/* ================================================
   Reader Typography & Layout
   Used by /blog/:slug and /papers/:slug
   ================================================ */

@font-face {
  font-family: 'Source Serif 4';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('/assets/fonts/source-serif-4-regular.woff2') format('woff2');
}

@font-face {
  font-family: 'Source Serif 4';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url('/assets/fonts/source-serif-4-italic.woff2') format('woff2');
}

@font-face {
  font-family: 'Source Serif 4';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url('/assets/fonts/source-serif-4-semibold.woff2') format('woff2');
}

:root {
  --font-serif: 'Source Serif 4', 'Iowan Old Style', 'Charter', Georgia, serif;
  --reader-fg: #1f1d1a;
  --reader-fg-muted: #5c5c58;
  --reader-fg-subtle: #8a8a85;
  --reader-bg: #fdfcfa;
  --reader-rule: #e6e0d2;
  --reader-accent: #C86D5C;
  --reader-link: #1d4ed8;
  --reader-callout-bg: #f6f1e7;
  --reader-code-bg: #fbf7ee;
}

.reader-body {
  background: var(--reader-bg);
  color: var(--reader-fg);
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

/* aria-current on the active site nav link */
.reader-body .nav-link[aria-current="page"] {
  color: var(--terracotta, #C86D5C);
}

/* ---------- Layout ---------- */
.reader-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 6rem;
}

@media (min-width: 1024px) {
  .reader-layout.has-toc {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 3rem;
    padding-top: 3.5rem;
  }
}

.reader-main {
  min-width: 0;
}

/* ---------- TOC ---------- */
.reader-toc {
  display: none;
}

@media (min-width: 1024px) {
  .reader-toc {
    display: block;
    align-self: start;
    position: sticky;
    top: 5rem;
    max-height: calc(100vh - 6rem);
    overflow-y: auto;
  }
}

.reader-toc-inner {
  border-left: 2px solid var(--reader-rule);
  padding: 0.25rem 0 0.25rem 1rem;
}

.reader-toc-heading {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--reader-fg-subtle);
  margin: 0 0 0.85rem 0;
}

.reader-toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.toc-item a {
  display: block;
  font-size: 0.875rem;
  line-height: 1.4;
  color: var(--reader-fg-muted);
  text-decoration: none;
  transition: color 150ms ease;
}

.toc-item a:hover {
  color: var(--reader-accent);
}

.toc-item.is-active > a {
  color: var(--reader-fg);
  font-weight: 600;
}

.toc-l3 { padding-left: 0.85rem; }
.toc-l4 { padding-left: 1.7rem; }

/* ---------- Article wrapper ---------- */
.reader {
  max-width: 70ch;
  margin: 0 auto;
}

.reader-header {
  margin-bottom: 2.5rem;
}

.reader-back {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--reader-fg-muted);
  text-decoration: none;
  margin-bottom: 1.5rem;
  transition: color 150ms ease;
}

.reader-back:hover {
  color: var(--reader-accent);
}

.reader-eyebrow {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--reader-accent);
  margin: 0 0 0.85rem 0;
}

.reader-title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.15;
  letter-spacing: -0.015em;
  color: var(--reader-fg);
  margin: 0 0 0.75rem 0;
}

.reader-subtitle {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(1.125rem, 1.6vw, 1.4rem);
  line-height: 1.4;
  color: var(--reader-fg-muted);
  margin: 0 0 1.25rem 0;
}

.reader-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--reader-fg-subtle);
}

.reader-meta-sep {
  color: var(--reader-fg-subtle);
  opacity: 0.6;
}

.reader-hero-image {
  display: block;
  width: 100%;
  height: auto;
  margin-top: 2rem;
  border-radius: 0.75rem;
}

/* ---------- Abstract (papers) ---------- */
.reader-abstract {
  margin: 2.5rem 0;
  padding: 1.5rem 1.75rem;
  background: var(--reader-callout-bg);
  border-left: 3px solid var(--reader-accent);
  border-radius: 0 0.5rem 0.5rem 0;
}

.reader-abstract h2 {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--reader-fg-muted);
  margin: 0 0 0.75rem 0;
}

.reader-abstract p {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.65;
  color: var(--reader-fg);
  margin: 0;
}

/* ---------- Article body ---------- */
.reader-content {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  line-height: 1.7;
  color: var(--reader-fg);
  hanging-punctuation: first last;
}

.reader-content > * + * {
  margin-top: 1.25rem;
}

.reader-content p {
  margin: 0;
}

.reader-content h2,
.reader-content h3,
.reader-content h4 {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--reader-fg);
  scroll-margin-top: 5rem;
}

.reader-content h2 {
  font-size: 1.625rem;
  line-height: 1.25;
  margin-top: 3rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--reader-rule);
}

.reader-content h3 {
  font-size: 1.275rem;
  line-height: 1.3;
  margin-top: 2.25rem;
}

.reader-content h4 {
  font-size: 1.1rem;
  margin-top: 1.75rem;
}

.reader-content a {
  color: var(--reader-link);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 150ms ease;
}

.reader-content a:hover {
  color: var(--reader-accent);
}

.reader-content strong { font-weight: 600; }
.reader-content em { font-style: italic; }

