/* Aydin Mohseni. Layout ported from exproof.ai (assets/site.css): a three-zone Swiss grid.
   Label rail | text column (about 65 characters, CMU Serif) | margin notes (Tufte).
   Paper ground by default; Night mode uses the exproof.ai palette. Every face is Computer Modern.
   A faint paper grain sits behind the page; text, controls and tables stay crisp.
   Below 860px the rail sits above each section and margin notes open in place. */

/* ---------- Fonts: Computer Modern (CMU, SIL OFL), self-hosted ----------
   CMU Serif: weight 400 is the file named 500, weight 700 the file named 700.
   CMU Sans Serif has one weight; it serves 400 and 500 so labels never get synthetic bold. */
@font-face { font-family: "CMU Serif"; src: url("../fonts/cmu-serif-500-roman.woff2") format("woff2"); font-weight: 400 500; font-style: normal; font-display: swap; }
@font-face { font-family: "CMU Serif"; src: url("../fonts/cmu-serif-500-italic.woff2") format("woff2"); font-weight: 400 500; font-style: italic; font-display: swap; }
@font-face { font-family: "CMU Serif"; src: url("../fonts/cmu-serif-700-roman.woff2") format("woff2"); font-weight: 600 700; font-style: normal; font-display: swap; }
@font-face { font-family: "CMU Serif"; src: url("../fonts/cmu-serif-700-italic.woff2") format("woff2"); font-weight: 600 700; font-style: italic; font-display: swap; }
@font-face { font-family: "CMU Sans Serif"; src: url("../fonts/cmu-sans-serif-500-roman.woff2") format("woff2"); font-weight: 400 500; font-style: normal; font-display: swap; }
@font-face { font-family: "CMU Sans Serif"; src: url("../fonts/cmu-sans-serif-500-italic.woff2") format("woff2"); font-weight: 400 500; font-style: italic; font-display: swap; }
@font-face { font-family: "CMU Typewriter Text"; src: url("../fonts/cmu-typewriter-text-500-roman.woff2") format("woff2"); font-weight: 400 500; font-style: normal; font-display: swap; }

/* ---------- Tokens ---------- */
:root {
  /* Day (default): ink on paper. */
  --bg: #fcfcfa;          /* paper */
  --fg: #141413;          /* ink */
  --fg-2: #5d5d58;        /* graphite: secondary text, metadata, labels */
  --rule: #e2e2dc;        /* hairlines inside tables and the citation box */
  --rule-strong: #a9a9a2; /* masthead line (at half strength), button borders */
  --red: #b0122b;         /* marks, the current page, active states */
  --red-bright: #d11c3d;  /* hover, the wordmark delta, large accent text */
  --green: #1a7f4e;       /* a found or converged path in models only */
  --chalk: #2b2b29;       /* model strokes */
  --header-bg: rgba(252, 252, 250, 0.96);   /* dark ink shows through paper far more than light text through black, so day needs more than exproof's 0.88 */
  --code-bg: #f3f3ef;
  --mark: #f3e3a2;        /* review-mode highlight */
  --sel-fg: #fcfcfa;
  --grain-opacity: 0.04;
  --grain: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='280' height='280'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1.6 0 0 0 -0.45'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23g)'/%3E%3C/svg%3E");

  --serif: "CMU Serif", "Latin Modern Roman", "Computer Modern", Georgia, serif;
  --sans: "CMU Sans Serif", "Latin Modern Sans", "Computer Modern Sans", "Helvetica Neue", Arial, sans-serif;
  --mono: "CMU Typewriter Text", "Latin Modern Mono", "Computer Modern Typewriter", ui-monospace, Menlo, Consolas, monospace;
  --math: "STIX Two Math", "Cambria Math", "Latin Modern Math", var(--serif);

  --rail: 8.5rem;
  --gap: 2.5rem;
  --margin: 15rem;
  --measure: 34rem;
  color-scheme: light;
}
/* Night: exactly the exproof.ai palette. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #050505; --fg: #f5f5f2; --fg-2: #b8b8b3; --rule: #2c2c2a; --rule-strong: #6c6c68;
    --red: #b0122b; --red-bright: #d11c3d; --green: #1fa463; --chalk: #d8d8d2;
    --header-bg: rgba(5, 5, 5, 0.88); --code-bg: #111110; --mark: #4a3a10; --sel-fg: #f5f5f2;
    --grain-opacity: 0.025;
    --grain: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='280' height='280'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 1.6 0 0 0 -0.45'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23g)'/%3E%3C/svg%3E");
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #050505; --fg: #f5f5f2; --fg-2: #b8b8b3; --rule: #2c2c2a; --rule-strong: #6c6c68;
  --red: #b0122b; --red-bright: #d11c3d; --green: #1fa463; --chalk: #d8d8d2;
  --header-bg: rgba(5, 5, 5, 0.88); --code-bg: #111110; --mark: #4a3a10; --sel-fg: #f5f5f2;
  --grain-opacity: 0.025;
  --grain: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='280' height='280'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 1.6 0 0 0 -0.45'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23g)'/%3E%3C/svg%3E");
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { font-size: 17px; -webkit-text-size-adjust: 100%; text-size-adjust: 100%; background: var(--bg); }
@media (min-width: 1200px) { html { font-size: 18px; } }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--serif);
  font-size: 1.15rem;
  line-height: 1.5;
  font-kerning: normal;
  font-variant-ligatures: common-ligatures;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}
/* Computer Modern has thin hairlines. Grayscale smoothing thins them further on dark-on-light,
   so it is used only in Night, where it keeps light text from blooming. */
:root[data-theme="dark"] body { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) body { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; } }
body::before { content: ""; position: fixed; inset: 0 0 auto; height: env(safe-area-inset-top, 0px); z-index: 10; background: var(--bg); }

/* Chalk on paper: a fixed, static grain behind the page. Never animated. */
body::after {
  content: ""; position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image: var(--grain); background-size: 280px 280px; opacity: var(--grain-opacity);
}

/* Full-page model behind the content (the chaos background), mounted by background.js. */
.model-background { position: fixed; inset: 0; width: 100vw; height: 100vh; z-index: 0; pointer-events: none; overflow: hidden; display: block; }

