@font-face { font-family: 'Jost'; font-style: italic; font-weight: 100; font-display: swap; src: url("/assets/fonts/jost-latin-100-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 100; font-display: swap; src: url("/assets/fonts/jost-latin-100-normal.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: italic; font-weight: 200; font-display: swap; src: url("/assets/fonts/jost-latin-200-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 200; font-display: swap; src: url("/assets/fonts/jost-latin-200-normal.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: italic; font-weight: 300; font-display: swap; src: url("/assets/fonts/jost-latin-300-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 300; font-display: swap; src: url("/assets/fonts/jost-latin-300-normal.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: italic; font-weight: 400; font-display: swap; src: url("/assets/fonts/jost-latin-400-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 400; font-display: swap; src: url("/assets/fonts/jost-latin-400-normal.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: italic; font-weight: 500; font-display: swap; src: url("/assets/fonts/jost-latin-500-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 500; font-display: swap; src: url("/assets/fonts/jost-latin-500-normal.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: italic; font-weight: 600; font-display: swap; src: url("/assets/fonts/jost-latin-600-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 600; font-display: swap; src: url("/assets/fonts/jost-latin-600-normal.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: italic; font-weight: 700; font-display: swap; src: url("/assets/fonts/jost-latin-700-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 700; font-display: swap; src: url("/assets/fonts/jost-latin-700-normal.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: italic; font-weight: 800; font-display: swap; src: url("/assets/fonts/jost-latin-800-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 800; font-display: swap; src: url("/assets/fonts/jost-latin-800-normal.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: italic; font-weight: 900; font-display: swap; src: url("/assets/fonts/jost-latin-900-italic.woff2") format("woff2"); }
@font-face { font-family: 'Jost'; font-style: normal; font-weight: 900; font-display: swap; src: url("/assets/fonts/jost-latin-900-normal.woff2") format("woff2"); }
@font-face { font-family: 'DM Mono'; font-style: italic; font-weight: 300; font-display: swap; src: url("/assets/fonts/dm-mono-latin-300-italic.woff2") format("woff2"); }
@font-face { font-family: 'DM Mono'; font-style: normal; font-weight: 300; font-display: swap; src: url("/assets/fonts/dm-mono-latin-300-normal.woff2") format("woff2"); }
@font-face { font-family: 'DM Mono'; font-style: italic; font-weight: 400; font-display: swap; src: url("/assets/fonts/dm-mono-latin-400-italic.woff2") format("woff2"); }
@font-face { font-family: 'DM Mono'; font-style: normal; font-weight: 400; font-display: swap; src: url("/assets/fonts/dm-mono-latin-400-normal.woff2") format("woff2"); }
@font-face { font-family: 'DM Mono'; font-style: italic; font-weight: 500; font-display: swap; src: url("/assets/fonts/dm-mono-latin-500-italic.woff2") format("woff2"); }
@font-face { font-family: 'DM Mono'; font-style: normal; font-weight: 500; font-display: swap; src: url("/assets/fonts/dm-mono-latin-500-normal.woff2") format("woff2"); }
:root {
  --bg-light-base: #ffffff;
  --fg-light-base-body: #33444f;
  --fg-light-base-heading: #1c2a35;
  --fg-light-base-muted: #4d5e69;
  --fg-light-base-link: #0b6a5c;
  --fg-light-base-inverse: #1c2a35;
  --bg-light-card: #e8f4ef;
  --fg-light-card-body: #33444f;
  --fg-light-card-heading: #1c2a35;
  --fg-light-card-muted: #4d5e69;
  --fg-light-card-link: #0b6a5c;
  --fg-light-card-inverse: #1c2a35;
  --bg-light-elevated: #f4faf7;
  --fg-light-elevated-body: #33444f;
  --fg-light-elevated-heading: #1c2a35;
  --fg-light-elevated-muted: #4d5e69;
  --fg-light-elevated-link: #0b6a5c;
  --fg-light-elevated-inverse: #1c2a35;
  --brand-light-accent: #0b6a5c;
  --brand-light-accent-hover: #07483e;
  --brand-light-on-accent: #ffffff;
  --focus-light-ring: #0b6a5c;
  --border-light-default: #6b8390;
  --border-light-subtle: #cfe5dc;
}
.bg-surface-base { background: var(--bg-light-base); --fg-body: var(--fg-light-base-body); --fg-heading: var(--fg-light-base-heading); --fg-muted: var(--fg-light-base-muted); --fg-link: var(--fg-light-base-link); --fg-inverse: var(--fg-light-base-inverse); }
.bg-surface-card { background: var(--bg-light-card); --fg-body: var(--fg-light-card-body); --fg-heading: var(--fg-light-card-heading); --fg-muted: var(--fg-light-card-muted); --fg-link: var(--fg-light-card-link); --fg-inverse: var(--fg-light-card-inverse); }
.bg-surface-elevated { background: var(--bg-light-elevated); --fg-body: var(--fg-light-elevated-body); --fg-heading: var(--fg-light-elevated-heading); --fg-muted: var(--fg-light-elevated-muted); --fg-link: var(--fg-light-elevated-link); --fg-inverse: var(--fg-light-elevated-inverse); }
.text-role-body { color: var(--fg-body); overflow-wrap: anywhere; }
.text-role-heading { color: var(--fg-heading); overflow-wrap: anywhere; }
.text-role-muted { color: var(--fg-muted); }
.text-role-link { color: var(--fg-link); }
.text-role-inverse { color: var(--fg-inverse); }
.text-role-link { text-decoration: underline; }
.text-role-link:hover { color: var(--brand-light-accent-hover); }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 2px solid var(--focus-light-ring); outline-offset: 2px; }
img { max-width: 100%; height: auto; }
.site-logo { max-width: 100%; height: auto; }
.site-menu > summary { list-style: none; cursor: pointer; }
.site-menu > summary::-webkit-details-marker { display: none; }
:where(section[data-section][style]) { background-size: cover; background-position: center; padding: clamp(1.5rem, 4vw, 3rem); }
.skip-link { position: absolute; left: -9999px; }
.skip-link:focus { position: static; padding: 0.25rem 0.5rem; outline: 2px solid var(--focus-light-ring); }