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

.reader-content li {
  margin-bottom: 0.4rem;
}

.reader-content li > p {
  margin-bottom: 0.4rem;
}

.reader-content blockquote {
  margin: 1.5rem 0;
  padding: 0.25rem 0 0.25rem 1.25rem;
  border-left: 3px solid var(--reader-rule);
  color: var(--reader-fg-muted);
  font-style: italic;
}

.reader-content img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1.5rem auto;
  border-radius: 0.5rem;
}

.reader-content hr {
  border: 0;
  border-top: 1px solid var(--reader-rule);
  margin: 2rem 0;
}

.reader-content table {
  width: 100%;
  border-collapse: collapse;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 0.95rem;
  margin: 1.25rem 0;
}

.reader-content th,
.reader-content td {
  text-align: left;
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--reader-rule);
}

.reader-content th {
  font-weight: 600;
  color: var(--reader-fg);
  border-bottom: 2px solid var(--reader-fg);
}

/* ---------- Inline code & code blocks ---------- */
.reader-content code {
  font-family: ui-monospace, 'SF Mono', SFMono-Regular, Menlo, Monaco, 'Cascadia Mono', Consolas, monospace;
  font-size: 0.92em;
  background: var(--reader-code-bg);
  padding: 0.1em 0.35em;
  border-radius: 0.25em;
  color: var(--reader-fg);
  border: 1px solid var(--reader-rule);
}

.reader-content pre {
  margin: 1.25rem 0;
  position: relative;
}

.reader-content pre.shiki {
  padding: 1rem 1.1rem;
  border-radius: 0.5rem;
  font-size: 0.875rem;
  line-height: 1.55;
  overflow-x: auto;
  border: 1px solid var(--reader-rule);
  background-color: #fbf7ee !important;
}

.reader-content pre.shiki code {
  background: transparent;
  border: 0;
  padding: 0;
  font-size: inherit;
  color: inherit;
  display: block;
}

.reader-content pre.shiki .line {
  display: inline-block;
  width: 100%;
  min-height: 1.1em;
}

.reader-copy-button {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  padding: 0.3rem 0.55rem;
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--reader-rule);
  border-radius: 0.35rem;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--reader-fg-muted);
  cursor: pointer;
  opacity: 0;
  transition: opacity 150ms ease, color 150ms ease;
}

.reader-content pre:hover .reader-copy-button,
.reader-copy-button:focus-visible {
  opacity: 1;
}

.reader-copy-button:hover {
  color: var(--reader-fg);
}

.reader-copy-button.is-copied {
  color: #2f855a;
  opacity: 1;
}

.reader-lang-label {
  position: absolute;
  top: 0.5rem;
  left: 0.85rem;
  font-family: ui-monospace, 'SF Mono', monospace;
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--reader-fg-subtle);
  pointer-events: none;
  opacity: 0.7;
}

/* ---------- Footnotes ---------- */
.reader-content sup.footnote-ref {
  font-size: 0.7em;
  margin-left: 0.1em;
}

.reader-content sup.footnote-ref a {
  text-decoration: none;
  background: var(--reader-callout-bg);
  padding: 0.1em 0.3em;
  border-radius: 0.25em;
  border: 1px solid var(--reader-rule);
  color: var(--reader-link);
}

.reader-content sup.footnote-ref a:hover,
.reader-content sup.footnote-ref a:focus {
  background: var(--reader-accent);
  border-color: var(--reader-accent);
  color: #fff;
}

.reader-content .footnotes {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--reader-rule);
  font-size: 0.95rem;
  color: var(--reader-fg-muted);
}

.reader-content .footnotes hr { display: none; }

.reader-content .footnotes ol {
  padding-left: 1.5rem;
}

.reader-content .footnotes li { margin-bottom: 0.6rem; }

.reader-content .footnotes p { display: inline; margin: 0; }

.reader-content .footnote-backref {
  text-decoration: none;
  margin-left: 0.3em;
}

/* ---------- Footnote popover ---------- */
.reader-footnote-popover {
  position: absolute;
  z-index: 100;
  max-width: 22rem;
  padding: 0.85rem 1rem;
  background: var(--reader-fg);
  color: #fdfcfa;
  border-radius: 0.5rem;
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.875rem;
  line-height: 1.45;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
  pointer-events: none;
}

.reader-footnote-popover a { color: #fdfcfa; text-decoration: underline; }

/* ---------- Tags ---------- */
.reader-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--reader-rule);
}

.reader-tag {
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.8rem;
  padding: 0.3rem 0.75rem;
  background: #f4efe7;
  color: var(--reader-fg-muted);
  border-radius: 9999px;
  border: 1px solid var(--reader-rule);
}

.reader-footer {
  margin-top: 3rem;
}

@media (max-width: 640px) {
  .reader-layout {
    padding: 1.5rem 1rem 4rem;
  }
  .reader-content { font-size: 1.075rem; }
  .reader-title { font-size: clamp(1.7rem, 7vw, 2.25rem); }
  .reader-topbar { padding: 0.7rem 1rem; }
  .reader-topbar-nav { gap: 1rem; }
}