.page {
  position: relative; z-index: 1;
  max-width: calc(var(--rail) + var(--gap) + var(--measure) + 2.5rem + var(--margin));
  margin: 0 auto;
  padding-left: max(24px, env(safe-area-inset-left, 0px));
  padding-right: max(24px, env(safe-area-inset-right, 0px));
  padding-block: 0 4rem;
}

a { color: inherit; text-decoration: none; transition: color 120ms ease; }
a:hover { color: var(--red-bright); }
/* Links inside running text are red, as on danielherrmann.ca, so a reader can tell they are links.
   Titles, author lines, menus and link rows keep their own colors. */
.bio a, .lede a, .erdos-path a, .body > p:not([class]) a, figcaption a { color: var(--red-bright); }
.bio a:hover, .lede a:hover, .erdos-path a:hover, .body > p:not([class]) a:hover, figcaption a:hover {
  color: var(--red-bright); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:focus-visible, button:focus-visible, summary:focus-visible, label:focus-visible, input:focus-visible, select:focus-visible, [tabindex]:focus-visible { outline: 2px solid var(--red-bright); outline-offset: 2px; }
::selection { background: var(--red); color: var(--sel-fg); }
img { height: auto; }
code, kbd, samp { font-family: var(--mono); font-size: 0.9em; }

main:focus { outline: none; }   /* focused only as the skip link's target */
.skip { position: absolute; left: 0.5rem; top: -3rem; z-index: 30; padding: 0.4rem 0.7rem; background: var(--fg); color: var(--bg); font: 0.78rem var(--sans); }
.skip:focus { top: 0.5rem; color: var(--bg); }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }

/* ---------- Masthead ---------- */
.masthead {
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 5;
  display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 0.6rem 2rem;
  padding-block: 1.15rem 0.95rem;
  background: var(--header-bg);
  -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px);
  border-bottom: 1px solid color-mix(in srgb, var(--rule-strong) 50%, transparent);  /* --rule-strong at half strength */
}
/* Wordmark: the name in CMU Serif. On hover it turns red. */
/* The masthead's translucent ground would hide the grain; it carries its own copy, fixed to the
   viewport so the two layers line up. */
.masthead::before {
  content: ""; position: absolute; inset: 0; z-index: -1; pointer-events: none;
  background-image: var(--grain); background-size: 280px 280px; background-attachment: fixed; opacity: var(--grain-opacity);
}
.wordmark { display: inline-flex; align-items: baseline; color: var(--fg); font-size: 1.62rem; line-height: 0.92; white-space: nowrap; letter-spacing: -0.005em; }
.wordmark .delta { color: var(--red-bright); margin-right: 0.3em; transition: color 160ms ease; }
.wordmark .name { transition: color 160ms ease; }
.wordmark:hover, .wordmark:focus-visible { color: var(--red-bright); }
.brand-mark { font-size: 1.2rem; color: var(--red-bright); line-height: 1; }
.nav { display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.35rem 1.5rem; font-family: var(--sans); font-size: 0.78rem; letter-spacing: 0.05em; }
.nav a { color: var(--fg-2); padding-block: 0.15rem; }
.nav a:hover { color: var(--fg); }
.nav .nav-xp { color: var(--fg); }
.nav .nav-xp:hover, .nav .nav-xp:focus-visible { color: var(--red-bright); }
.nav a[aria-current="page"] { color: var(--fg); box-shadow: inset 0 -1px 0 var(--red); }
.exists { font-family: var(--math); font-size: 1.04em; line-height: 1; color: var(--red-bright); margin-right: 0.02em; }
.theme-toggle {
  font: inherit; letter-spacing: inherit; color: var(--fg-2); background: none; border: 0; cursor: pointer;
  padding: 0.15rem 0; margin: 0;
}
.theme-toggle:hover { color: var(--fg); }
/* A half-filled disc before the word, as on danielherrmann.ca. */
.theme-toggle::before {
  content: ""; display: inline-block; width: 0.72em; height: 0.72em; margin-right: 0.4em; vertical-align: -0.06em;
  border: 1px solid currentColor; border-radius: 50%; background: linear-gradient(90deg, currentColor 50%, transparent 50%);
}
@media (max-width: 560px) {
  .masthead { position: relative; }
  .nav .theme-toggle { position: absolute; right: 0; top: 1.05rem; padding: 0.3rem 0.7rem; border: 1px solid var(--rule); border-radius: 999px; }
}
.theme-toggle .to-day { display: none; }
:root[data-theme="dark"] .theme-toggle .to-day { display: inline; }
:root[data-theme="dark"] .theme-toggle .to-night { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .to-day { display: inline; }
  :root:not([data-theme="light"]) .theme-toggle .to-night { display: none; }
}

/* The Erdős path on About: its own centered line in the sans face. */
.erdos-path { text-align: center; font-family: var(--sans); font-size: 0.95rem; letter-spacing: 0.02em; color: var(--fg); }


/* ---------- Hero and page heads ---------- */
.hero {
  display: grid; grid-template-columns: var(--rail) minmax(0, 1fr); column-gap: var(--gap);
  padding-block: 5.5rem 4.5rem;
}
.hero { --h1: clamp(2.1rem, 5vw, 3.6rem); }
/* The eyebrow's capitals line up with the capitals of the title's first line. In CMU Serif at
   line-height 1.08 the cap line sits 0.1995 of the title's size below its box; the eyebrow's
   cap line sits 0.259rem below its own (CMU Sans Serif, 0.68rem at line-height 1.5). */
.hero .eyebrow { grid-column: 1; padding-top: calc(var(--h1) * 0.1995 - 0.259rem); }
.hero h1 {
  grid-column: 2; margin: 0; max-width: 22em;
  font-weight: 400; font-size: var(--h1); line-height: 1.08; letter-spacing: -0.01em;
  text-wrap: balance;
}
.hero h1 em { font-style: italic; color: var(--red-bright); }
.hero > :not(.eyebrow) { grid-column: 2; }
.hero .lede { max-width: var(--measure); margin: 1.8rem 0 0; color: var(--fg-2); font-size: 1.18rem; }
.hero .who { margin: 1.8rem 0 0; font-family: var(--sans); font-size: 0.78rem; color: var(--fg-2); line-height: 1.7; }
.hero .who b { color: var(--fg); font-weight: 500; }
.hero .who .tag { font-size: 0.64rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--fg); margin-right: 0.35rem; }
.hero .who .nw { white-space: nowrap; }
.page-head { padding-block: 4rem 3rem; }
.page-head { --h1: clamp(1.9rem, 4vw, 2.7rem); }

/* Home intro: a portrait beside the opening text. The eyebrow aligns with the top of the photo. */
.intro { display: grid; grid-template-columns: 9rem minmax(0, 1fr); column-gap: 2rem; align-items: start; max-width: calc(var(--measure) + 11rem); }
.intro-photo { display: block; width: 9rem; height: 9rem; border-radius: 50%; object-fit: cover; }
.intro-text { min-width: 0; }
.intro-text > *:first-child { margin-top: 0; }
.intro .tagline { font-size: 1.62rem; line-height: 1.2; margin: 0 0 0.9rem; }
.intro .bio { color: var(--fg); margin: 0 0 1rem; }
.hero:has(> .intro) .eyebrow { padding-top: 0; }
.hero > .intro { padding-top: 0.265rem; }   /* the eyebrow's capitals meet the top of the photo */
.home-hero { padding-bottom: 2.575rem; }   /* 25% less space before the first section (7.7rem to 5.8rem) */

