:root {
  /* Palette — unchanged from the previous design. */
  --bg: #fbfaf8;
  --surface: #ffffff;
  --ink: #1c1b19;
  --ink-soft: #55524d;
  --line: #e6e2db;
  --accent: #9a3412;
  --accent-soft: #fef2ec;
  --teaching-bg: #f4f6f4;
  --teaching-line: #cdd8cd;
  --aside-ink: #6b6862;
  --wrap: 60rem;
  --sans:
    "Helvetica Neue", "Helvetica", "Arial", "Inter", system-ui, -apple-system,
    "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #171614;
    --surface: #201f1c;
    --ink: #ece9e3;
    --ink-soft: #a8a49c;
    --line: #33312d;
    --accent: #f0966b;
    --accent-soft: #2a211b;
    --teaching-bg: #1c211c;
    --teaching-line: #35433a;
    --aside-ink: #9a968e;
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.45;
  font-feature-settings: "kern" 1;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: 1.5rem;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
  text-underline-offset: 2px;
}

p {
  margin: 0 0 1rem;
}

.skip-link {
  position: absolute;
  left: -999px;
}
.skip-link:focus {
  left: 1rem;
  top: 1rem;
  background: var(--surface);
  padding: 0.5rem 0.75rem;
  z-index: 10;
}

/* Small uppercase label — the recurring Swiss typographic mark. */
.label-type {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.09em;
}

/* ---- Masthead ---- */
.site-header {
  border-bottom: 3px solid var(--ink);
  padding-block: 1.75rem;
}
.site-header .wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 2rem;
}
.site-title {
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-transform: uppercase;
  color: var(--ink);
}
.site-title:hover {
  text-decoration: none;
  color: var(--accent);
}
.site-tagline {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

main {
  padding-top: 3rem;
}

/* ---- Footer ---- */
.site-footer {
  margin-top: 4rem;
  border-top: 3px solid var(--ink);
  padding-block: 1.5rem 3rem;
  color: var(--ink-soft);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.site-footer p {
  margin: 0.35rem 0;
}

/* ---- Landing lede ---- */
.lede {
  margin-bottom: 2rem;
}
.lede p {
  max-width: 44em;
  font-size: 1.2rem;
  line-height: 1.4;
}
.lede .count {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

/* ---- Section jump index ---- */
.section-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.5rem;
  border-block: 1px solid var(--ink);
  padding-block: 0.7rem;
  margin: 1.5rem 0 3rem;
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.section-jump a {
  color: var(--ink);
  display: inline-flex;
  gap: 0.45rem;
  align-items: baseline;
}
.section-jump a:hover {
  color: var(--accent);
  text-decoration: none;
}
.section-jump .num {
  color: var(--accent);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

/* ---- Table of contents grid ---- */
.toc-section {
  display: grid;
  grid-template-columns: 4.5rem 1fr;
  column-gap: 2rem;
  border-top: 2px solid var(--ink);
  padding: 1rem 0 2.5rem;
}
.toc-num {
  font-size: 2.75rem;
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--accent);
  font-variant-numeric: tabular-nums lining-nums;
}
.toc-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.5rem;
}
.toc-head h2 {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.01em;
  line-height: 1.15;
}
.toc-count {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
  white-space: nowrap;
}
.toc-subtitle {
  margin: 0.5rem 0 0;
  color: var(--ink-soft);
  font-size: 0.9rem;
}
.toc-list {
  counter-reset: item;
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  columns: 2;
  column-gap: 2.5rem;
}
@media (max-width: 40rem) {
  .toc-list {
    columns: 1;
  }
}
.toc-list li {
  break-inside: avoid;
  border-top: 1px solid var(--line);
}
.toc-list a {
  display: flex;
  gap: 0.6rem;
  align-items: baseline;
  color: var(--ink);
  padding: 0.4rem 0;
  font-size: 0.92rem;
}
.toc-list a::before {
  counter-increment: item;
  content: counter(item, decimal-leading-zero);
  color: var(--ink-soft);
  font-variant-numeric: tabular-nums;
  font-size: 0.72rem;
  font-weight: 700;
  flex: none;
}
.toc-list a:hover {
  color: var(--accent);
  text-decoration: none;
}

/* ---- Concept page ---- */
.breadcrumb {
  font-size: 0.74rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.75rem;
  margin-bottom: 2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  align-items: baseline;
}
.breadcrumb a {
  color: var(--ink-soft);
}
.breadcrumb a:hover {
  color: var(--accent);
}

.concept-eyebrow {
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.75rem;
}
.concept h1 {
  margin: 0 0 2.5rem;
  font-size: clamp(2.1rem, 6vw, 3.25rem);
  font-weight: 700;
  line-height: 1.02;
  letter-spacing: -0.02em;
  max-width: 18ch;
}