/* Light-science notebook: white paper, pale mint panels, slate ink, ruled grid. */

:root {
  --paper: var(--bg-light-base);
  --mint: var(--bg-light-card);
  --mint-pale: var(--bg-light-elevated);
  --ink: var(--fg-light-base-heading);
  --rule: var(--border-light-default);
  --grid: var(--border-light-subtle);
  --accent: var(--brand-light-accent);
  --accent-deep: var(--brand-light-accent-hover);
  --on-accent: var(--brand-light-on-accent);
  --sans: 'Jost', 'Futura', 'Century Gothic', system-ui, sans-serif;
  --mono: 'DM Mono', ui-monospace, 'SFMono-Regular', Menlo, monospace;
  --cell: 1.75rem;
  --measure: 38rem;
  --wide: 74rem;
  --gutter: clamp(1rem, 4vw, 2.5rem);
}

*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 1.125rem;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3 { margin: 0; text-wrap: balance; }
p, ul, ol, figure { margin: 0; }

a.text-role-link { text-underline-offset: 0.2em; text-decoration-thickness: 1px; }
a.text-role-link:hover { text-decoration-thickness: 2px; }

.skip-link:focus { position: absolute; left: 1rem; top: 1rem; z-index: 30; background: var(--paper); }

/* ---------- grid paper (pseudo layer, never on a text carrier) ---------- */

.spread, .hub-panel {
  position: relative;
  isolation: isolate;
}

.spread::before, .hub-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(to right, var(--grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px);
  background-size: var(--cell) var(--cell);
  opacity: 0.55;
}

/* ---------- chrome ---------- */

.nb-header { border-bottom: 1px solid var(--rule); position: relative; z-index: 10; }

.nb-bar {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0.75rem var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.nb-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  min-height: 44px;
  text-decoration: none;
}

