/* ------------------------------------------------------------------
 * Reader-facing typography and layout.
 * Loads AFTER tufte.css + tokens.css, so we override with intent.
 * ------------------------------------------------------------------ */

/* Force light regardless of OS preference. The design is committed. */
html {
  font-size: 100%;
  color-scheme: light;
}

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--type-base);
  line-height: var(--lh-body);
  font-feature-settings: "kern", "liga", "onum", "calt";
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  /* Undo Tufte CSS body width hacks — our grid handles layout */
  width: 100%;
  max-width: none;
  margin: 0;
  padding: 0;
  counter-reset: sidenote-counter;
}

@media (prefers-color-scheme: dark) {
  body {
    background: var(--paper);
    color: var(--ink);
  }
}

/* ------------------------------------------------------------------
 * Three-column grid — left rail, reading column, right rail for margin notes
 * ------------------------------------------------------------------ */

.tufte-container {
  display: grid;
  grid-template-columns:
    [full-start] var(--rail-left)
    [main-start] minmax(0, var(--measure))
    [main-end] var(--rail-right)
    [full-end];
  column-gap: var(--space-lg);
  margin: 0 auto;
  max-width: 82rem;
  padding: var(--space-xl) var(--space-md) var(--space-3xl);
}

.tufte-container > article,
.tufte-container > header,
.tufte-container > section {
  grid-column: main;
  min-width: 0;
}

.tufte-container > aside.left-column {
  grid-column: full-start / main-start;
  align-self: start;
  padding-top: var(--space-xl);
  color: var(--ink-faint);
  font-family: var(--font-ui);
  font-size: var(--type-sm);
}

@media (max-width: 900px) {
  .tufte-container {
    grid-template-columns: minmax(0, 1fr);
    padding: var(--space-lg) var(--space-md) var(--space-2xl);
  }
  .tufte-container > aside.left-column {
    grid-column: 1;
    padding-top: 0;
  }
}

/* ------------------------------------------------------------------
 * Running head — book-like strip at top of every post
 * ------------------------------------------------------------------ */

.running-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-md);
  padding-bottom: var(--space-sm);
  margin-bottom: var(--space-2xl);
  border-bottom: 1px solid var(--paper-rule);
  font-family: var(--font-sc);
  font-size: var(--type-sm);
  letter-spacing: 0.08em;
  text-transform: lowercase;
  color: var(--ink-faint);
}

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

.running-head a:hover {
  color: var(--accent);
}

.running-head .rh-section {
  font-style: italic;
}

/* ------------------------------------------------------------------
 * Headings
 * ------------------------------------------------------------------ */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--ink);
  text-wrap: balance;
  hyphens: manual;
}

h1 {
  font-size: var(--type-display);
  line-height: var(--lh-tight);
  font-weight: 400;
  margin: var(--space-lg) 0 var(--space-md);
  letter-spacing: -0.015em;
}

h2 {
  font-size: var(--type-xxl);
  line-height: var(--lh-tight);
  font-style: italic;
  font-weight: 400;
  margin: var(--space-2xl) 0 var(--space-md);
}

h3 {
  font-size: var(--type-xl);
  line-height: var(--lh-tight);
  font-style: italic;
  font-weight: 400;
  margin: var(--space-xl) 0 var(--space-sm);
}

h4 {
  font-size: var(--type-lg);
  font-weight: 600;
  margin: var(--space-lg) 0 var(--space-xs);
}

.subtitle {
  font-style: italic;
  color: var(--ink-soft);
  font-size: var(--type-lg);
  margin: 0 0 var(--space-xl);
  text-wrap: balance;
}

/* ------------------------------------------------------------------
 * Body copy — the whole point of this blog
 * ------------------------------------------------------------------ */

p, li {
  font-size: var(--type-base);
  line-height: var(--lh-body);
  text-wrap: pretty;
  hyphens: auto;
  word-wrap: break-word;
}

article p,
article li {
  max-width: var(--measure);
}

article p {
  margin: 0 0 var(--space-md);
  text-align: justify;
  text-align-last: left;
  hyphens: auto;
  -webkit-hyphens: auto;
}

article ul, article ol {
  margin: var(--space-md) 0 var(--space-md) var(--space-lg);
  padding: 0;
}