.eyebrow, .label {
  font-family: var(--sans); font-size: 0.68rem; font-weight: 500; letter-spacing: 0.12em; text-transform: uppercase; color: var(--fg-2);
  line-height: 1.5; margin: 0;
}

/* ---------- Sections ----------
   No rules between sections. Each section ends var(--tail) above its lower edge. A closing note
   (.more as the last element of a section body) sits midway between the element above it and that
   lower edge: var(--tail) above, var(--tail) below. */
:root { --tail: 1.4rem; }
.body > .more:last-child { margin-top: var(--tail); margin-bottom: 0; }

.section {
  display: grid; grid-template-columns: var(--rail) minmax(0, 1fr); column-gap: var(--gap);
  padding-block: 3.2rem var(--tail);
}
.section > .label { position: sticky; top: calc(env(safe-area-inset-top, 0px) + 4.6rem); align-self: start; padding-top: var(--label-pt); }
/* Link targets stop just below the pinned menu, level with a pinned section label. */
[id] { scroll-margin-top: calc(env(safe-area-inset-top, 0px) + 4.6rem); }
main > .section[id] { scroll-margin-top: calc(env(safe-area-inset-top, 0px) + 1.4rem); }
.work[id] { scroll-margin-top: calc(env(safe-area-inset-top, 0px) + 4.6rem - 1.35rem); }   /* less the entry's top padding */
.featured li[id] { scroll-margin-top: calc(env(safe-area-inset-top, 0px) + 4.6rem - 1rem); }
.work[id]:first-child, .featured li[id]:first-child { scroll-margin-top: calc(env(safe-area-inset-top, 0px) + 4.6rem); }
/* Cap-line alignment. The tops of the capitals in a rail label line up with the tops of the
   capitals in the first line beside it (or the top of a figure or photo). The label's cap line
   sits 0.259rem below its box; each kind of first element puts its cap line a fixed distance below
   its own box (CMU Serif: cap height 0.683, ascent 0.935, descent 0.25 of the size). The label is
   pushed down by the difference. Recheck after changing any type size. */
.section { --label-pt: 0.212rem; }                                                           /* body text 1.15rem/1.5 */
.section:has(> .body > .question:first-child) { --label-pt: 0.182rem; }
.section:has(> .body > .summary:first-child) { --label-pt: 0.202rem; }
.section:has(> .body > h3:first-child) { --label-pt: 0.107rem; }
.section:has(> .body > h2:first-child) { --label-pt: 0.195rem; }
.section:has(> .body > .featured:first-child) { --label-pt: 0.119rem; }
.section:has(> .body > .areas:first-child) { --label-pt: 0.097rem; }
.section:has(> .body > :is(.works, .timeline):first-child) { --label-pt: 0.100rem; }
.section:has(> .body > .pair:first-child) { --label-pt: 0.125rem; }
.section:has(> .body > .people:first-child) { --label-pt: 0; }
.section:has(> .body > .people:first-child > .person:first-child > .person-head > .person-id:first-child) { --label-pt: 0.125rem; }   /* no portrait: the name (1.35rem/1.25) leads */
.section:has(> .body > .names:first-child) { --label-pt: 0.102rem; }
.section:has(> .body > .verse:first-child) { --label-pt: 0.183rem; }
.section:has(> .body > .cards:first-child) { --label-pt: 0; }
.section:has(> .body > :is(figure, .gallery):first-child) { --label-pt: 0; }
.section:has(> .body > .lead:first-child) { --label-pt: 0.218rem; }
/* A section that opens with a figure, image grid or portraits: the label's capitals meet the top edge. */
.body > :is(figure, .cards, .gallery, .people):first-child { margin-top: 0.265rem; }
.body > .people:first-child:has(> .person:first-child > .person-head > .person-id:first-child) { margin-top: 0; }

/* Zone rule. In a text section only .sidenote and .marginnote enter the margin column. A wide
   section has no margin column and may not contain margin notes. No other negative margins. */
.body { padding-right: calc(var(--margin) + 2.5rem); min-width: 0; counter-reset: sidenote; }
.body > *, .body figure, .body table, .body img, .body pre, .body canvas, .body svg { max-width: 100%; }
/* Running text keeps the 34rem measure at every width (exproof.ai lets it run full width between
   560 and 860px; here it is capped). Classed lists and grids keep their own widths. */
.body > :is(p, blockquote, ul:not([class]), ol:not([class]), dl:not([class])) { max-width: min(100%, var(--measure)); }
.body * { min-width: 0; }
.section--wide .body { padding-right: 0; }
.section--wide .sidenote, .section--wide .marginnote, .section--wide .margin-toggle { display: none; }
.label, .eyebrow, .meta-line, .work-meta, .role, .addr, .related { overflow-wrap: anywhere; }

/* A formal statement set in the text: italic, indented, variables upright. */
.scheme { font-style: italic; font-size: 1.24rem; line-height: 1.45; margin: 1.4rem 0 1.5rem; padding-left: 1.4rem; }
.scheme var, .body var { font-family: var(--serif); }
.body p var { font-style: italic; }
.body .scheme var { font-style: normal; }
.body > *:first-child { margin-top: 0; }

h1, h2, h3, h4 { font-weight: 400; }
h2 { font-size: 1.75rem; line-height: 1.2; margin: 0 0 0.9rem; text-wrap: balance; }
h3 { font-style: italic; font-size: 1.3rem; line-height: 1.25; margin: 2.2rem 0 0.6rem; }
h2.label, h3.label { font-size: 0.68rem; font-style: normal; line-height: 1.5; margin: 0; text-wrap: wrap; }
p, ul, ol, dl, blockquote { max-width: var(--measure); margin: 0 0 1.1rem; }
.body ul:not([class]), .body ol:not([class]) { padding-left: 1.2rem; }
.body :is(ul, ol):not([class]) > li + li { margin-top: 0.3rem; }   /* plain lists only; grids and styled lists keep their own spacing */
strong, b { font-weight: 700; }
.secondary { color: var(--fg-2); }
.lead { font-size: 1.24rem; line-height: 1.45; }
.more { font-family: var(--sans); font-size: 0.76rem; letter-spacing: 0.04em; }