.nb-brand .site-logo { width: 2.4rem; height: 2.4rem; flex: none; }

.nb-brand-name {
  font-weight: 500;
  font-size: 1.15rem;
  line-height: 1.15;
  letter-spacing: 0.01em;
  max-width: 16rem;
}

/* Desktop: one header row, brand left, notebook tab bar right. */
.nb-tabs { display: none; }
.site-nav ul {
  display: flex;
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 1px solid var(--rule);
}
.site-nav li { border-right: 1px solid var(--rule); }
.site-nav a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 1.15rem;
  font-family: var(--mono);
  font-size: 0.95rem;
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
}
.site-nav a:hover { background: var(--mint); border-bottom-color: var(--ink); }
.site-nav a:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }

@media (min-width: 60rem) {
  .nb-tabs { display: block; }
  .nb-nav { display: none; }
}

/* Phone: the toggle opens a full-width index sheet under the header. */
.nb-nav { flex: none; white-space: nowrap; }

.site-menu > summary {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  min-height: 44px;
  padding: 0 0.9rem;
  border: 1px solid var(--ink);
  border-radius: 3px;
  font-family: var(--mono);
  font-size: 0.95rem;
  background: var(--paper);
  cursor: pointer;
}

.site-menu .menu-icon {
  width: 1rem;
  height: 0.7rem;
  border-top: 1px solid currentColor;
  border-bottom: 1px solid currentColor;
  position: relative;
}

.site-menu .menu-icon::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  border-top: 1px solid currentColor;
}

.site-menu[open] > summary { background: var(--mint); }

.site-menu > ul {
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  margin: 0;
  padding: 0.5rem var(--gutter) 1.5rem;
  list-style: none;
  counter-reset: sheet;
  background: var(--paper);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--ink);
  white-space: normal;
  box-shadow: 0 6px 0 var(--mint);
  isolation: isolate;
}
.site-menu > ul::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(to right, var(--grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px);
  background-size: var(--cell) var(--cell);
  opacity: 0.55;
}

.site-menu > ul li {
  counter-increment: sheet;
  display: grid;
  grid-template-columns: 3.25rem minmax(0, 1fr);
  align-items: baseline;
  border-bottom: 1px solid var(--rule);
}
.site-menu > ul li::before {
  content: "p. " counter(sheet, decimal-leading-zero);
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink);
}

.site-menu > ul a {
  display: flex;
  align-items: center;
  min-height: 52px;
  padding: 0.5rem 0;
  font-size: 1.35rem;
  font-weight: 500;
  line-height: 1.2;
}

.site-menu > ul a:hover { text-decoration-thickness: 2px; }

.nb-page { flex: 1 0 auto; padding-bottom: 4.5rem; }
.nb-page:has(> .nb-home) { padding-bottom: 0; }

.breadcrumbs {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 1.1rem var(--gutter) 0;
  font-family: var(--mono);
  font-size: 0.85rem;
}
.breadcrumbs ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0.2rem 0.5rem; }
.breadcrumbs li + li::before { content: "/"; margin-right: 0.5rem; color: var(--rule); }

.nb-footer { border-top: 1px solid var(--rule); }

.nb-footer-inner {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 2.25rem var(--gutter) 2.5rem;
  display: grid;
  gap: 0.75rem;
  font-size: 1rem;
}

.nb-footer-line { font-size: 1.2rem; font-weight: 500; max-width: 34rem; line-height: 1.4; }
.nb-footer-links { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0 1.5rem; }
.nb-footer-links a { display: inline-flex; align-items: center; min-height: 44px; }
.nb-footer-client:empty { display: none; }
.nb-footer-name { font-family: var(--mono); font-size: 0.85rem; }

