/* Engineering pad: green quadrille paper, ink, and a red-and-blue pencil. */
:root {
  color-scheme: light;
  --paper: #e6efe8;
  --square: #d8e5dc;
  --rule: #b9cdc1;
  --ink: #12302c;
  --ink-soft: #3f5b55;
  --blue: #2e55c9;
  --blue-text: #1f3fa6;
  --red: #b3261e;
  --sheet: 1200px;
  --margin: 190px;
  --gutter: 40px;
  --square-size: 24px;
  --display: "Hepta Slab", Rockwell, Georgia, serif;
  --body: "Atkinson Hyperlegible Next", "Atkinson Hyperlegible", Verdana, sans-serif;
}

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

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

body {
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--square) 1px, transparent 1px),
    linear-gradient(90deg, var(--square) 1px, transparent 1px);
  background-size: var(--square-size) var(--square-size);
  font: 400 1.0625rem/1.55 var(--body);
  font-variant-numeric: tabular-nums;
}

h1, h2, h3, p, ul, ol, dl, dd, figure { margin: 0; padding: 0; }
ul, ol { list-style: none; }
i { font-style: normal; }

a { color: var(--blue-text); text-underline-offset: 0.18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--blue); outline-offset: 2px; }

code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.88em; }

.skip {
  position: absolute;
  left: 16px;
  top: -60px;
  padding: 8px 12px;
  background: var(--ink);
  color: var(--paper);
}
.skip:focus { top: 12px; }

/* The sheet: a margin column and a main column split by the red rule. */
.band {
  display: grid;
  grid-template-columns: var(--margin) minmax(0, 1fr);
  max-width: var(--sheet);
  margin: 0 auto;
}
.margin { padding: 72px 24px 0 32px; }
.main {
  min-width: 0;
  padding: 72px 32px 72px var(--gutter);
  border-left: 1.5px solid var(--red);
}
.hero .margin, .hero .main { padding-top: 64px; }

h1 {
  max-width: 25ch;
  font: 450 clamp(2.125rem, 4.7vw, 3.6rem)/1.1 var(--display);
  text-wrap: balance;
  letter-spacing: -0.015em;
}
h2 { font: 600 1.0625rem/1.3 var(--display); }
h3 { font: 600 1.1875rem/1.3 var(--display); }

.who { font: 600 1.25rem/1.2 var(--display); }
.where { margin-top: 6px; color: var(--ink-soft); font-size: 0.9375rem; }

.hero-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 380px);
  gap: 48px;
  align-items: start;
  margin-top: 44px;
}
.hero-body p + p { margin-top: 0.8em; }

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin-top: 22px;
  font-weight: 600;
}

/* Parity readout */
.parity { background: var(--paper); border-top: 2px solid var(--ink); }
.parity figcaption { padding: 10px 0 8px; font-weight: 600; }
.parity dl > div {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 7px 0;
  border-top: 1px solid var(--rule);
}
.parity dt { color: var(--ink-soft); }
.parity dd { text-align: right; }
.parity .zero { padding: 10px 0; border-top-color: var(--ink); }
.parity .zero dt { align-self: center; color: var(--ink); font-weight: 600; }
.parity .zero dd { font: 600 1.875rem/1 var(--display); }
.parity p { padding-top: 8px; border-top: 1px solid var(--rule); color: var(--ink-soft); font-size: 0.9375rem; }

/* Results */
.lede { max-width: 66ch; }
.key {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 28px;
  margin: 20px 0 28px;
  color: var(--ink-soft);
  font-size: 0.9375rem;
}
.key li { display: flex; align-items: center; gap: 9px; }
.key .fp-pt { position: static; transform: none; flex: none; }