article blockquote {
  margin: var(--space-lg) 0 var(--space-lg) var(--space-md);
  padding-left: var(--space-md);
  border-left: 1px solid var(--paper-rule);
  font-style: italic;
  color: var(--ink-soft);
  max-width: var(--measure);
}

article blockquote p {
  margin-bottom: var(--space-sm);
}

article a {
  color: var(--ink);
  text-decoration-line: underline;
  text-decoration-color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  transition: color var(--dur) var(--ease);
}

article a:hover {
  color: var(--accent);
}

article hr {
  border: 0;
  height: 1px;
  background: var(--paper-rule);
  margin: var(--space-2xl) auto;
  width: 8rem;
}

article strong { font-weight: 600; color: var(--ink); }
article em { font-style: italic; }

/* ------------------------------------------------------------------
 * Drop cap — first paragraph of an article only.
 * Applied by typography.js, scoped here to not leak elsewhere.
 * ------------------------------------------------------------------ */

article > p.drop-cap::first-letter,
article > section > p.drop-cap::first-letter,
p.long-paragraph.drop-cap::first-letter {
  font-family: var(--font-drop);
  font-size: 5em;
  font-weight: normal;
  float: left;
  line-height: 0.82;
  padding: 0.04em 0.08em 0 0;
  color: var(--ink);
}

p.has-goudy-dropcap::first-letter {
  float: none;
  font-size: inherit;
  font-family: inherit;
}

.goudy-dropcap {
  float: left;
  width: 4.4rem;
  height: 4.4rem;
  margin: 0.1rem 0.6rem 0 0;
  shape-outside: margin-box;
}

.goudy-dropcap img {
  width: 100%;
  height: 100%;
  display: block;
}

/* ------------------------------------------------------------------
 * Small caps & figure utilities
 * ------------------------------------------------------------------ */

.sc, abbr {
  font-variant-caps: small-caps;
  font-feature-settings: "smcp", "c2sc";
  letter-spacing: 0.03em;
  text-decoration: none;
}

.onum { font-feature-settings: "onum"; }
.lnum { font-feature-settings: "lnum"; }

/* ------------------------------------------------------------------
 * Sidenotes & marginnotes — desktop: right rail; mobile: inline details
 * ------------------------------------------------------------------ */

.sidenote,
.marginnote {
  float: right;
  clear: right;
  width: calc(var(--rail-right) - var(--space-md));
  margin-right: calc(-1 * var(--rail-right));
  margin-top: 0.2rem;
  margin-bottom: var(--space-md);
  font-size: var(--type-sm);
  line-height: var(--lh-body);
  color: var(--ink-soft);
  vertical-align: baseline;
  position: relative;
}

.sidenote-number {
  counter-increment: sidenote-counter;
}

.sidenote-number::after,
.sidenote::before {
  font-feature-settings: "sups";
  color: var(--accent);
  position: relative;
}

.sidenote-number::after {
  content: counter(sidenote-counter);
  font-size: 0.8rem;
  top: -0.5rem;
  left: 0.1rem;
}

.sidenote::before {
  content: counter(sidenote-counter) " ";
  font-size: 0.72rem;
  top: -0.4rem;
  margin-right: 0.15rem;
}

/* Marginnote inline marker (dagger) */
.marginnote-marker {
  color: var(--accent);
  font-size: 0.85em;
  vertical-align: super;
  cursor: help;
  margin-left: 0.05em;
}

/* Mobile: sidenotes/marginnotes become inline collapsible details */
@media (max-width: 900px) {
  .sidenote,
  .marginnote {
    float: none;
    width: auto;
    margin: var(--space-sm) 0;
    padding: var(--space-sm) var(--space-md);
    background: var(--paper-deep);
    border-radius: 2px;
    display: block;
  }
}

/* ------------------------------------------------------------------
 * Footnotes section — end-of-article list
 * ------------------------------------------------------------------ */

article .footnote {
  font-size: var(--type-sm);
  line-height: var(--lh-body);
  color: var(--ink-soft);
  counter-reset: fn;
  margin-top: var(--space-xl);
  padding-top: var(--space-md);
  border-top: 1px solid var(--paper-rule);
  list-style: none;
  padding-left: 0;
}

article .footnote li {
  counter-increment: fn;
  margin-bottom: var(--space-sm);
  padding-left: var(--space-lg);
  position: relative;
}

article .footnote li::before {
  content: counter(fn);
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--font-sc);
  font-size: 0.78rem;
  color: var(--accent);
  font-feature-settings: "lnum";
}