.block + .block { margin-top: 3rem; padding-top: 2.6rem; }
.question { font-size: 1.32rem; line-height: 1.35; margin-bottom: 1.2rem; }

/* Entries with a one- or two-sentence summary, then an optional "More" that opens in place. */
.summary { font-size: 1.2rem; line-height: 1.45; margin-bottom: 0.9rem; }
details.expand { margin: 0 0 0.4rem; }
details.expand > summary {
  list-style: none; cursor: pointer; display: inline-flex; align-items: center; gap: 0.5rem;
  font: 500 0.7rem var(--sans); letter-spacing: 0.1em; text-transform: uppercase; color: var(--fg-2);
  padding-block: 0.3rem;
}
details.expand > summary::-webkit-details-marker { display: none; }
details.expand > summary::before { content: "+"; font-size: 0.95rem; line-height: 1; color: var(--red-bright); width: 0.7rem; }
details.expand[open] > summary::before { content: "\2212"; }
details.expand > summary:hover { color: var(--fg); }
details.expand[open] > summary { color: var(--fg); margin-bottom: 1rem; }
.expand-body > *:first-child { margin-top: 0; }
.meta-line { font-family: var(--sans); font-size: 0.74rem; letter-spacing: 0.02em; color: var(--fg-2); margin: -0.4rem 0 1.4rem; }
.meta-line b { font-weight: 500; color: var(--fg); }
.related { list-style: none; padding: 0; font-family: var(--sans); font-size: 0.8rem; display: flex; flex-wrap: wrap; gap: 0.3rem 1.4rem; }
.related .label { flex-basis: 100%; margin-bottom: 0.2rem; }

/* Quotation and verse. Verse keeps its line breaks. */
blockquote { margin-left: 0; padding-left: 1.4rem; }
blockquote footer, .attribution { font-family: var(--sans); font-size: 0.74rem; letter-spacing: 0.02em; color: var(--fg-2); margin-top: 0.6rem; }
.verse { white-space: pre-line; font-size: 1.08rem; line-height: 1.5; }
.verse p { margin: 0 0 1rem; }

/* ---------- Grids of short, parallel items (wide sections) ---------- */
.areas { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0 1.6rem; }
.areas--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.area { min-width: 0; }
.area h3 { font-style: normal; font-size: 1.25rem; margin: 0 0 0.45rem; }
.area h3 a:hover { color: var(--red-bright); }
.area p { font-size: 1rem; line-height: 1.38; color: var(--fg-2); margin: 0; }

.featured { list-style: none; padding: 0; margin: 0; max-width: none; }
.featured li { padding-block: 1rem; }
.featured li:first-child { padding-top: 0; }
.featured .t { font-size: 1.22rem; line-height: 1.3; display: block; margin-bottom: 0.2rem; }
.featured .t a:hover { color: var(--red-bright); }
.featured .d { color: var(--fg-2); font-size: 1rem; display: block; }

/* Cards: models and similar items with a thumbnail. */
.cards { list-style: none; padding: 0; margin: 0; max-width: none; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 2.2rem 1.8rem; }
.card { min-width: 0; display: flex; flex-direction: column; }
.card-thumb { display: block; width: 100%; aspect-ratio: 16 / 10; object-fit: cover; border: 1px solid var(--rule); background: var(--code-bg); margin: 0 0 0.8rem; }
.card h3 { font-style: normal; font-size: 1.2rem; line-height: 1.28; margin: 0 0 0.35rem; }
.card p { font-size: 0.98rem; line-height: 1.4; color: var(--fg-2); margin: 0 0 0.6rem; }
.card .work-links { margin-top: auto; }

/* Gallery: sketchbook images. */
.gallery { list-style: none; padding: 0; margin: 0; max-width: none; display: grid; grid-template-columns: repeat(auto-fill, minmax(12rem, 1fr)); gap: 1.6rem; }
.gallery figure { margin: 0; }
.gallery img { display: block; width: 100%; border: 1px solid var(--rule); }

/* A dated list (appointments, education): date in a narrow column, entry beside it. */
.timeline { display: grid; grid-template-columns: 7.5rem minmax(0, 1fr); column-gap: 1.6rem; row-gap: 0.7rem; margin: 0 0 1.1rem; max-width: none; }
.timeline dt { font-family: var(--sans); font-size: 0.72rem; line-height: 1.6; color: var(--fg); font-weight: 500; padding-top: 0.049rem; font-variant-numeric: tabular-nums; }
.timeline dd { margin: 0; font-size: 1.05rem; line-height: 1.4; }
.timeline dd .secondary { font-size: 0.95rem; }

.problems { list-style: none; padding: 0; margin: 0; max-width: none; counter-reset: problem; }
.problems li { counter-increment: problem; display: grid; grid-template-columns: 3rem minmax(0, 1fr); padding-block: 0.75rem; font-size: 1.18rem; line-height: 1.35; }
.problems li::before { content: counter(problem, decimal-leading-zero); font-family: var(--mono); font-size: 0.72rem; color: var(--red-bright); padding-top: 0.35rem; }

/* ---------- Tufte margin notes ----------
   Markup (as on exproof.ai):
   <label for="sn-1" class="margin-toggle sidenote-number"></label><input type="checkbox" id="sn-1" class="margin-toggle"><span class="sidenote">...</span>
   <label for="mn-1" class="margin-toggle"></label><input type="checkbox" id="mn-1" class="margin-toggle"><span class="marginnote">...</span> */
.sidenote, .marginnote {
  float: right; clear: right; position: relative;
  width: var(--margin); margin-right: calc(-1 * (var(--margin) + 2.5rem)); margin-top: 0.3rem; margin-bottom: 1rem;
  font-size: 0.86rem; line-height: 1.38; color: var(--fg-2);
}
.sidenote-number { counter-increment: sidenote; }
.sidenote-number::after, .sidenote::before {
  font-family: var(--sans); font-size: 0.62rem; font-weight: 500; color: var(--red-bright); position: relative; vertical-align: super; line-height: 0;
}
.sidenote-number::after { content: counter(sidenote); left: 0.08em; }
.sidenote::before { content: counter(sidenote) " "; top: -0.1rem; }
input.margin-toggle { display: none; }
label.margin-toggle:not(.sidenote-number) { display: none; }

/* ---------- Figures ---------- */
figure { margin: 2rem 0 2.2rem; max-width: 100%; }
figure img { display: block; max-width: 100%; }
figcaption { font-size: 0.86rem; line-height: 1.38; color: var(--fg-2); max-width: var(--measure); margin-top: 0.9rem; }
figcaption .label { margin-right: 0.5rem; color: var(--fg); }