/* ---------- shared body typography ---------- */

main h1 { font-family: var(--sans); font-weight: 500; line-height: 1.1; letter-spacing: -0.01em; }
main h2 { font-family: var(--mono); font-weight: 500; font-size: 1.15rem; line-height: 1.35; letter-spacing: -0.01em; }
main h3 { font-family: var(--mono); font-weight: 400; font-size: 1rem; line-height: 1.4; }
main p, main li { max-width: var(--measure); }
main ul, main ol { padding-left: 1.2rem; }
main li + li { margin-top: 0.35rem; }
main * + p, main * + ul, main * + ol { margin-top: 0.9rem; }
main * + h2 { margin-top: 2.4rem; }
main * + h3 { margin-top: 1.6rem; }
main strong { font-weight: 600; }

.photo-hero, .photo-inline { margin: 0 0 1.75rem; }
.photo-inline { margin-top: 1.75rem; }
.photo-hero img, .photo-inline img {
  display: block;
  width: 100%;
  border: 1px solid var(--rule);
  padding: 0.4rem;
  background: var(--paper);
}

section[data-section][style] {
  margin: 2rem 0;
  padding: clamp(1.5rem, 5vw, 3.5rem) clamp(0.75rem, 4vw, 2.5rem);
  background-size: cover;
  background-position: center;
}
section[data-section][style] > .bg-surface-card {
  padding: clamp(1.25rem, 3vw, 2rem);
  border: 1px solid var(--rule);
  max-width: 40rem;
}

.accent-block {
  margin: 1.5rem 0 0;
  padding: 0.75rem 1rem;
  border-left: 3px solid var(--accent);
  background: var(--mint-pale);
}

.table-scroll { overflow-x: auto; margin-top: 1.25rem; }
.table-scroll table { border-collapse: collapse; font-size: 1rem; }
.table-scroll th, .table-scroll td { border: 1px solid var(--rule); padding: 0.5rem 0.75rem; text-align: left; vertical-align: top; }
.table-scroll th { font-family: var(--mono); font-weight: 500; background: var(--mint); }

/* ---------- home: notebook spread ---------- */

.spread { border-bottom: 1px solid var(--rule); }

.spread-inner {
  max-width: var(--wide);
  margin: 0 auto;
  padding: clamp(1.75rem, 5vw, 3.5rem) var(--gutter) clamp(2rem, 5vw, 3rem);
}

.spread-text {
  margin-top: clamp(2rem, 5vw, 3.25rem);
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  column-gap: clamp(2rem, 5vw, 4.5rem);
  align-items: end;
}
.spread-folio { grid-column: 1 / -1; }
.spread-headline { grid-column: 1; grid-row: 2 / span 3; align-self: end; }
.spread-text > .spread-line, .spread-text > .spread-note { grid-column: 2; }

.spread-folio h1 {
  font-family: var(--mono);
  font-weight: 400;
  font-size: 0.95rem;
  letter-spacing: 0;
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border: 1px solid var(--rule);
  background: var(--paper);
}

.spread-headline {
  margin-top: 1rem;
  font-size: clamp(2.3rem, 5.5vw, 4.25rem);
  font-weight: 500;
  line-height: 1.02;
  letter-spacing: -0.025em;
  max-width: 16ch;
  text-wrap: balance;
}

.spread-line { font-size: 1.15rem; max-width: 30rem; }
.spread-note {
  margin-top: 1.25rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 0.85rem;
  max-width: 30rem;
}

.spectrum { padding: 0; }

.spectrum-strip { display: block; width: 100%; height: clamp(4rem, 9vw, 7rem); }

.spectrum-scale {
  position: relative;
  height: 1.4rem;
  margin-top: 0.3rem;
  font-family: var(--mono);
  font-size: 0.8rem;
}
.spectrum-tick { position: absolute; top: 0; white-space: nowrap; }
.tick-400 { left: 0; }
.tick-700 { left: 42.857%; transform: translateX(-50%); }
.tick-1100 { right: 0; }

.spectrum-bands {
  display: grid;
  grid-template-columns: 3fr 4fr;
  margin-top: 0.5rem;
}
.spectrum-band {
  position: relative;
  padding: 0.9rem 0.5rem 0 0;
  font-size: 0.95rem;
  font-weight: 500;
  line-height: 1.3;
}
.spectrum-band::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 1px;
  height: 0.65rem;
  background: var(--ink);
}
.band-nir { padding-left: 0.6rem; }
.band-nir::before { left: 0.6rem; }

