/* ===== FONTS: self-hosted et-book ===== */
@font-face {
  font-family: "et-book";
  src: url("/assets/fonts/et-book/et-book-roman-line-figures.woff") format("woff");
  font-weight: normal;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "et-book";
  src: url("/assets/fonts/et-book/et-book-display-italic-old-style-figures.woff") format("woff");
  font-weight: normal;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: "et-book";
  src: url("/assets/fonts/et-book/et-book-bold-line-figures.woff") format("woff");
  font-weight: bold;
  font-style: normal;
  font-display: swap;
}

/* ===== RESET & TOKENS ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --font-body: "et-book", Palatino, "Palatino Linotype", "Book Antiqua", Georgia, serif;
  --font-ui: "Gill Sans", "Gill Sans MT", Calibri, "Trebuchet MS", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;

  --color-bg: #fffdf2;
  --color-paper: #fbf6e8;
  --color-surface: #f3ead8;
  --color-surface-strong: #eadfca;
  --color-text: #171512;
  --color-heading: #11100d;
  --color-muted: #676052;
  --color-faint: #8a806f;
  --color-border: #d7cab2;
  --color-rule: #cbbda3;
  --color-accent: #9f2f20;
  --color-blue: #2f6f9f;
  --color-green: #6f8068;
  --color-code-bg: #f0e7d5;
  --color-error: #a33a2a;

  --content-width: 48rem;
  --wide-width: 72rem;
  --spacing-page: 1.5rem;
  --radius-sm: 3px;
  --radius-md: 6px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #161412;
    --color-paper: #1f1c18;
    --color-surface: #29241d;
    --color-surface-strong: #332d24;
    --color-text: #e8e1d2;
    --color-heading: #fff8e8;
    --color-muted: #b9ad99;
    --color-faint: #928673;
    --color-border: #4c4234;
    --color-rule: #5a4d3d;
    --color-accent: #e07a63;
    --color-blue: #76abd1;
    --color-green: #9cad87;
    --color-code-bg: #27231c;
    --color-error: #ee8c77;
  }
}

html { font-size: 16px; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-body);
  font-size: 1.25rem;
  line-height: 1.62;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-variant-numeric: oldstyle-nums;
}

::selection { background: color-mix(in srgb, var(--color-blue) 24%, transparent); }

/* ===== TYPOGRAPHY ===== */
h1, h2, h3 {
  color: var(--color-heading);
  font-weight: 400;
  line-height: 1.12;
  text-wrap: balance;
}
h1 { font-size: 3rem; margin: 0 0 1rem; }
h2 { font-size: 2rem; margin: 0 0 0.8rem; }
h3 { font-size: 1.35rem; margin: 0 0 0.35rem; }

p { margin: 0 0 1.1rem; }

a {
  color: inherit;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.16em;
  text-decoration-color: var(--color-rule);
  transition: color 0.15s ease, text-decoration-color 0.15s ease;
}
a:hover { color: var(--color-accent); text-decoration-color: var(--color-accent); }

strong, b { font-weight: bold; }
em, i { font-style: italic; }

.newthought { font-variant: small-caps; font-size: 1.08em; }

code {
  font-family: var(--font-mono);
  font-size: 0.82em;
  background: var(--color-code-bg);
  border: 1px solid color-mix(in srgb, var(--color-border) 65%, transparent);
  border-radius: var(--radius-sm);
  padding: 0.05em 0.28em;
}

pre {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.55;
  background: var(--color-code-bg);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-blue);
  border-radius: var(--radius-sm);
  padding: 1rem 1.15rem;
  overflow-x: auto;
  margin: 1.4rem 0;
}
pre code { background: none; border: 0; padding: 0; font-size: inherit; }

blockquote {
  border-left: 3px solid var(--color-green);
  margin: 1.5rem 0;
  padding-left: 1rem;
  color: var(--color-muted);
}

ul, ol { padding-left: 1.35rem; margin: 0 0 1.1rem; }
li { margin-bottom: 0.35rem; }

hr, .section-divider {
  border: none;
  border-top: 1px solid var(--color-rule);
  margin: 3rem 0;
}

