/* Site-specific styles layered on top of anthropic.css
 * Keep additions small — prefer anth-* classes for all visual grammar.
 */

/* Smooth anchor scrolling + room under sticky nav so hashes land visibly */
html {
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

/* Language picker buttons on landing */
.lang-picker {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  margin-top: var(--space-7);
}

.lang-picker .anth-button {
  min-width: 200px;
  text-align: center;
  padding: 16px 32px;
  font-size: 16px;
}

/* Topic cards: taller, consistent heights, 3-col desktop */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-5);
  margin-top: var(--space-7);
}

@media (max-width: 1024px) {
  .topic-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .topic-grid {
    grid-template-columns: 1fr;
  }
}

.topic-card {
  background: #ffffff;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: var(--space-6);
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  transition: transform var(--duration-sm) var(--ease-anth),
    box-shadow var(--duration-sm) var(--ease-anth);
  border: 1px solid transparent;
}

.topic-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-pop);
  border-color: var(--anth-light-gray);
}

.topic-card h3 {
  font-size: 26px;
  font-weight: 600;
}

.topic-card .topic-count {
  font-family: var(--font-heading);
  font-size: 13px;
  color: var(--anth-text-secondary);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.topic-card .topic-desc {
  font-family: var(--font-body);
  color: var(--anth-text-secondary);
  line-height: 1.55;
  margin: 0;
}

/* Article list on category pages */
.paper-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
  margin-top: var(--space-6);
}

.paper-row {
  background: #ffffff;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: var(--space-5) var(--space-6);
  text-decoration: none;
  color: inherit;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: start;
  gap: var(--space-5);
  transition: transform var(--duration-sm) var(--ease-anth),
    box-shadow var(--duration-sm) var(--ease-anth);
}

.paper-row:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-pop);
}

.paper-row .paper-year {
  font-family: var(--font-heading);
  font-size: 28px;
  font-weight: 600;
  color: var(--anth-orange);
  line-height: 1;
  min-width: 70px;
}

.paper-row h3 {
  font-size: 22px;
  font-weight: 600;
  margin: 0 0 var(--space-2);
}

.paper-row .paper-meta {
  font-size: 13px;
  color: var(--anth-text-secondary);
  margin-bottom: var(--space-2);
  font-family: var(--font-heading);
  letter-spacing: 0.02em;
}

.paper-row p {
  margin: 0;
  color: var(--anth-text-secondary);
  font-size: 16px;
  line-height: 1.55;
}

.paper-row .paper-arrow {
  color: var(--anth-orange);
  font-family: var(--font-heading);
  font-size: 20px;
  align-self: center;
}

@media (max-width: 640px) {
  .paper-row {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }
  .paper-row .paper-arrow {
    display: none;
  }
}

/* Language toggle (top-right of non-landing pages) */
.lang-toggle {
  display: inline-flex;
  gap: var(--space-2);
  background: var(--anth-bg-subtle);
  border-radius: var(--radius-pill);
  padding: 4px;
  font-family: var(--font-heading);
  font-size: 13px;
  font-weight: 500;
}

.lang-toggle a {
  text-decoration: none;
  color: var(--anth-text-secondary);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  transition: all var(--duration-sm) var(--ease-anth);
}

.lang-toggle a.active {
  background: var(--anth-text);
  color: var(--anth-bg);
}

.lang-toggle a:hover:not(.active) {
  color: var(--anth-text);
}

/* Article page: long-form reading */
.article-body {
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.75;
}

.article-body h1 {
  font-size: 44px;
  line-height: 1.15;
  margin-bottom: var(--space-5);
}

.article-body h2 {
  font-size: 30px;
  line-height: 1.25;
  margin-top: var(--space-8);
  margin-bottom: var(--space-4);
  font-weight: 600;
}

.article-body h3 {
  font-size: 22px;
  line-height: 1.35;
  margin-top: var(--space-6);
  margin-bottom: var(--space-3);
  font-weight: 600;
}

.article-body h4 {
  font-size: 18px;
  line-height: 1.4;
  margin-top: var(--space-5);
  margin-bottom: var(--space-2);
  font-weight: 600;
  font-family: var(--font-heading);
}

.article-body p {
  margin: 0 0 var(--space-4);
}

.article-body ul,
.article-body ol {
  margin: 0 0 var(--space-5);
  padding-left: var(--space-5);
}

.article-body li {
  margin-bottom: var(--space-2);
}

.article-body blockquote {
  border-left: 3px solid var(--anth-orange);
  margin: var(--space-5) 0;
  padding: var(--space-2) var(--space-5);
  color: var(--anth-text-secondary);
  font-style: italic;
  background: var(--anth-bg-subtle);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.article-body blockquote p:last-child {
  margin-bottom: 0;
}

.article-body code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--anth-bg-subtle);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  color: var(--anth-text);
}

.article-body pre {
  background: #1f1e1a;
  color: #f5f2e8;
  padding: var(--space-5);
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.55;
  margin: var(--space-5) 0;
}

.article-body pre code {
  background: transparent;
  color: inherit;
  padding: 0;
  font-size: inherit;
}

.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-5) 0;
  font-size: 15px;
  font-family: var(--font-body);
}

.article-body th,
.article-body td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border-bottom: 1px solid var(--anth-light-gray);
  vertical-align: top;
}

.article-body th {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 13px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--anth-text-secondary);
  background: var(--anth-bg-subtle);
}

.article-body tr:last-child td {
  border-bottom: 0;
}

.article-body a {
  color: var(--anth-orange);
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

