invariant cards */
.inv-card {
  background-color: var(--sf);
  border: 1px solid var(--ln);
  border-radius: 8px;
  padding: 20px;
  margin: 20px 0;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.inv-card:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.inv-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.inv-id {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--ac);
}

.inv-badge {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 99px;
  text-transform: uppercase;
}

.inv-badge.t0 {
  background-color: #fee2e2;
  color: #991b1b;
}
:root[data-theme="dark"] .inv-badge.t0 {
  background-color: #450a0a;
  color: #fca5a5;
}

.inv-badge.t1 {
  background-color: #fef3c7;
  color: #92400e;
}
:root[data-theme="dark"] .inv-badge.t1 {
  background-color: #451a03;
  color: #fcd34d;
}

.inv-badge.t2 {
  background-color: #e0f2fe;
  color: #075985;
}
:root[data-theme="dark"] .inv-badge.t2 {
  background-color: #082f49;
  color: #7dd3fc;
}

.inv-statement {
  font-size: 16px;
  font-weight: 500;
  color: var(--tx);
  margin-bottom: 12px;
  line-height: 1.5;
}

.inv-meta {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--mu);
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-top: 1px dashed var(--ln);
  padding-top: 10px;
}

/* Tables */
.doc-table-wrap {
  width: 100%;
  overflow-x: auto;
  margin: 24px 0;
  border: 1px solid var(--ln);
  border-radius: 8px;
  background-color: var(--sf);
}

.doc-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14.5px;
  text-align: left;
}

.doc-table th {
  background-color: var(--bg2);
  padding: 12px 16px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--tx);
  border-bottom: 1px solid var(--ln);
}

.doc-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--ln);
  vertical-align: top;
}

.doc-table tr:last-child td {
  border-bottom: none;
}

.doc-table tr:hover td {
  background-color: var(--bg2);
}

/* On-this-page Table of Contents */
.doc-toc-aside {
  position: sticky;
  top: 96px;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
}

.doc-toc-title {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--mu);
  margin-bottom: 12px;
}

.doc-toc-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-left: 1px solid var(--ln);
  padding-left: 14px;
}

.doc-toc-item a {
  font-size: 13.5px;
  color: var(--mu);
  text-decoration: none;
  line-height: 1.4;
  display: block;
  transition: color 0.15s ease;
}

.doc-toc-item a:hover {
  color: var(--ac);
}

/* Pagination buttons at bottom of article */
.doc-pagination {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 60px;
  padding-top: 32px;
  border-top: 1px solid var(--ln);
}

@media (max-width: 600px) {
  .doc-pagination {
    grid-template-columns: 1fr;
  }
}

.doc-page-card {
  display: flex;
  flex-direction: column;
  padding: 16px 20px;
  border-radius: 8px;
  background-color: var(--sf);
  border: 1px solid var(--ln);
  text-decoration: none;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.doc-page-card:hover {
  border-color: var(--ac);
  transform: translateY(-2px);
}

.doc-page-card.prev {
  text-align: left;
}

.doc-page-card.next {
  text-align: right;
  grid-column: 2;
}

@media (max-width: 600px) {
  .doc-page-card.next {
    grid-column: auto;
  }
}

.doc-page-dir {
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--mu);
  margin-bottom: 4px;
}

.doc-page-label {
  font-family: var(--sans);
  font-size: 16px;
  font-weight: 600;
  color: var(--tx);
}

/* Hub Category Cards on docs/index.html */
.doc-hub-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
  margin: 32px 0 48px;
}

.doc-hub-card {
  background-color: var(--sf);
  border: 1px solid var(--ln);
  border-radius: 10px;
  padding: 24px;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}

.doc-hub-card:hover {
  transform: translateY(-2px);
  border-color: var(--ac);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.04);
}

.doc-hub-card-kicker {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ac);
  margin-bottom: 8px;
}

.doc-hub-card-title {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 400;
  line-height: 1.2;
  color: var(--tx);
  margin-bottom: 8px;
}

.doc-hub-card-desc {
  font-size: 14.5px;
  color: var(--mu);
  line-height: 1.55;
  margin-bottom: 16px;
}

.doc-hub-card-footer {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ac);
  display: flex;
  align-items: center;
  gap: 4px;
  font-weight: 500;
}