.muted { color: var(--color-muted); font-style: italic; }
.eyebrow,
.section-kicker,
.post-kind,
.post-status,
.entry-meta {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  line-height: 1.2;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0;
}

.section-kicker {
  color: var(--color-blue);
  margin-bottom: 0.35rem;
}

/* ===== LAYOUT ===== */
.site-header {
  border-bottom: 1px solid var(--color-rule);
  background: var(--color-paper);
}

.nav {
  max-width: var(--wide-width);
  margin: 0 auto;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 0.9rem var(--spacing-page);
}

.nav-name {
  font-size: 1.18rem;
  color: var(--color-heading);
  text-decoration: none;
}
.nav-name:hover { color: var(--color-accent); }

.nav-links {
  list-style: none;
  display: flex;
  gap: 1.1rem;
  padding: 0;
  margin: 0;
  flex-wrap: wrap;
}
.nav-links li { margin: 0; }
.nav-links a {
  font-family: var(--font-ui);
  font-size: 0.92rem;
  color: var(--color-muted);
  text-decoration: none;
}
.nav-links a:hover { color: var(--color-accent); }

.main-content {
  max-width: var(--wide-width);
  margin: 0 auto;
  padding: 3rem var(--spacing-page) 4.5rem;
}

.site-footer {
  border-top: 1px solid var(--color-rule);
  max-width: var(--wide-width);
  margin: 0 auto;
  padding: 1.5rem var(--spacing-page) 2rem;
  font-family: var(--font-ui);
  font-size: 0.9rem;
  color: var(--color-muted);
}
.site-footer a { color: var(--color-muted); }
.site-footer a:hover { color: var(--color-accent); }

/* ===== HOME ===== */
.garden-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 340px);
  gap: clamp(3rem, 7vw, 6rem);
  align-items: start;
  padding: 1.1rem 0 4rem;
  border-bottom: 1px solid var(--color-rule);
}

.garden-hero h1 {
  font-size: 3.35rem;
  margin-bottom: 0.35rem;
}

.hero-copy {
  max-width: 50rem;
}

.hero-lede {
  font-size: 1.55rem;
  line-height: 1.35;
  color: var(--color-heading);
  max-width: 43rem;
  margin-bottom: 1.2rem;
}

.profile-bio {
  max-width: 41rem;
  color: var(--color-muted);
  font-size: 1.12rem;
  line-height: 1.58;
}

.profile-photo-wrap {
  justify-self: end;
}

.profile-photo {
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  object-position: center 38%;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  display: block;
}

.profile-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.85rem;
  font-family: var(--font-ui);
  font-size: 0.98rem;
}
.profile-links a { color: var(--color-muted); text-decoration: none; }
.profile-links a:hover { color: var(--color-accent); }
.profile-links a + a {
  border-left: 1px solid var(--color-rule);
  padding-left: 0.85rem;
}

.thread-board,
.entry-ways,
.recent-posts,
.papers {
  margin-top: 4rem;
}

.thread-list {
  list-style: none;
  padding: 0;
  margin: 1.2rem 0 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--color-rule);
}

.thread-item {
  counter-increment: thread;
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr);
  gap: 1.5rem;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--color-rule);
  margin: 0;
}

.thread-label {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-green);
}

.thread-item p {
  grid-column: 2;
  color: var(--color-muted);
  margin: 0;
}

.entry-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin-top: 1.1rem;
  background: var(--color-rule);
  border: 1px solid var(--color-rule);
}

.entry-way {
  min-height: 12rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  padding: 1rem;
  background: var(--color-paper);
  text-decoration: none;
}
.entry-way:hover {
  color: inherit;
  background: var(--color-surface);
}
.entry-way strong {
  font-size: 1.35rem;
  color: var(--color-heading);
  font-weight: 400;
}
.entry-way span:last-child {
  color: var(--color-muted);
  font-size: 1.05rem;
  line-height: 1.45;
}