/* ---------- Live models ----------
   <figure class="model" data-model="name"> is mounted by site.js, which imports
   /assets/js/models/<name>.js and calls mount(figure.querySelector(".model-mount"), options).
   The model builds its own canvas, controls and "How it works". These rules give any model a
   consistent, minimal look: CMU Sans Serif controls, small, hairline borders. */
.model { position: relative; }
.model-mount { position: relative; width: 100%; min-width: 0; }
.model:not([data-mounted="true"]) .model-mount { aspect-ratio: var(--aspect, 4 / 3); }
.model-mount canvas { display: block; width: 100%; max-width: 100%; touch-action: pan-y; }
.model-fallback { font-family: var(--sans); font-size: 0.8rem; color: var(--fg-2); margin: 0; padding-top: 1rem; }
.model[data-mounted="error"] .model-mount { aspect-ratio: auto; }
.model-controls, .model .controls {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem 1.2rem;
  margin: 0.8rem 0 0; font-family: var(--sans); font-size: 0.72rem; letter-spacing: 0.03em; color: var(--fg-2);
}
.model-controls label, .model .controls label { display: inline-flex; align-items: center; gap: 0.45rem; }
.model button, .btn {
  font: 500 0.7rem var(--sans); letter-spacing: 0.08em; text-transform: uppercase; line-height: 1.2;
  background: transparent; color: var(--fg-2); border: 1px solid var(--rule-strong); padding: 0.35rem 0.7rem; cursor: pointer;
  border-radius: 0; transition: color 120ms ease, border-color 120ms ease;
}
.model button:hover, .btn:hover { color: var(--fg); border-color: var(--fg-2); }
.model button[aria-pressed="true"], .btn[aria-pressed="true"], .btn--active { color: var(--fg); border-color: var(--red); box-shadow: inset 0 -2px 0 var(--red); }
.model button:disabled, .btn:disabled { opacity: 0.5; cursor: default; }
a.btn { display: inline-block; text-decoration: none; }
.segmented { display: inline-flex; }
/* Pause/Play and the restart action, first in every model's control row, never split. */
.model-actions { display: inline-flex; gap: 0.5rem; flex: none; white-space: nowrap; }
.segmented > button + button { border-left: 0; }
.model input[type="range"] { accent-color: var(--red); width: 7rem; vertical-align: middle; }
.model select { font: 0.72rem var(--sans); color: var(--fg); background: var(--bg); border: 1px solid var(--rule-strong); padding: 0.2rem 0.4rem; }
.model input[type="checkbox"], .model input[type="radio"] { accent-color: var(--red); }
.model output, .model .readout { font-family: var(--sans); font-variant-numeric: tabular-nums; color: var(--fg); }
/* "How it works": a disclosure under the model, like details.expand. */
.model details, details.how { margin: 0.9rem 0 0; }
.model details > summary, details.how > summary {
  list-style: none; cursor: pointer; display: inline-flex; align-items: center; gap: 0.5rem;
  font: 500 0.7rem var(--sans); letter-spacing: 0.1em; text-transform: uppercase; color: var(--fg-2); padding-block: 0.3rem;
}
.model details > summary::-webkit-details-marker, details.how > summary::-webkit-details-marker { display: none; }
.model details > summary::before, details.how > summary::before { content: "+"; font-size: 0.95rem; line-height: 1; color: var(--red-bright); width: 0.7rem; }
.model details[open] > summary::before, details.how[open] > summary::before { content: "\2212"; }
.model details > summary:hover, details.how > summary:hover { color: var(--fg); }
.model details[open] > summary, details.how[open] > summary { color: var(--fg); margin-bottom: 0.6rem; }
.model details > :not(summary), details.how > :not(summary) { font-size: 1rem; line-height: 1.45; color: var(--fg); max-width: var(--measure); }
.model details p, details.how p { margin: 0 0 0.8rem; }
.model-desc { font-size: 0.86rem; line-height: 1.38; color: var(--fg-2); margin: 0.6rem 0 0; }

/* ---------- Tables ---------- */
.compare { width: 100%; border-collapse: collapse; font-size: 0.98rem; line-height: 1.35; }
.compare th, .compare td { text-align: left; vertical-align: top; padding: 0.6rem 1rem 0.6rem 0; border-bottom: 1px solid var(--rule); }
.compare thead th { font-family: var(--sans); font-size: 0.66rem; font-weight: 500; letter-spacing: 0.1em; text-transform: uppercase; color: var(--fg-2); border-bottom: 1px solid var(--fg); }
.compare tbody th { font-weight: 400; color: var(--fg-2); font-style: italic; width: 30%; }
.compare td.num, .compare th.num { text-align: right; font-variant-numeric: tabular-nums; }
.table-wrap { overflow-x: auto; }

/* ---------- Status marks ---------- */
.status { display: inline-flex; align-items: center; gap: 0.4rem; font-family: var(--sans); font-size: 0.72rem; color: var(--fg-2); white-space: nowrap; }
.status::before { content: ""; width: 0.42rem; height: 0.42rem; border: 1px solid var(--rule-strong); border-radius: 50%; flex: none; }
.status.active::before { background: var(--red); border-color: var(--red); }
.status.out::before { background: var(--fg); border-color: var(--fg); }