.fp {
  --cols: minmax(0, 1fr) minmax(0, 1.5fr) 3.7em minmax(0, 1.5fr) 3.7em;
  margin-inline: -14px;
  padding: 0 14px;
  background: var(--paper);
  border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
}
.fp-head, .fp-row > summary {
  display: grid;
  grid-template-columns: var(--cols);
  column-gap: 14px;
  align-items: center;
}
.fp-head { padding-top: 12px; }
.fp-axis { position: relative; display: block; height: 3.3em; font-size: 0.875rem; color: var(--ink-soft); }
.fp-axis b { display: block; color: var(--ink); font-weight: 600; }
.fp-tick { position: absolute; bottom: 4px; transform: translateX(-50%); }

.fp-row { border-top: 1px solid var(--rule); }
.fp-row > summary { min-height: 58px; padding: 8px 0; cursor: pointer; list-style: none; }
.fp-row > summary::-webkit-details-marker { display: none; }
.fp-row > summary:hover .fp-name { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
.fp-row[open] > summary .fp-name::before { transform: rotate(90deg); }

.fp-name { position: relative; display: block; padding-left: 16px; font-weight: 600; line-height: 1.3; }
.fp-head .fp-name { padding: 0; }
.fp-row .fp-name::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 0.38em;
  border-left: 7px solid var(--ink-soft);
  border-block: 4.5px solid transparent;
  transition: transform 120ms ease-out;
}
.fp-name small { display: block; color: var(--ink-soft); font-size: 0.875rem; font-weight: 400; }
.fp-val { text-align: right; }

.fp-plot { position: relative; display: block; align-self: stretch; min-height: 42px; }
.fp-plot::before {
  content: "";
  position: absolute;
  left: var(--zero);
  top: -9px;
  bottom: -9px;
  width: 1px;
  background: var(--ink);
}
.fp-ci {
  position: absolute;
  top: 50%;
  height: 2px;
  margin-top: -1px;
  background: var(--blue);
  transition: left 800ms cubic-bezier(.2, .7, .2, 1) var(--delay, 0ms), width 800ms cubic-bezier(.2, .7, .2, 1) var(--delay, 0ms);
}
.fp-ci.null { background: var(--red); }
.fp-pt {
  position: absolute;
  top: 50%;
  display: block;
  width: 9px;
  height: 9px;
  background: var(--blue);
  box-shadow: 0 0 0 1px var(--paper);
  transform: translate(-50%, -50%);
  transition: left 800ms cubic-bezier(.2, .7, .2, 1) var(--delay, 0ms);
}
.fp-pt.null { border: 2px solid var(--red); border-radius: 50%; background: var(--paper); }

/* Pulled back to zero by script.js until the chart scrolls into view. */
.fp.waiting .fp-ci { left: var(--zero) !important; width: 0 !important; }
.fp.waiting .fp-pt { left: var(--zero) !important; }

.fp-note { max-width: 66ch; padding: 0 0 16px 16px; }
.fp-source { margin-top: 6px; color: var(--ink-soft); font-size: 0.9375rem; }

.fp-table { margin-top: 14px; font-size: 0.9375rem; }
.fp-table > summary { cursor: pointer; font-weight: 600; }
.fp-table-scroll { margin-top: 10px; overflow-x: auto; background: var(--paper); }
.fp-table table { width: 100%; min-width: 760px; border-collapse: collapse; }
.fp-table th, .fp-table td { padding: 7px 12px 7px 0; border-bottom: 1px solid var(--rule); text-align: left; vertical-align: top; }
.fp-table thead th { border-bottom: 2px solid var(--ink); }
.fp-table tbody th { font-weight: 600; }

.offaxis { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 40px; margin-top: 44px; }
.offaxis article { padding-top: 12px; background: var(--paper); border-top: 2px solid var(--red); }
.offaxis p { margin-top: 8px; }