.spectrum-caption {
  margin-top: 0.75rem;
  font-family: var(--mono);
  font-size: 0.8rem;
}

.contents-list {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 var(--gutter) clamp(2.5rem, 6vw, 4rem);
}

.contents-row {
  display: grid;
  grid-template-columns: 5rem minmax(0, 1.1fr) minmax(0, 1fr);
  gap: 0.4rem 2rem;
  align-items: baseline;
  padding: 1.1rem 0.5rem;
  border-top: 1px solid var(--rule);
  text-decoration: none;
}
.contents-row:last-child { border-bottom: 1px solid var(--ink); }
.contents-list .contents-row:first-child { border-top: 1px solid var(--ink); }
.contents-row:hover .row-title { text-decoration: underline; text-underline-offset: 0.2em; text-decoration-thickness: 1px; }
.contents-row:hover { box-shadow: inset 3px 0 0 var(--accent); }
.contents-row:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.row-folio { font-family: var(--mono); font-size: 0.85rem; }
.row-title { font-size: 1.35rem; font-weight: 500; line-height: 1.2; }
.row-text { font-size: 1rem; line-height: 1.5; }

.home-notes-inner {
  max-width: var(--wide);
  margin: 0 auto;
  padding: clamp(2.5rem, 6vw, 4.5rem) var(--gutter) clamp(3rem, 7vw, 5rem);
}

.home-notes .reading { max-width: 46rem; }
.home-notes .reading h2 {
  padding-top: 0.6rem;
  border-top: 1px solid var(--rule);
}

/* ---------- topic hub: contents + diagram panel ---------- */

.hub-head, .article-head, .about-head, .contact-head {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 1.75rem var(--gutter) 0;
}

.hub-title h1, .article-title h1, .about-title h1, .contact-title h1, .thanks-title h1 {
  font-size: clamp(2rem, 4.5vw, 3rem);
  max-width: 22ch;
}

.hub-grid {
  max-width: var(--wide);
  margin: 2rem auto 0;
  padding: 0 var(--gutter);
  display: grid;
  grid-template-columns: minmax(14rem, 19rem) minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3.5rem);
  align-items: start;
}

.hub-contents {
  position: sticky;
  top: 1rem;
  border-top: 1px solid var(--ink);
  padding-top: 0.75rem;
}

.hub-contents-label { font-family: var(--mono); font-size: 0.85rem; }

.hub-items ul {
  list-style: none;
  margin: 0.5rem 0 0;
  padding: 0;
  counter-reset: contents;
  font-family: var(--mono);
  font-size: 0.9rem;
  line-height: 1.45;
}
.hub-items li {
  counter-increment: contents;
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  border-bottom: 1px solid var(--grid);
}
.hub-items li + li { margin-top: 0; }
.hub-items li::before {
  content: counter(contents, decimal-leading-zero);
  padding: 0.65rem 0;
  color: var(--rule);
}
.hub-items a { display: block; padding: 0.65rem 0; min-height: 44px; }

.hub-panel {
  border: 1px solid var(--ink);
  padding: clamp(1.25rem, 4vw, 2.75rem);
}

.hub-panel::after {
  content: "";
  position: absolute;
  top: -6px;
  right: -6px;
  width: 12px;
  height: 12px;
  border-top: 1px solid var(--ink);
  border-right: 1px solid var(--ink);
}

.hub-body h2 {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}
.hub-body h2::after {
  content: "";
  flex: 1;
  border-top: 1px dashed var(--rule);
  transform: translateY(-0.3em);
}
.hub-body ul { padding-left: 0; list-style: none; }
.hub-body li {
  padding: 0.6rem 0 0.6rem 1rem;
  border-left: 2px solid var(--accent);
  background: var(--mint-pale);
  padding-right: 0.75rem;
}

/* ---------- article: annotated reading column ---------- */

.article-body {
  max-width: var(--wide);
  margin: 2rem auto 0;
  padding: 0 var(--gutter);
  counter-reset: step;
}