/* ---------- Works (Research page) ---------- */
.filters { display: flex; flex-wrap: wrap; gap: 0.4rem; margin: 0 0 1.2rem; max-width: none; }
.filters button {
  font: 500 0.7rem var(--sans); letter-spacing: 0.08em; text-transform: uppercase;
  background: transparent; color: var(--fg-2); border: 1px solid var(--rule-strong); padding: 0.35rem 0.7rem; cursor: pointer;
}
.filters button:hover { color: var(--fg); border-color: var(--fg-2); }
.filters button[aria-pressed="true"] { color: var(--fg); border-color: var(--red); box-shadow: inset 0 -2px 0 var(--red); }
.works { list-style: none; padding: 0; margin: 0; max-width: none; }
.work { display: grid; grid-template-columns: 7.5rem minmax(0, 1fr); column-gap: 1.6rem; padding-block: 1.35rem; }
.work:first-child { padding-top: 0; }
.work > div > * { margin: 0 0 var(--work-step); }
.work > div > :last-child { margin-bottom: 0; }
.works { --work-step: 0.5rem; }
/* The year's cap line meets the title's: title cap line 0.359rem below its box, year 0.310rem. */
.work-meta { padding-top: 0.049rem; font-family: var(--sans); font-size: 0.72rem; line-height: 1.6; color: var(--fg-2); font-variant-numeric: tabular-nums; display: flex; flex-direction: column; gap: 0.15rem; }
.work-meta .year { color: var(--fg); font-weight: 500; }
.work-meta .year:empty { display: none; }
.work-meta .type { text-transform: uppercase; letter-spacing: 0.08em; font-size: 0.64rem; }
.work-meta:has(.year:empty) { padding-top: 0.103rem; }   /* the kind, in smaller capitals, leads */
.work-title { font-size: 1.16rem; line-height: 1.3; max-width: none; }
.work-authors { font-size: 0.82rem; line-height: 1.45; color: var(--fg-2); max-width: none; }
.work-authors .me { color: var(--fg); }
.work-venue { font-size: 0.9rem; line-height: 1.45; color: var(--fg-2); max-width: none; }
.work-summary { font-size: 0.98rem; }
.work-links { display: flex; flex-wrap: wrap; gap: 0.3rem 1.1rem; font-family: var(--sans); font-size: 0.72rem; letter-spacing: 0.04em; align-items: baseline; }
.pending { color: var(--fg-2); }
.work-links details.cite[open] { flex-basis: 100%; }
details.cite summary { cursor: pointer; color: var(--fg); list-style: none; }
details.cite summary:hover { color: var(--red-bright); }
details.cite summary::-webkit-details-marker { display: none; }
details.cite[open] summary { color: var(--red-bright); }
.cite-box { flex-basis: 100%; margin-top: 0.6rem; position: relative; }
.cite-box pre, pre.code { margin: 0; padding: 0.8rem 5.5rem 0.8rem 0.9rem; background: var(--code-bg); border: 1px solid var(--rule); font-family: var(--mono); font-size: 0.7rem; line-height: 1.5; white-space: pre-wrap; word-break: break-word; color: var(--fg); }
pre.code { padding-right: 0.9rem; font-size: 0.8rem; }
.copy { position: absolute; top: 0.5rem; right: 0.5rem; font: 500 0.66rem var(--sans); letter-spacing: 0.08em; text-transform: uppercase; background: var(--bg); color: var(--fg); border: 1px solid var(--rule-strong); padding: 0.3rem 0.55rem; cursor: pointer; }
.copy:hover { border-color: var(--red); }
.legend { font-family: var(--sans); font-size: 0.7rem; color: var(--fg-2); display: flex; flex-wrap: wrap; gap: 0.4rem 1.4rem; margin: 0 0 0.8rem; max-width: none; }
.empty-note { font-family: var(--sans); font-size: 0.8rem; color: var(--fg-2); padding-top: 1rem; }

/* ---------- People (co-inquirers) ---------- */
.people { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 2rem 2.5rem; }
.people--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.6rem 2rem; }
.person { min-width: 0; }
.person-head { display: flex; gap: 1rem; align-items: center; margin: 0 0 0.9rem; }
.person-head .portrait { flex: none; width: 4.6rem; height: 4.6rem; border-radius: 50%; object-fit: cover; opacity: 0.94; display: block; transition: transform 135ms ease-out, opacity 135ms ease-out; }
.portrait-link { flex: none; display: block; border-radius: 50%; }
.portrait-link:hover .portrait, .portrait-link:focus-visible .portrait { transform: scale(1.09); opacity: 1; }
@media (prefers-reduced-motion: reduce) { .person-head .portrait { transition: none; } }
.person-id { min-width: 0; }
.person-head .role { margin-bottom: 0; }
.person h2, .person h3 { font-style: normal; margin: 0 0 0.15rem; font-size: 1.35rem; line-height: 1.25; }
.person .role { font-family: var(--sans); font-size: 0.74rem; color: var(--fg-2); margin: 0 0 0.8rem; line-height: 1.5; }
.person p { font-size: 1.02rem; }
.person p.work-links { font-size: 0.72rem; margin-bottom: 0; }
.collab { font-size: 1rem; color: var(--fg-2); margin-top: 1.8rem; }
/* A compact list of names with what was shared, for the co-inquirers section. */
.names { list-style: none; padding: 0; margin: 0; max-width: none; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.8rem 2.5rem; }
.names li { min-width: 0; font-size: 1.08rem; line-height: 1.35; }
.names .d { display: block; font-size: 0.92rem; color: var(--fg-2); }

/* ---------- Paired columns ---------- */
.pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 2.2rem 2.6rem; align-items: start; }
.pair .col { min-width: 0; }
.pair h3 { font-style: normal; font-size: 1.35rem; margin: 0 0 0.6rem; }
.pair p { font-size: 1.08rem; line-height: 1.45; }
.pair .plain { list-style: none; padding: 0; margin: 0; max-width: none; }
.pair .plain li { padding-block: 0.5rem; font-size: 1.04rem; line-height: 1.38; }
.pair .plain li:first-child { padding-top: 0; }

/* ---------- Contact ---------- */
.addresses { list-style: none; padding: 0; display: grid; gap: 0.5rem; }
.addresses li { display: grid; grid-template-columns: 9rem minmax(0, 1fr); gap: 1rem; align-items: baseline; }
.addresses .who { font-family: var(--sans); font-size: 0.74rem; color: var(--fg-2); }
.addresses .addr { font-family: var(--sans); font-size: 0.9rem; overflow-wrap: anywhere; }

/* ---------- Footer ---------- */
.foot { display: grid; grid-template-columns: var(--rail) minmax(0, 1fr); column-gap: var(--gap); padding-block: 2rem 0; font-family: var(--sans); font-size: 0.72rem; color: var(--fg-2); line-height: 1.7; }
.foot nav { grid-column: 2; display: flex; flex-wrap: wrap; gap: 0.3rem 1.4rem; margin-bottom: 0.8rem; }
.foot nav a { color: var(--fg); }
.foot .contact-line a { color: var(--fg); }
.foot nav a:hover, .foot p a:hover { color: var(--red-bright); }
.foot p { margin: 0; max-width: 42rem; grid-column: 2; }
.foot .contact-line { display: flex; flex-wrap: wrap; gap: 0.3rem 1.4rem; margin-bottom: 0.4rem; }
.foot .brand-mark { grid-column: 1; grid-row: 1; align-self: start; }

/* ---------- Review mode (#review) ---------- */
.review-bar { display: none; }
html.review [data-verify] { background: var(--mark); box-shadow: 0 0 0 2px var(--mark); cursor: help; }
html.review .review-bar {
  display: flex; gap: 1rem; align-items: baseline; flex-wrap: wrap;
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 20;
  padding: 0.7rem max(24px, env(safe-area-inset-right, 0px)) calc(0.7rem + env(safe-area-inset-bottom, 0px)) max(24px, env(safe-area-inset-left, 0px));
  background: var(--fg); color: var(--bg); font-family: var(--sans); font-size: 0.76rem;
}
.review-bar a { color: var(--bg); }