.more { max-width: 66ch; margin-top: 32px; }

/* Upstream */
.ledger { border-top: 2px solid var(--ink); background: var(--paper); }
.ledger li {
  display: grid;
  grid-template-columns: minmax(0, 15em) minmax(0, 1fr) 6.2em;
  gap: 8px 24px;
  padding: 14px 0;
  border-bottom: 1px solid var(--rule);
}
.ledger.now li { grid-template-columns: minmax(0, 15em) minmax(0, 1fr); }
.ledger h3 { font: 600 1.0625rem/1.4 var(--body); }
.ledger time { color: var(--ink-soft); font-size: 0.9375rem; text-align: right; }
.more a { white-space: nowrap; }

.prose h3 { max-width: 30ch; font: 450 1.75rem/1.2 var(--display); }
.prose p { max-width: 66ch; margin-top: 14px; }

.builds { background: var(--paper); border-top: 2px solid var(--ink); }
.builds > div {
  display: grid;
  grid-template-columns: minmax(0, 15em) minmax(0, 1fr);
  gap: 4px 24px;
  padding: 14px 0;
  border-bottom: 1px solid var(--rule);
}
.builds dt { font-weight: 600; }
.builds dd { max-width: 60ch; }

.timeline { background: var(--paper); border-top: 2px solid var(--ink); }
.timeline li {
  display: grid;
  grid-template-columns: minmax(0, 11em) minmax(0, 1fr);
  gap: 2px 24px;
  padding: 9px 0;
  border-bottom: 1px solid var(--rule);
}
.timeline .when { color: var(--ink-soft); }

footer.band .main { padding-bottom: 96px; }
.closing { max-width: 22ch; font: 450 clamp(1.75rem, 3.6vw, 2.5rem)/1.15 var(--display); }

@media (max-width: 1040px) {
  :root { --margin: 150px; --gutter: 28px; }
  .margin { padding-left: 20px; }
  .hero-body { grid-template-columns: minmax(0, 1fr); gap: 36px; }
  .parity { max-width: 460px; }
  .fp { --cols: minmax(0, 1fr) 3.9em minmax(0, 1fr) 3.9em; }
  .fp-head .fp-name { display: none; }
  .fp-row > summary { row-gap: 2px; }
  .fp-row .fp-name { grid-column: 1 / -1; }
  .fp-plot { min-height: 34px; }
  .fp-plot::before { top: 0; }
}

@media (max-width: 720px) {
  .band { display: block; }
  .margin { padding: 44px 16px 12px; }
  .main { padding: 0 16px 28px; border-left: 0; }
  .hero .margin { padding-top: 28px; border-bottom: 1.5px solid var(--red); padding-bottom: 14px; }
  .hero .main { padding-top: 24px; }
  h2 { font-size: 1.375rem; }
  .fp { --cols: minmax(0, 1fr) minmax(0, 1fr); margin-inline: 0; padding-inline: 10px; }
  .fp-head .fp-val { display: none; }
  .fp-axis { height: 3.1em; font-size: 0.8125rem; }
  .fp-row .fp-val { display: none; }
  .fp-head, .fp-row > summary { column-gap: 20px; }
  .fp-plot { min-height: 30px; }
  .fp-plot::before { top: 0; bottom: -8px; }
  .offaxis { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .ledger li, .builds > div, .timeline li { grid-template-columns: minmax(0, 1fr); }
  .ledger time { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .fp-ci, .fp-pt, .fp-row .fp-name::before { transition: none; }
}

@media (forced-colors: active) {
  .fp-pt, .fp-ci, .fp-seed, .fp-plot::before, .meter-row i, .meter-limit { forced-color-adjust: none; }
  .seg button[aria-pressed="true"], .seg-toggle[aria-pressed="true"] { forced-color-adjust: none; background: Highlight; color: HighlightText; }
  .fix-tabs button[aria-selected="true"] { border-bottom-color: Highlight; }
}

@media print {
  body { background: none; }
  .links, .fp-table > summary { break-inside: avoid; }
}