.fields {
  margin: 0;
  border-bottom: 2px solid var(--ink);
}
.field {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: 0.5rem 2rem;
  border-top: 1px solid var(--line);
  padding: 1.1rem 0;
}
.field:first-child {
  border-top: 2px solid var(--ink);
}
.field dt {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-soft);
  padding-top: 0.15rem;
}
.field dd {
  margin: 0;
  max-width: 40em;
  font-size: 1.05rem;
  line-height: 1.5;
}
/* Fields now render block markdown, so tidy the paragraph spacing. */
.field dd > :first-child {
  margin-top: 0;
}
.field dd > :last-child {
  margin-bottom: 0;
}
.field dd p {
  margin: 0 0 0.75rem;
}
/* Teaching note: signalled by an accent rule + accent label, no box. */
.field-teaching {
  border-top: 2px solid var(--accent);
}
.field-teaching dt {
  color: var(--accent);
}
.field-aside dd {
  color: var(--aside-ink);
  font-size: 0.95rem;
}

@media (max-width: 34rem) {
  .field {
    grid-template-columns: 1fr;
    gap: 0.35rem;
  }
}

/* ---- Prev / next ---- */
.concept-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 3px solid var(--ink);
}
.concept-nav a {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  color: var(--ink);
}
.concept-nav a:hover {
  text-decoration: none;
}
.concept-nav a:hover .label {
  color: var(--accent);
}
.concept-nav .next {
  text-align: right;
  grid-column: 2;
  align-items: flex-end;
}
.concept-nav .dir {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
}
.concept-nav .label {
  font-weight: 500;
}

@media (max-width: 34rem) {
  .toc-section {
    grid-template-columns: 1fr;
    row-gap: 0.75rem;
  }
}

/* ---- 404 ---- */
.notfound {
  padding: 1rem 0 2rem;
}
.notfound .code {
  font-size: clamp(4rem, 18vw, 9rem);
  font-weight: 700;
  line-height: 0.85;
  letter-spacing: -0.03em;
  color: var(--accent);
  font-variant-numeric: tabular-nums lining-nums;
  margin: 0;
}
.notfound h1 {
  margin: 1rem 0 1.5rem;
  font-size: clamp(1.6rem, 5vw, 2.5rem);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: -0.01em;
}
.notfound .actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.5rem;
  border-top: 1px solid var(--ink);
  margin-top: 2rem;
  padding-top: 0.9rem;
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.notfound .actions a {
  color: var(--ink);
}
.notfound .actions a:hover {
  color: var(--accent);
  text-decoration: none;
}

/* ---- License page ---- */
.concept > p {
  font-size: 1.05rem;
  line-height: 1.5;
}
.license-statement {
  font-size: 1.2rem !important;
  line-height: 1.4;
  margin-bottom: 2rem;
}
.license-links {
  max-width: 44em;
  margin: 0 0 1.5rem;
  padding-left: 0;
  list-style: none;
}
.license-links li {
  border-top: 1px solid var(--line);
  padding: 0.6rem 0;
  font-size: 0.95rem;
}
.concept code {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.85em;
  background: var(--accent-soft);
  padding: 0.1em 0.35em;
}

/* ---- Contributors page ---- */
.contributors {
  list-style: none;
  margin: 0 0 2rem;
  padding: 0;
  border-bottom: 2px solid var(--ink);
}
.contributor {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  column-gap: 2rem;
  border-top: 1px solid var(--line);
  padding: 1.1rem 0;
}
.contributor:first-child {
  border-top: 2px solid var(--ink);
}
.contributor-name {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.contributor-name a {
  color: var(--ink);
}
.contributor-name a:hover {
  color: var(--accent);
}
.contributor-role {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
  text-align: right;
  white-space: nowrap;
}
.contributor-note {
  grid-column: 1 / -1;
  margin: 0.4rem 0 0;
  max-width: 44em;
  color: var(--ink-soft);
  font-size: 0.95rem;
  line-height: 1.5;
}
@media (max-width: 34rem) {
  .contributor {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }
  .contributor-role {
    text-align: left;
  }
}

/* ---- Media: images, gifs, video, embeds (any number, anywhere) ---- */
.concept img,
.concept video,
.concept iframe {
  max-width: 100%;
}
.concept img,
.concept video {
  height: auto;
  display: block;
}

/* Free-form body region beneath the structured fields. */
.concept-body {
  max-width: 44em;
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 2px solid var(--ink);
  font-size: 1.05rem;
  line-height: 1.5;
}
.concept-body > :first-child {
  margin-top: 0;
}
.concept-body > :last-child {
  margin-bottom: 0;
}

/* Figure with caption (from the {% figure %} / {% video %} shortcodes, or
   plain markdown images). */
figure.media {
  margin: 1.5rem 0;
}
figure.media img,
figure.media video {
  width: 100%;
  height: auto;
  display: block;
  background: var(--surface);
  border: 1px solid var(--line);
}
figure.media figcaption {
  font-size: 0.74rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  border-top: 1px solid var(--line);
  padding-top: 0.5rem;
  margin-top: 0.5rem;
}

/* A markdown image on its own line gets the same treatment. */
.concept p > img:only-child {
  border: 1px solid var(--line);
  margin: 0.5rem 0;
}

/* Responsive 16:9 wrapper for embeds ({% youtube %}, {% vimeo %}, {% embed %}). */
.embed {
  position: relative;
  aspect-ratio: 16 / 9;
  margin: 1.5rem 0;
  background: var(--surface);
  border: 1px solid var(--line);
}
.embed iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* A raw <iframe> pasted directly into a field/body (no wrapper) stays sane. */
.field dd > iframe,
.concept-body > iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
}