.page-header {
  max-width: var(--content-width);
  margin-bottom: 2.4rem;
}
.page-intro {
  font-size: 1.35rem;
  line-height: 1.45;
  color: var(--color-muted);
}
.archive-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.1rem;
  font-family: var(--font-ui);
  font-size: 0.95rem;
}
.archive-jump a {
  color: var(--color-muted);
  text-decoration: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.25rem 0.55rem;
}
.archive-jump a:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* ===== BUTTONS AND DEMOS ===== */
.btn {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 0.92rem;
  color: var(--color-text);
  background: var(--color-paper);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.38rem 0.85rem;
  cursor: pointer;
  text-decoration: none;
  transition: color 0.15s ease, border-color 0.15s ease, background-color 0.15s ease;
}
.btn:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background: var(--color-surface);
}
.btn:disabled { opacity: 0.55; cursor: default; }
.btn-secondary { color: var(--color-muted); }

.demo-container {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.2rem;
  margin: 1.7rem 0;
  background: var(--color-paper);
}
.demo-container canvas,
.demo-container iframe,
.demo-container svg { display: block; max-width: 100%; margin: 0 auto; }

.graphon-demo {
  font-family: var(--font-ui);
  font-size: 0.95rem;
  line-height: 1.35;
}

.graphon-panel-grid {
  display: grid;
  gap: 1rem;
  align-items: start;
}

.graphon-panel-grid.two,
.graphon-panel-grid.sampling {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.graphon-panel-grid.three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.graphon-figure-panel {
  margin: 0;
  min-width: 0;
}

.graphon-figure-panel figcaption {
  margin-top: 0.45rem;
  color: var(--color-muted);
  font-size: 0.86rem;
  text-align: center;
}

.graphon-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  align-items: end;
  margin-bottom: 1rem;
}

.graphon-control {
  display: inline-flex;
  flex-direction: column;
  gap: 0.25rem;
  color: var(--color-muted);
  font-size: 0.78rem;
  text-transform: uppercase;
}

.graphon-control select {
  min-width: 9.5rem;
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.38rem 0.5rem;
  font: inherit;
  text-transform: none;
}

.graphon-caption {
  margin: 0.9rem 0 0;
  color: var(--color-muted);
  font-size: 0.95rem;
  line-height: 1.45;
}

.graphon-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 0.75rem;
}

.graphon-metric {
  display: inline-flex;
  gap: 0.4rem;
  align-items: baseline;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.22rem 0.5rem;
  background: var(--color-bg);
  color: var(--color-muted);
}

.graphon-metric strong {
  color: var(--color-heading);
}

.graphon-razborov {
  margin-top: 0.9rem;
}

/* ===== PAPERS ===== */
.paper-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--color-rule);
}

.paper-item {
  padding: 1.2rem 0 1.3rem;
  border-bottom: 1px solid var(--color-rule);
  margin: 0;
}

.paper-title {
  font-size: 1.38rem;
  color: var(--color-heading);
  margin-bottom: 0.15rem;
}
.paper-authors { font-size: 1.05rem; color: var(--color-muted); margin-bottom: 0.05rem; }
.paper-venue { font-size: 1rem; color: var(--color-muted); font-style: italic; margin-bottom: 0.55rem; }

.paper-abstract { margin: 0.4rem 0; }
.paper-abstract summary {
  cursor: pointer;
  font-family: var(--font-ui);
  font-size: 0.92rem;
  color: var(--color-muted);
  user-select: none;
}
.paper-abstract summary:hover { color: var(--color-accent); }

.abstract-body {
  margin-top: 0.55rem;
  font-size: 1.12rem;
  line-height: 1.55;
  color: var(--color-text);
  padding-left: 1rem;
  border-left: 2px solid var(--color-rule);
}