/* Contributions page */
.who a, footer h2 a { color: inherit; text-decoration: none; }
.who a:hover, footer h2 a:hover { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
.page-lede { margin-top: 28px; }

.contrib { background: var(--paper); border-top: 2px solid var(--ink); }
.contrib > li {
  display: grid;
  grid-template-columns: minmax(0, 13.5em) minmax(0, 1fr);
  gap: 6px 28px;
  padding: 18px 0;
  border-bottom: 1px solid var(--rule);
}
.contrib h3 { font: 600 1.0625rem/1.4 var(--body); }
.contrib-id p { margin-top: 2px; color: var(--ink-soft); font-size: 0.9375rem; }
.contrib-body { max-width: 62ch; }
.contrib-body p + p { margin-top: 0.7em; }
.contrib-body .contrib-status { padding-left: 12px; border-left: 2px solid var(--red); }
.reports { margin-top: 24px; }

@media (max-width: 720px) {
  .contrib > li { grid-template-columns: minmax(0, 1fr); }
}

/* Hero portrait and actions */
.hero-top { display: grid; grid-template-columns: minmax(0, 1fr) 240px; gap: 40px; align-items: start; }
.portrait {
  display: block;
  width: 100%;
  height: auto;
  padding: 7px;
  background: #fff;
  box-shadow: 0 1px 0 var(--rule), 2px 3px 0 var(--rule);
  transform: rotate(1.2deg);
}
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.actions a {
  display: inline-block;
  padding: 8px 14px;
  border: 1.5px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  font-weight: 600;
  text-decoration: none;
}
.actions a:hover { background: var(--square); }
.actions a.primary { background: var(--ink); color: var(--paper); }
.actions a.primary:hover { background: var(--blue-text); border-color: var(--blue-text); }
.closing + .actions { margin-top: 26px; }

/* Experiment explorer */
.fp-tools { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 14px; margin-bottom: 18px; }
.fp-tools[hidden] { display: none; }
.seg { display: inline-flex; }
.seg button, .seg-toggle {
  min-height: 38px;
  padding: 6px 12px;
  border: 1.5px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  font: 600 0.9375rem/1.2 var(--body);
  cursor: pointer;
}
.seg button + button { border-left-width: 0; }
.seg button:hover, .seg-toggle:hover { background: var(--square); }
.seg button[aria-pressed="true"], .seg-toggle[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.fp-count { color: var(--ink-soft); font-size: 0.9375rem; }

.fp-seed {
  position: absolute;
  top: 50%;
  display: none;
  width: 2px;
  height: 16px;
  margin: -8px 0 0 -1px;
  background: var(--ink);
}
.show-seeds .fp-seed { display: block; }
.show-seeds .fp-pt { opacity: 0.45; }
.fp-row[hidden] { display: none; }
.fp[data-corpus="english"] .cell-code, .fp[data-corpus="code"] .cell-english { display: none; }
.fp[data-corpus="english"], .fp[data-corpus="code"] { --cols: minmax(0, 1fr) minmax(0, 3fr) 3.7em; }
.fp-note .fp-source + .fp-source { margin-top: 0; }

/* GB10 walkthrough */
.fix { margin-top: 22px; background: var(--paper); border-top: 2px solid var(--ink); border-bottom: 2px solid var(--ink); }
.fix-tabs { display: flex; flex-wrap: wrap; border-bottom: 1px solid var(--rule); }
.fix-tabs[hidden] { display: none; }
.fix-tabs button {
  flex: 1 1 auto;
  min-height: 44px;
  padding: 8px 14px;
  border: 0;
  border-bottom: 3px solid transparent;
  background: none;
  color: var(--ink-soft);
  font: 600 1rem/1.2 var(--body);
  cursor: pointer;
}
.fix-tabs button:hover { color: var(--ink); }
.fix-tabs button[aria-selected="true"] { border-bottom-color: var(--red); color: var(--ink); }
.fix-panel { padding: 20px 0 24px; }
.fix-panel + .fix-panel { border-top: 1px solid var(--rule); }
.stepping .fix-panel + .fix-panel { border-top: 0; }
.fix-panel[hidden] { display: none; }
.fix-panel h3 { font: 450 1.625rem/1.2 var(--display); }
.fix-panel p { max-width: 66ch; margin-top: 12px; }
.fix-panel pre {
  margin: 16px 0 0;
  padding: 12px 14px;
  overflow-x: auto;
  background: var(--ink);
  color: var(--paper);
}
.fix-panel pre code { font-size: 0.875rem; line-height: 1.5; }