/* ---------- Narrow screens ---------- */
@media (max-width: 760px) { .pair, .names { grid-template-columns: minmax(0, 1fr); gap: 1.8rem; } .names { gap: 0.8rem; } }
@media (max-width: 1100px) {
  :root { --margin: 12rem; }
  .areas--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.4rem 1.6rem; }
  .cards, .people--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 860px) {
  .page { padding-left: max(18px, env(safe-area-inset-left, 0px)); padding-right: max(18px, env(safe-area-inset-right, 0px)); }
  .hero, .section, .foot { grid-template-columns: minmax(0, 1fr); }
  .hero > .eyebrow, .hero > :not(.eyebrow), .foot p, .foot nav, .foot .brand-mark { grid-column: 1; grid-row: auto; }
  .foot .brand-mark { margin-bottom: 0.6rem; }
  .hero { padding-block: 3.2rem 2.8rem; }
  .hero .eyebrow { margin-bottom: 1.1rem; padding-top: 0; }
  .hero > .intro { padding-top: 0; }
  .home-hero { padding-bottom: 1.5rem; }   /* 25% less space before the first section (5.2rem to 3.9rem) */
  .section { padding-block: 2.4rem var(--tail); }
  :root { --tail: 1.1rem; }
  .section > .label { position: static; padding: 0 0 1rem; }
  .body > :is(figure, .cards, .gallery, .people):first-child { margin-top: 0; }
  .body { padding-right: 0; }
  .sidenote, .marginnote { display: none; }
  label.sidenote-number { cursor: pointer; }
  /* Margin notes become toggles that open in place: numbered for sidenotes, a red plus for margin notes. */
  label.margin-toggle:not(.sidenote-number) { display: inline; cursor: pointer; }
  label.margin-toggle:not(.sidenote-number)::after {
    content: "+"; font-family: var(--sans); font-size: 0.8rem; font-weight: 500; color: var(--red-bright);
    position: relative; vertical-align: super; line-height: 0; margin-left: 0.1em;
  }
  .margin-toggle:checked + .sidenote, .margin-toggle:checked + .marginnote {
    display: block; float: none; width: auto; margin: 0.6rem 0 0.8rem; padding-left: 0.9rem; border-left: 1px solid var(--red); color: var(--fg);
  }
  .areas { grid-template-columns: minmax(0, 1fr); gap: 1.4rem; }
  .people { grid-template-columns: minmax(0, 1fr); }
  .nav { gap: 0.3rem 1.1rem; }
  .intro { grid-template-columns: 6.5rem minmax(0, 1fr); column-gap: 1.4rem; }
  .intro-photo { width: 6.5rem; height: 6.5rem; }
}
@media (max-width: 560px) {
  [id], main > .section[id], .work[id], .featured li[id], .work[id]:first-child, .featured li[id]:first-child { scroll-margin-top: 1rem; }   /* the menu bar is not pinned here */
  body { font-size: 1.08rem; }
  .masthead { position: static; }
  .areas, .cards, .people--3 { grid-template-columns: minmax(0, 1fr); }
  .work, .timeline { grid-template-columns: minmax(0, 1fr); row-gap: 0.4rem; }
  .timeline dd { margin-bottom: 0.5rem; }
  .work-meta { flex-direction: row; flex-wrap: wrap; gap: 0.2rem 1rem; align-items: center; }
  .addresses li { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .problems li { grid-template-columns: 2.2rem minmax(0, 1fr); }
  .intro { grid-template-columns: minmax(0, 1fr); row-gap: 1.2rem; }
  .intro .tagline { font-size: 1.45rem; }
}

@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { transition-duration: 0.01ms !important; } }

/* ---------- Page components (integration) ---------- */
/* A section with no label (a continuation of the one above) keeps its body in the text column. */
.section > .body { grid-column: 2; }
/* Small headings inside a section body: sans small capitals, like the rail labels. */
.list-head { font-family: var(--sans); font-size: 0.68rem; font-weight: 500; font-style: normal; letter-spacing: 0.12em; text-transform: uppercase; color: var(--fg-2); line-height: 1.5; margin: 2.6rem 0 1.1rem; }
.body > .list-head:first-child { margin-top: 0; }
.section:has(> .body > .list-head:first-child) { --label-pt: 0; }
.section:has(> .body > .lead:first-child) { --label-pt: 0.218rem; }

/* Home: strands. The title, then the model, then the essay. */
.body > h2 + figure.model { margin-top: 1.5rem; }
.body > figure.model { margin-bottom: 2rem; }
.body > figure.model + p { margin-top: 0; }
.body > .featured + .related { margin-top: 1.6rem; }
.related .exists, .profiles .exists, .contact-links .exists { font-family: var(--math); }
.featured .tag { font-family: var(--sans); font-size: 0.64rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--fg); margin-right: 0.35rem; }
.stories .yr { color: var(--fg-2); font-size: 0.95rem; }
.courses .d { font-family: var(--sans); font-size: 0.76rem; letter-spacing: 0.02em; margin-top: 0.15rem; }
.courses li { padding-block: 0.6rem; }
.names .d a { color: inherit; }
.names .d a:hover { color: var(--red-bright); }
.contact-links, .profiles { font-size: 0.8rem; }

/* Verse: one line per span, wrapped lines hang. */
.verse.poem { white-space: normal; max-width: var(--measure); }
.verse.poem p { margin: 0 0 1.1rem; max-width: none; }
.verse.poem .line { display: block; padding-left: 1.4em; text-indent: -1.4em; }
.verse.poem + .attribution { margin: 0 0 0.4rem; }
.poem-title { font-size: 1.22rem; line-height: 1.3; margin: 0 0 1.1rem; }
.poem-title .yr { color: var(--fg-2); font-size: 0.95rem; }
.verse.poem + .attribution + .list-head { margin-top: 2.6rem; }
blockquote.epigraph { padding-left: 0; }
blockquote.epigraph p { font-size: 1.24rem; line-height: 1.45; font-style: italic; margin: 0; }
.section:has(> .body > blockquote.epigraph:first-child) { --label-pt: 0.218rem; }

/* Research: talks given on several occasions. */
.occasions { list-style: none; padding: 0; margin: 0; max-width: none; font-size: 0.92rem; line-height: 1.45; color: var(--fg-2); }
.occasions li + li { margin-top: 0.2rem; }
.occasions .nw { white-space: nowrap; }
.occasions .inv { font-family: var(--sans); font-size: 0.68rem; letter-spacing: 0.04em; margin-left: 0.2rem; }
.occasions .vid { font-family: var(--sans); font-size: 0.72rem; letter-spacing: 0.04em; color: var(--fg); margin-left: 0.4rem; }
.occasions .vid:hover { color: var(--red-bright); }
.works--upcoming { margin-bottom: 0.4rem; }
.work .work-title a:hover { color: var(--red-bright); }