.article-body > * { max-width: var(--measure); }

.article-body h2 {
  counter-increment: step;
  margin-top: 2.6rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--rule);
  display: grid;
  grid-template-columns: 3rem minmax(0, 1fr);
  align-items: baseline;
}
.article-body h2::before {
  content: counter(step, decimal-leading-zero);
  font-size: 0.85rem;
  color: var(--rule);
}
section[data-section][style] .bg-surface-card h2 { margin-top: 0; padding-top: 0; border-top: 0; }

.article-body > h3, .article-body > h3 + p { padding-left: 3rem; }

@media (min-width: 64rem) {
  .article-body { padding-left: calc(var(--gutter) + 14rem); }
  .article-body > h2 {
    float: left;
    clear: both;
    width: 12rem;
    margin-left: -14rem;
    font-size: 1rem;
    display: block;
  }
  .article-body > h2::before { display: block; margin-bottom: 0.25rem; }
  .article-body > h2 + * {
    margin-top: 2.6rem;
    padding-top: 0.9rem;
    border-top: 1px solid var(--rule);
  }
  .article-body > h3, .article-body > h3 + p { padding-left: 0; }
  .article-body > .photo-hero,
  .article-body > section[data-section][style] { clear: both; }
}

/* ---------- about: field notes ---------- */

.about-sheet {
  max-width: var(--wide);
  margin: 1.5rem auto 0;
  padding: 0 var(--gutter);
  counter-reset: note;
}
.about-sheet > * { max-width: var(--measure); }
.about-sheet > .photo-hero { margin: 0 0 1.5rem; }
.about-sheet > .photo-hero img {
  aspect-ratio: 5 / 2;
  object-fit: cover;
  height: auto;
}
.about-sheet h2 {
  counter-increment: note;
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  padding: 0.4rem 0.7rem;
  background: var(--mint);
  border-left: 3px solid var(--ink);
}
.about-sheet h2::before {
  content: "n." counter(note);
  font-size: 0.8rem;
  color: var(--ink);
}
.about-sheet h2 + p, .about-sheet h2 + ul { margin-top: 0.75rem; }

@media (min-width: 56rem) {
  .about-head { padding-bottom: 1.25rem; border-bottom: 1px solid var(--ink); }
  .about-sheet {
    display: grid;
    grid-template-columns: minmax(0, var(--measure)) minmax(14rem, 20rem);
    column-gap: clamp(2rem, 5vw, 4.5rem);
    align-items: start;
  }
  .about-sheet > * { grid-column: 1; }
  .about-sheet > .photo-hero {
    grid-column: 2;
    grid-row: 1 / span 40;
    position: sticky;
    top: 1.5rem;
    margin: 0;
    transform: rotate(1.25deg);
    box-shadow: 5px 5px 0 var(--mint);
  }
  .about-sheet > .photo-hero img { aspect-ratio: 3 / 4; }
  .about-sheet > h2:first-of-type { margin-top: 0; }
}

.about-sheet ul {
  list-style: none;
  padding: 1rem 1.25rem;
  border: 1px solid var(--rule);
  background: var(--mint-pale);
}
.about-sheet li {
  font-family: var(--mono);
  font-size: 0.95rem;
  padding-left: 1.5rem;
  position: relative;
}
.about-sheet li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.45em;
  width: 0.7rem;
  height: 0.7rem;
  border: 1px solid var(--accent);
}

/* ---------- contact: specimen card ---------- */

.contact-grid {
  max-width: var(--wide);
  margin: 2rem auto 0;
  padding: 0 var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 26rem);
  gap: clamp(1.5rem, 5vw, 4rem);
  align-items: start;
}

.specimen { display: grid; gap: 1rem; }

.specimen-card {
  border: 1px solid var(--ink);
  box-shadow: 6px 6px 0 var(--mint);
}

.specimen-strip {
  padding: 0.75rem 1.1rem;
  border-bottom: 1px solid var(--ink);
}
.specimen-strip-text { font-family: var(--mono); font-size: 0.9rem; }