.paper-links { display: flex; gap: 1rem; margin-top: 0.65rem; }
.paper-link {
  font-family: var(--font-ui);
  font-size: 0.9rem;
  color: var(--color-muted);
  text-decoration: none;
  border-bottom: 1px solid var(--color-rule);
}
.paper-link:hover { color: var(--color-accent); border-color: var(--color-accent); }

/* ===== POST LISTS ===== */
.post-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--color-rule);
  margin-top: 1.2rem;
}

.post-list-item {
  padding: 1.15rem 0 1.25rem;
  border-bottom: 1px solid var(--color-rule);
  margin: 0;
}

.post-list-meta,
.post-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem 0.75rem;
  align-items: baseline;
  margin-bottom: 0.35rem;
  color: var(--color-faint);
}

.post-kind {
  color: var(--color-blue);
}

.post-status {
  color: var(--color-green);
}

.post-list-date {
  font-family: var(--font-ui);
  font-size: 0.82rem;
  color: var(--color-faint);
}

.post-list-title {
  display: inline-block;
  font-size: 1.5rem;
  color: var(--color-heading);
  text-decoration: none;
  line-height: 1.2;
  margin-bottom: 0.2rem;
}
.post-list-title:hover { color: var(--color-accent); }

.post-list-summary {
  font-size: 1.12rem;
  color: var(--color-muted);
  margin-bottom: 0.35rem;
  max-width: 44rem;
}

.more-link {
  display: inline-block;
  margin-top: 1.2rem;
  font-family: var(--font-ui);
  font-size: 0.98rem;
  color: var(--color-muted);
  text-decoration: none;
  border-bottom: 1px solid var(--color-rule);
}
.more-link:hover { color: var(--color-accent); border-color: var(--color-accent); }

/* ===== TAGS ===== */
.post-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.25rem;
}

.tag {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-ui);
  font-size: 0.82rem;
  line-height: 1.2;
  color: var(--color-faint);
  text-decoration: none;
  border: 1px solid color-mix(in srgb, var(--color-border) 75%, transparent);
  border-radius: var(--radius-sm);
  padding: 0.16rem 0.38rem;
  background: color-mix(in srgb, var(--color-paper) 75%, transparent);
}
.tag:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.tag-heading {
  font-size: 1rem;
  color: var(--color-blue);
  background: transparent;
}

.tag-index {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  max-width: var(--content-width);
}
.tag-index li { margin: 0; }

/* ===== BLOG POST ===== */
.post {
  max-width: var(--content-width);
  margin: 0 auto;
}

.post-header {
  margin-bottom: 2.3rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--color-rule);
}
.post-title {
  font-size: 3rem;
  margin-bottom: 0.75rem;
}

.post-meta {
  font-family: var(--font-ui);
  font-size: 0.86rem;
  margin-bottom: 0;
}

.course-question-form {
  font-family: var(--font-ui);
  font-size: 0.86rem;
  margin-top: 0.6rem;
  margin-bottom: 0;
}
.course-question-form a {
  color: var(--color-muted);
}
.course-question-form a:hover {
  color: var(--color-accent);
}

.post-content {
  font-size: 1.28rem;
  line-height: 1.66;
}
.post-content h2 { margin-top: 2.5rem; }
.post-content h3 { margin-top: 1.9rem; }
.post-content img {
  max-width: 100%;
  height: auto;
  margin: 1.6rem 0;
  border-radius: var(--radius-sm);
}
.post-content > p:first-of-type { margin-top: 0; }
.post-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 1rem;
}
.post-content th,
.post-content td {
  border-bottom: 1px solid var(--color-rule);
  padding: 0.45rem 0.35rem;
  text-align: left;
}

.post-content .katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.4rem 0;
}

.post-nav {
  margin-top: 3.3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--color-rule);
}
.post-nav a {
  font-family: var(--font-ui);
  font-size: 0.96rem;
  color: var(--color-muted);
  text-decoration: none;
}
.post-nav a:hover { color: var(--color-accent); }