.meter { position: relative; max-width: 620px; margin-top: 18px; padding: 30px 0 4px; }
.meter-limit { position: absolute; top: 0; bottom: 0; width: 2px; background: var(--red); }
.meter-limit span { position: absolute; top: 0; right: 8px; color: var(--ink-soft); font-size: 0.875rem; white-space: nowrap; }
.meter-row { position: relative; height: 24px; background: var(--square); }
.meter-row i { position: absolute; left: 0; top: 0; bottom: 0; background: var(--blue); }
.meter-row span { position: absolute; left: 8px; top: 2px; z-index: 1; color: var(--paper); font-weight: 600; font-size: 0.875rem; }
.meter-row b { position: absolute; left: 8px; top: 30px; font-weight: 400; color: var(--ink-soft); font-size: 0.875rem; }
.meter { padding-bottom: 28px; }

.fix-stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; margin-top: 14px; }
.fix-stats dt { color: var(--ink-soft); font-size: 0.9375rem; }
.fix-stats dd { font: 450 1.625rem/1.2 var(--display); }

/* Call form */
.call-form { display: grid; gap: 16px; max-width: 34rem; }
.call-form label { display: grid; gap: 5px; font-weight: 600; }
.call-form input, .call-form textarea {
  width: 100%;
  padding: 9px 10px;
  border: 1.5px solid var(--ink);
  background: #fff;
  color: var(--ink);
  font: 400 1rem/1.4 var(--body);
}
.call-form button {
  justify-self: start;
  min-height: 42px;
  padding: 8px 16px;
  border: 0;
  background: var(--ink);
  color: var(--paper);
  font: 600 1rem/1.2 var(--body);
  cursor: pointer;
}
.call-form button:hover { background: var(--blue-text); }

/* Articles */
.article { font-size: 1.0625rem; }
.article > * { max-width: 68ch; }
.article h2 { margin-top: 1.8em; font: 600 1.5rem/1.25 var(--display); }
.article h3 { margin-top: 1.5em; font: 600 1.1875rem/1.3 var(--display); }
.article p, .article ul, .article ol { margin-top: 0.9em; }
.article ul, .article ol { padding-left: 1.3em; }
.article ul { list-style: disc; }
.article ol { list-style: decimal; }
.article pre { max-width: 100%; margin: 1.1em 0 0; padding: 12px 14px; overflow-x: auto; background: var(--ink); color: var(--paper); }
.article pre code { font-size: 0.875rem; }
.article img { display: block; max-width: 100%; height: auto; margin-top: 1.2em; background: #fff; }

@media (max-width: 1040px) {
  .hero-top { grid-template-columns: minmax(0, 1fr) 190px; gap: 24px; }
  .fp[data-corpus="english"], .fp[data-corpus="code"] { --cols: minmax(0, 1fr) 3.9em; }
}

@media (max-width: 720px) {
  .hero-top { grid-template-columns: minmax(0, 1fr); }
  .portrait { grid-row: 1; width: 170px; }
  .fp[data-corpus="english"], .fp[data-corpus="code"] { --cols: minmax(0, 1fr); }
  .fix-stats { grid-template-columns: minmax(0, 1fr); gap: 10px; }
  .fix-tabs button { flex: 1 1 45%; }
}