/* Models: thumbnails are app screenshots on white, shown whole. */
.card-thumb { object-fit: contain; background: #fff; padding: 0.4rem; }
.card-thumb-link { display: block; }
.card-thumb-link:hover .card-thumb { border-color: var(--rule-strong); }
.card-thumb--empty { display: block; background: transparent; border-style: dashed; }
/* Night: the screenshots and infographics are on white grounds; dim them so they do not outshine
   the page, and show them at full strength on hover or focus. */
:root[data-theme="dark"] :is(.card-thumb, .gallery img) { filter: brightness(0.8) contrast(1.05); transition: filter 160ms ease; }
:root[data-theme="dark"] :is(.card:hover, .card:focus-within, .gallery li:hover, .gallery li:focus-within) :is(.card-thumb, img) { filter: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) :is(.card-thumb, .gallery img) { filter: brightness(0.8) contrast(1.05); transition: filter 160ms ease; }
  :root:not([data-theme="light"]) :is(.card:hover, .card:focus-within, .gallery li:hover, .gallery li:focus-within) :is(.card-thumb, img) { filter: none; }
}
.card h3 a:hover { color: var(--red-bright); }

/* Sketchbook galleries: the panels of one infographic in a row of equal height. Each item's
   flex-grow is its image's aspect ratio (--ar, width / height, set from the file at build time),
   so the panels share one height and fill the row without gaps. One column on phones. */
.gallery.gallery--row { display: flex; align-items: flex-start; gap: 1rem; max-width: 46rem; }
.gallery--row li { flex: var(--ar, 1) 1 0%; min-width: 0; }
.gallery img { background: #fff; height: auto; }
.gallery li { min-width: 0; }
.gallery a { display: block; }
/* Wide sections: only the gallery uses the wide measure; headings and text keep the text column. */
.section--wide .body > :is(h2, p, .meta-line, .related) { max-width: var(--measure); }
.body > h2 + .meta-line { margin-top: -0.2rem; }
.body > p + .gallery, .body > .meta-line + .gallery { margin-top: 1.6rem; }
.body > .gallery + .related { margin-top: 1.4rem; }

/* Plain lists of short items. */
.plainlist { list-style: none; padding: 0; margin: 0 0 1.1rem; max-width: var(--measure); }
.plainlist li { padding-block: 0.3rem; font-size: 1.04rem; line-height: 1.4; }
.plainlist li:first-child { padding-top: 0; }
.section:has(> .body > .plainlist:first-child) { --label-pt: 0.150rem; }

.intro h1.tagline { font-weight: 400; }
.timeline--areas dt { text-transform: none; }

/* Footer: the site-wide motion control, quiet. Hidden when the system asks for reduced motion,
   since nothing moves then. */
.foot .motion-line { margin-top: 0.4rem; }
.motion-toggle { font: inherit; letter-spacing: inherit; color: var(--fg-2); background: none; border: 0; padding: 0; cursor: pointer; }
.motion-toggle:hover { color: var(--red-bright); }
@media (prefers-reduced-motion: reduce) { .foot .motion-line { display: none; } }

@media (max-width: 860px) {
  .section > .body { grid-column: 1; }
  .gallery.gallery--row { gap: 0.8rem; }
}
@media (max-width: 560px) {
  .gallery.gallery--row { flex-direction: column; gap: 1.2rem; }
  .gallery--row li { flex: none; width: 100%; }
}

/* ---------- Print: ink on white ---------- */
@media print {
  :root, :root[data-theme], :root:not([data-theme="light"]) { --bg: #fff; --fg: #000; --fg-2: #444; --rule: #ccc; --rule-strong: #888; --red: #8a1f15; --red-bright: #8a1f15; --chalk: #222; --code-bg: #f4f4f4; --grain-opacity: 0; color-scheme: light; }
  html { font-size: 10.5pt; }
  body::after, .masthead::before, .model-background, .nav, .review-bar, .copy, details.cite, .filters, .skip, .model-controls, .model .controls, .model button { display: none !important; }
  .masthead { position: static; backdrop-filter: none; background: none; }
  .page { max-width: none; padding: 0; }
  .section { padding-block: 1.2rem 0.4rem; }
  .section > .label { position: static; }
  .work, .person, figure, .block, .card { break-inside: avoid; }
  a { text-decoration: none; }
  html.review [data-verify] { background: none; box-shadow: none; }
}

/* Selected work on the home page: closed by default, opened with the + as elsewhere. */
details.selected-work { margin-top: 1.6rem; }
details.selected-work > .featured { margin-top: 0; }

/* ∃xProof AI card after the AI safety strand, after danielherrmann.ca's: a thin rule, a red left
   edge, and on hover a red border and an underlined link line. */
.xp-card { display: grid; gap: 0.45rem; margin: 2rem 0 0; padding: 1.3rem 1.5rem 1.25rem;
  border: 1px solid var(--rule); border-left: 2px solid var(--red-bright); color: var(--fg);
  text-decoration: none; transition: border-color 0.2s ease; max-width: 40rem; }
.xp-card:hover, .xp-card:focus-visible { border-color: var(--red-bright); color: var(--fg); }
.xp-card:hover .xp-go, .xp-card:focus-visible .xp-go { text-decoration: underline; text-underline-offset: 0.15em; }
.xp-mark { font-size: 1.5rem; line-height: 1.1; letter-spacing: 0.005em; }
.xp-line { font: 0.86rem/1.5 var(--sans); color: var(--fg-2); }
.xp-go { font: 0.78rem var(--sans); color: var(--red-bright); }

/* About: the talk photo under the page head. */
.about-photo { display: block; width: 100%; max-width: 26rem; height: auto; margin: 1.6rem 0 0; }

/* "How it works" as a link at the end of a model's caption; the disclosure's own summary hides. */
details.how--linked > summary { display: none; }
details.how--linked { margin-top: 0.6rem; }
figcaption .how-link { all: unset; display: inline; font: inherit; color: var(--red-bright); cursor: pointer; }
figcaption .how-link:focus-visible { outline: 2px solid var(--red-bright); outline-offset: 2px; }
figcaption .how-link:hover { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
/* KaTeX math at the size of the surrounding text. */
.katex { font-size: 1.02em; }
.katex-display { margin: 0.7rem 0; overflow-x: auto; overflow-y: hidden; }