.footnote-back {
  text-decoration: none;
  margin-left: 0.4em;
  color: var(--ink-faint);
}

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

.footnote-ref {
  vertical-align: super;
  font-size: 0.72em;
  color: var(--accent);
  cursor: pointer;
  margin-left: 0.05em;
  text-decoration: none;
}

/* ------------------------------------------------------------------
 * Code — inline and block
 * ------------------------------------------------------------------ */

code {
  font-family: var(--font-code);
  font-size: 0.88em;
  padding: 0.08em 0.35em;
  background: var(--paper-deep);
  color: var(--ink);
  border-radius: 2px;
  font-feature-settings: "ss01", "ss02";
}

pre {
  background: var(--paper-deep);
  border: 1px solid var(--paper-rule);
  border-radius: 3px;
  padding: var(--space-md);
  overflow-x: auto;
  margin: var(--space-lg) 0;
  max-width: var(--measure-wide);
  font-size: 0.88em;
  line-height: 1.5;
}

pre code {
  background: transparent;
  padding: 0;
  border: 0;
  font-size: inherit;
  color: var(--ink);
  white-space: pre;
}

.mermaid-diagram {
  margin: 2rem 0;
  overflow-x: auto;
  text-align: center;
}

.mermaid-diagram svg {
  height: auto;
  max-width: 100%;
}

.mermaid-error {
  border-color: var(--accent, #8b5a20);
}

/* ------------------------------------------------------------------
 * Math — MathJax integration
 * ------------------------------------------------------------------ */

mjx-container {
  color: var(--ink);
}

mjx-container[display="true"] {
  margin: var(--space-lg) 0 !important;
  max-width: var(--measure);
  overflow-x: auto;
}

/* ------------------------------------------------------------------
 * Cornell notes (left rail)
 * ------------------------------------------------------------------ */

.left-column .cornell-offset-small,
.left-column .cornell-offset-medium,
.left-column .cornell-offset-large {
  position: relative;
  padding: var(--space-sm) var(--space-xs);
  margin-bottom: var(--space-md);
  font-family: var(--font-ui);
  color: var(--ink-soft);
  font-size: var(--type-sm);
  line-height: 1.45;
}

.left-column .cornell-offset-small { top: 2rem; }
.left-column .cornell-offset-medium { top: 6rem; }
.left-column .cornell-offset-large { top: 10rem; }

@media (max-width: 900px) {
  .left-column .cornell-offset-small,
  .left-column .cornell-offset-medium,
  .left-column .cornell-offset-large {
    top: 0;
    margin-bottom: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: var(--paper-deep);
    border-left: 1px solid var(--accent);
  }
}

/* ------------------------------------------------------------------
 * Index / homepage
 * ------------------------------------------------------------------ */

.index-header {
  max-width: var(--measure);
  margin-bottom: var(--space-2xl);
}

.index-title {
  font-family: var(--font-body);
  font-size: var(--type-xxl);
  font-weight: 400;
  font-style: italic;
  margin: 0 0 var(--space-xs);
  letter-spacing: -0.01em;
}

.index-tagline {
  font-family: var(--font-sc);
  font-size: var(--type-sm);
  color: var(--ink-faint);
  letter-spacing: 0.08em;
  text-transform: lowercase;
  margin: 0;
}

.post-list {
  list-style: none;
  padding: 0;
  margin: 0;
  max-width: var(--measure-wide);
}

.post-list-group {
  margin-bottom: var(--space-2xl);
}

.post-list-year {
  font-family: var(--font-sc);
  font-size: var(--type-sm);
  letter-spacing: 0.1em;
  color: var(--ink-faint);
  margin: 0 0 var(--space-md);
  padding-bottom: var(--space-xs);
  border-bottom: 1px solid var(--paper-rule);
  font-feature-settings: "lnum";
}

.post-preview {
  margin: 0 0 var(--space-xl);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--space-sm) var(--space-md);
  align-items: baseline;
}