.specimen-fields { padding: 1.1rem; display: grid; gap: 1rem; }

.specimen-field { display: grid; gap: 0.3rem; }
.specimen-field label { font-family: var(--mono); font-size: 0.85rem; }

.specimen-field input {
  font: inherit;
  font-size: 1rem;
  min-height: 44px;
  padding: 0.5rem 0.65rem;
  border: 0;
  border-bottom: 1px solid var(--rule);
  border-radius: 0;
  background: var(--paper);
  color: var(--ink);
}
.specimen-field input:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; border-bottom-color: var(--accent); }

.specimen-submit {
  justify-self: start;
  font-family: var(--mono);
  font-size: 0.95rem;
  min-height: 44px;
  padding: 0 1.25rem;
  border: 1px solid var(--accent);
  border-radius: 3px;
  background: var(--accent);
  color: var(--on-accent);
  cursor: pointer;
}
.specimen-submit:hover { background: var(--accent-deep); border-color: var(--accent-deep); }

.locality {
  padding: 0.9rem 1.1rem;
  border: 1px solid var(--rule);
}
.locality-label { font-family: var(--mono); font-size: 0.85rem; }
.locality-text { margin-top: 0.25rem; font-size: 1rem; }

.contact-body h2 { padding-top: 0.6rem; border-top: 1px solid var(--rule); }

/* ---------- thank you / not found ---------- */

.thanks-sheet {
  max-width: 44rem;
  margin: clamp(2rem, 6vw, 4rem) auto 0;
  padding: clamp(1.5rem, 4vw, 2.5rem) var(--gutter);
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--rule);
}
.thanks-stamp {
  margin-top: 0.9rem;
  font-family: var(--mono);
  font-size: 0.9rem;
  display: inline-block;
  padding: 0.2rem 0.55rem;
  border: 1px dashed var(--rule);
}
.thanks-body { margin-top: 1.5rem; }
.thanks-next { margin-top: 1.75rem; }
.thanks-next a { display: inline-flex; align-items: center; min-height: 44px; }

/* ---------- responsive ---------- */

@media (max-width: 56rem) {
  .hub-grid, .contact-grid { grid-template-columns: minmax(0, 1fr); }
  .spread-text { grid-template-columns: minmax(0, 1fr); }
  .spread-headline, .spread-text > .spread-line, .spread-text > .spread-note { grid-column: 1; grid-row: auto; }
  .spread-text > .spread-line { margin-top: 1rem; }
  .contents-row { grid-template-columns: minmax(0, 1fr); padding: 1rem 0; }
  .hub-contents { position: static; }
}



/* ---------- thank you: ticked notebook log ---------- */

.log-sheet {
  max-width: var(--wide);
  margin: clamp(1.5rem, 5vw, 3rem) auto 0;
  padding: 0 var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.5rem;
}

.log-entry {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--ink);
}
.log-tick { flex: none; width: 2.5rem; height: 2.5rem; }
.log-title h1 { font-size: clamp(2rem, 4.5vw, 3rem); }

.log-table {
  margin: 0;
  border: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 0.95rem;
}
.log-row {
  display: grid;
  grid-template-columns: 9rem minmax(0, 1fr);
  gap: 1rem;
  padding: 0.65rem 1rem;
}
.log-row + .log-row { border-top: 1px dashed var(--rule); }
.log-row dd { margin: 0; }

.log-body > * { max-width: var(--measure); }
.log-next a { display: inline-flex; align-items: center; min-height: 44px; }

@media (min-width: 56rem) {
  .log-sheet {
    grid-template-columns: minmax(16rem, 20rem) minmax(0, 1fr);
    column-gap: clamp(2rem, 5vw, 4.5rem);
    align-items: start;
  }
  .log-entry { grid-column: 1 / -1; }
  .log-table { grid-column: 1; grid-row: 2 / span 2; }
  .log-row { grid-template-columns: minmax(0, 1fr); gap: 0.15rem; }
  .log-body { grid-column: 1 / -1; }
  .log-next { grid-column: 1 / -1; margin-top: 0; }
}