/* ===== SEARCH ===== */
.search-input {
  width: 100%;
  max-width: var(--content-width);
  display: block;
  font-family: var(--font-body);
  font-size: 1.25rem;
  padding: 0.65rem 0.2rem;
  border: none;
  border-bottom: 2px solid var(--color-rule);
  background: transparent;
  color: var(--color-text);
  margin-bottom: 2rem;
  outline: none;
  transition: border-color 0.15s ease;
}
.search-input::placeholder { color: var(--color-faint); font-style: italic; }
.search-input:focus { border-color: var(--color-blue); }

.search-results {
  max-width: var(--content-width);
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
}
.search-result { padding: 0; }

.search-result-title {
  font-size: 1.45rem;
  color: var(--color-heading);
  text-decoration: none;
  display: inline-block;
  margin-bottom: 0.15rem;
}
.search-result-title:hover { color: var(--color-accent); }
.search-result-summary { font-size: 1.1rem; color: var(--color-muted); margin-bottom: 0.25rem; }

/* ===== TEACHING ===== */
.course {
  max-width: var(--content-width);
  margin: 0 auto;
}

.course-section {
  margin-top: 2.5rem;
}
.course-section h2 {
  font-size: 1.55rem;
  margin-bottom: 0.75rem;
}

.course-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 1rem;
  margin-top: 0.5rem;
}
.course-table th {
  font-family: var(--font-ui);
  font-size: 0.82rem;
  text-transform: uppercase;
  color: var(--color-muted);
  font-weight: normal;
  border-bottom: 1px solid var(--color-rule);
  padding: 0.4rem 0.4rem;
  text-align: left;
}
.course-table td {
  padding: 0.45rem 0.4rem;
  text-align: left;
  vertical-align: top;
}

.course-oh-list {
  list-style: none;
  padding: 0;
  margin: 0.5rem 0 0;
}
.course-oh-list li {
  display: flex;
  gap: 1.5rem;
  padding: 0.3rem 0;
  margin: 0;
  font-size: 1.1rem;
}
.course-oh-day { min-width: 13rem; }
.course-oh-location { color: var(--color-muted); }

.course-plan-list {
  list-style: none;
  padding: 0;
  margin: 0.5rem 0 0;
}
.course-plan-list li {
  padding: 0.3rem 0;
  margin: 0;
  font-size: 1.1rem;
}
.course-plan-date {
  font-family: var(--font-ui);
  font-size: 0.88rem;
  color: var(--color-faint);
}

.course-notes { margin-top: 2.5rem; }

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
  .entry-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .graphon-panel-grid.three { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  html { font-size: 15px; }
  .main-content { padding-top: 2rem; }
  .garden-hero {
    grid-template-columns: 1fr;
    gap: 1.4rem;
  }
  .profile-photo-wrap { justify-self: start; order: -1; }
  .profile-photo { width: 160px; height: 200px; }
  .garden-hero h1,
  .post-title { font-size: 2.55rem; }
  .hero-lede,
  .page-intro { font-size: 1.25rem; }
  .thread-item {
    grid-template-columns: 1fr;
    gap: 0.35rem;
  }
  .thread-item p { grid-column: auto; }
  .entry-grid { grid-template-columns: 1fr; }
  .entry-way { min-height: 0; }
  .graphon-panel-grid.two,
  .graphon-panel-grid.sampling { grid-template-columns: 1fr; }
  .graphon-controls { align-items: stretch; }
  .graphon-controls .btn,
  .graphon-control,
  .graphon-control select { width: 100%; }
}

@media (max-width: 480px) {
  :root { --spacing-page: 1rem; }
  .nav { align-items: flex-start; }
  .nav-links { gap: 0.8rem; }
  h1 { font-size: 2.4rem; }
  h2 { font-size: 1.7rem; }
}