.post-preview-title {
  font-family: var(--font-body);
  font-size: var(--type-lg);
  font-weight: 500;
  margin: 0;
  line-height: var(--lh-tight);
  grid-column: 1;
}

.post-preview-title a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease);
}

.post-preview-title a:hover {
  border-bottom-color: var(--accent);
}

.post-preview-meta {
  grid-column: 2;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-sc);
  font-size: var(--type-sm);
  color: var(--ink-faint);
  letter-spacing: 0.05em;
  text-transform: lowercase;
  white-space: nowrap;
  font-feature-settings: "lnum";
}

.post-preview-description {
  grid-column: 1 / -1;
  font-size: var(--type-base);
  color: var(--ink-soft);
  margin: var(--space-2xs) 0 0;
  max-width: var(--measure);
  font-style: italic;
}

.lang-pill {
  display: inline-block;
  padding: 0.05em 0.45em;
  border: 1px solid var(--paper-rule);
  border-radius: 1px;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--ink-faint);
  font-feature-settings: "smcp";
}

.read-time {
  color: var(--ink-faint);
}

.post-badge-internal {
  display: inline-block;
  padding: 0.05em 0.45em;
  border: 1px solid var(--state-internal);
  color: var(--state-internal);
  font-family: var(--font-sc);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: lowercase;
  margin-left: var(--space-xs);
  vertical-align: middle;
}

@media (max-width: 600px) {
  .post-preview {
    grid-template-columns: 1fr;
  }
  .post-preview-meta {
    grid-column: 1;
    justify-content: flex-start;
  }
}

/* Featured post gets a little more breathing room */
.post-preview.featured {
  padding: var(--space-lg) 0;
  margin-bottom: var(--space-2xl);
  border-top: 1px solid var(--paper-rule);
  border-bottom: 1px solid var(--paper-rule);
}

.post-preview.featured .post-preview-title {
  font-size: var(--type-xl);
  font-style: italic;
}

.post-preview.featured .post-preview-description {
  font-size: var(--type-lg);
}

/* ------------------------------------------------------------------
 * Tag list on posts
 * ------------------------------------------------------------------ */

.post-tags {
  margin: var(--space-xl) 0 0;
  padding-top: var(--space-md);
  border-top: 1px solid var(--paper-rule);
  font-family: var(--font-sc);
  font-size: var(--type-sm);
  letter-spacing: 0.08em;
  color: var(--ink-faint);
  text-transform: lowercase;
  max-width: var(--measure);
}

.post-tags a {
  color: var(--ink-soft);
  text-decoration: none;
  margin-right: var(--space-sm);
  border-bottom: 1px solid var(--paper-rule);
  transition: border-color var(--dur) var(--ease);
}

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

/* Previous / next navigation */
.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  margin-top: var(--space-2xl);
  padding-top: var(--space-md);
  border-top: 1px solid var(--paper-rule);
  max-width: var(--measure);
  font-family: var(--font-sc);
  font-size: var(--type-sm);
}

.post-nav a {
  color: var(--ink-soft);
  text-decoration: none;
  display: block;
}

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

.post-nav .nav-label {
  display: block;
  color: var(--ink-faint);
  letter-spacing: 0.1em;
  text-transform: lowercase;
  margin-bottom: var(--space-2xs);
}

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

/* ------------------------------------------------------------------
 * Footer
 * ------------------------------------------------------------------ */

footer {
  max-width: 82rem;
  margin: var(--space-4xl) auto 0;
  padding: var(--space-lg) var(--space-md) var(--space-2xl);
  border-top: 1px solid var(--paper-rule);
  color: var(--ink-faint);
  font-family: var(--font-sc);
  font-size: var(--type-sm);
  letter-spacing: 0.06em;
  text-transform: lowercase;
}

footer .footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

footer .navigation a {
  color: inherit;
  text-decoration: none;
  margin-right: var(--space-md);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease);
}

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

footer .colophon {
  font-style: italic;
  color: var(--ink-faint);
}

/* ------------------------------------------------------------------
 * Motion reset for a11y
 * ------------------------------------------------------------------ */

@media (prefers-reduced-motion: reduce) {
  * {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}

/* ------------------------------------------------------------------
 * Utility: screen reader only
 * ------------------------------------------------------------------ */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}