.article-body a:hover {
  color: var(--anth-orange-hover);
}

.article-body hr {
  border: 0;
  border-top: 1px solid var(--anth-light-gray);
  margin: var(--space-7) 0;
}

.article-body img,
.article-body svg {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
}

/* Article top meta block */
.article-meta-header {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
  margin-bottom: var(--space-5);
}

/* Prev/Next nav at article bottom */
.article-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-5);
  margin-top: var(--space-9);
  padding-top: var(--space-6);
  border-top: 1px solid var(--anth-light-gray);
}

.article-nav a {
  text-decoration: none;
  color: inherit;
  padding: var(--space-4) var(--space-5);
  background: var(--anth-bg-subtle);
  border-radius: var(--radius-md);
  transition: background var(--duration-sm) var(--ease-anth);
}

.article-nav a:hover {
  background: var(--anth-light-gray);
}

.article-nav .nav-label {
  font-family: var(--font-heading);
  font-size: 12px;
  color: var(--anth-text-secondary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.article-nav .nav-title {
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 500;
  margin-top: var(--space-2);
}

.article-nav .nav-right {
  text-align: right;
}

@media (max-width: 640px) {
  .article-nav {
    grid-template-columns: 1fr;
  }
}

/* Stat counters on landing */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-5);
  margin-top: var(--space-7);
}

@media (max-width: 768px) {
  .stat-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.stat {
  text-align: center;
  padding: var(--space-5);
  background: #ffffff;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
}

.stat-number {
  font-family: var(--font-heading);
  font-size: 56px;
  font-weight: 700;
  color: var(--anth-orange);
  line-height: 1;
  margin-bottom: var(--space-2);
}

.stat-label {
  font-family: var(--font-heading);
  font-size: 13px;
  color: var(--anth-text-secondary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* Diagram container */
.diagram-frame {
  background: #ffffff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: var(--space-6);
  margin: var(--space-7) 0;
}

.diagram-frame svg {
  display: block;
  width: 100%;
  height: auto;
}

.diagram-caption {
  text-align: center;
  font-size: 13px;
  color: var(--anth-text-secondary);
  margin-top: var(--space-4);
  font-family: var(--font-heading);
}

/* Site-branded badge palette extensions */
.anth-badge.badge-inference {
  background: var(--anth-blue);
  color: #ffffff;
}
.anth-badge.badge-self {
  background: var(--anth-orange);
  color: #ffffff;
}
.anth-badge.badge-multi,
.anth-badge.badge-agent {
  background: var(--anth-green);
  color: #ffffff;
}
.anth-badge.badge-memory {
  background: var(--anth-text);
  color: var(--anth-bg);
}
.anth-badge.badge-models {
  background: var(--anth-mid-gray);
  color: var(--anth-text);
}
.anth-badge.badge-training {
  background: var(--anth-danger);
  color: #ffffff;
}
.anth-badge.badge-thinking {
  background: #6b8e3c;
  color: #ffffff;
}

/* Footer tighter */
.site-footer-brand {
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

/* Top nav brand */
.site-brand {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 18px;
  letter-spacing: -0.01em;
  color: var(--anth-text);
  text-decoration: none;
}

/* Topics dropdown menu */
.nav-dropdown {
  position: relative;
  display: inline-block;
}

.nav-dropdown > button {
  background: transparent;
  border: 0;
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 500;
  color: var(--anth-text);
  cursor: pointer;
  padding: 8px 0;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.nav-dropdown > button::after {
  content: "▾";
  font-size: 10px;
  margin-top: 1px;
  color: var(--anth-text-secondary);
}

.nav-dropdown-panel {
  position: absolute;
  top: 100%;
  left: 0;
  background: #ffffff;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-pop);
  padding: var(--space-3);
  min-width: 320px;
  z-index: 100;
  border: 1px solid var(--anth-light-gray);
  /* show/hide with opacity so we can transition + add a small close delay
   * (rather than display:none which can't transition). */
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-4px);
  transition: opacity 160ms var(--ease-anth),
              transform 160ms var(--ease-anth),
              visibility 160ms;
  transition-delay: 150ms; /* small close delay — mouse can reach the panel */
}

/* Transparent bridge that fills the 8px visual gap between button and panel,
 * so the mouse path "button → panel" stays inside .nav-dropdown's hover area. */
.nav-dropdown-panel::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 0;
  right: 0;
  height: 8px;
}

.nav-dropdown:hover .nav-dropdown-panel,
.nav-dropdown:focus-within .nav-dropdown-panel {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(6px); /* the 6px visible drop below the button */
  transition-delay: 0ms;      /* open instantly */
}

.nav-dropdown-panel a {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: inherit;
  transition: background var(--duration-sm) var(--ease-anth);
}

.nav-dropdown-panel a:hover {
  background: var(--anth-bg-subtle);
}

.nav-dropdown-panel .dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.nav-dropdown-panel .label {
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 500;
  color: var(--anth-text);
}

.nav-dropdown-panel .sub {
  font-family: var(--font-body);
  font-size: 12px;
  color: var(--anth-text-secondary);
}

/* AI engineering stack diagram container */
.stack-diagram {
  background: #ffffff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: var(--space-7);
  margin: var(--space-8) auto;
}

.stack-diagram svg {
  display: block;
  width: 100%;
  height: auto;
  max-width: 1080px;
  margin: 0 auto;
}

.stack-caption {
  text-align: center;
  font-family: var(--font-heading);
  font-size: 13px;
  color: var(--anth-text-secondary);
  margin-top: var(--space-5);
  letter-spacing: 0.02em;
}