/* 777Puub Guide: one stylesheet, mobile-first, system fonts only. */
:root {
  --bg: #f8f6f1;
  --card: #ffffff;
  --ink: #17212b;
  --muted: #47525e;
  --line: #d5dae0;
  --accent: #0b5d61;
  --accent-dark: #084649;
  --accent-soft: #e4f1ef;
  --warn-ink: #6b3c00;
  --warn-soft: #fff1d6;
  --warn-line: #d9a047;
  --stop-ink: #8c1d18;
  --stop-soft: #fdeceb;
  --stop-line: #dc968f;
  --max: 46rem;
}

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

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.65;
  overflow-wrap: break-word;
}

img,
svg {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--accent-dark);
  text-decoration-thickness: 0.14em;
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

h1,
h2,
h3 {
  line-height: 1.25;
  margin: 0 0 0.5em;
  text-wrap: balance;
}

h1 {
  font-size: 1.7rem;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 1.45rem;
  margin-top: 2.4rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--line);
}

h3 {
  font-size: 1.15rem;
  margin-top: 1.6rem;
}

h2[id],
h3[id],
section[id] {
  scroll-margin-top: 1rem;
}

p,
ul,
ol,
dl,
table,
figure {
  margin: 0 0 1.1rem;
}

ul,
ol {
  padding-left: 1.35rem;
}

li {
  margin-bottom: 0.45rem;
}

strong {
  font-weight: 700;
}

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1rem;
}

/* Skip link */
.skip {
  position: absolute;
  left: 0.5rem;
  top: -4rem;
  z-index: 10;
  padding: 0.75rem 1rem;
  background: var(--card);
  color: var(--ink);
  border: 2px solid var(--accent);
  border-radius: 0.4rem;
}

.skip:focus {
  top: 0.5rem;
}

/* Disclosure bar shown on every page */
.notice {
  background: var(--ink);
  color: #ffffff;
  font-size: 0.9375rem;
  line-height: 1.5;
}

.notice p {
  margin: 0;
  padding: 0.7rem 0;
}

.notice strong {
  color: #ffe2a6;
}

/* Header */
.site-header {
  background: var(--card);
  border-bottom: 1px solid var(--line);
}

.site-header .wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  min-height: 3rem;
  color: var(--ink);
  font-weight: 700;
  font-size: 1.1rem;
  text-decoration: none;
}

.brand:hover {
  color: var(--accent-dark);
}

.brand small {
  display: block;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.02em;
}

.site-nav {
  width: 100%;
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0;
  margin: 0 -0.35rem;
  padding: 0;
  list-style: none;
}

.site-nav li {
  margin: 0;
}

.site-nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3rem;
  min-width: 3rem;
  padding: 0 0.35rem;
  color: var(--ink);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 3px solid transparent;
}

.site-nav a:hover {
  border-bottom-color: var(--line);
}

.site-nav a[aria-current="page"] {
  color: var(--accent-dark);
  border-bottom-color: var(--accent);
}

/* Main column */
main {
  padding: 1.5rem 0 3rem;
}

.crumbs {
  font-size: 0.9375rem;
  color: var(--muted);
  margin-bottom: 0.9rem;
}

.crumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.crumbs li {
  display: flex;
  align-items: center;
  min-height: 3rem;
  margin: 0;
}

.crumbs li + li::before {
  content: "\203A";
  margin-right: 0.35rem;
  color: var(--muted);
}

.crumbs a {
  display: inline-flex;
  align-items: center;
  min-height: 3rem;
  min-width: 3rem;
}

.lede {
  font-size: 1.175rem;
  line-height: 1.55;
}

.byline {
  font-size: 0.9375rem;
  color: var(--muted);
}

/* Boxes */
.callout {
  margin: 0 0 1.25rem;
  padding: 1rem 1.1rem;
  background: var(--accent-soft);
  border: 1px solid #b9d8d4;
  border-left: 0.35rem solid var(--accent);
  border-radius: 0.5rem;
}

.callout > :last-child {
  margin-bottom: 0;
}

.callout h2,
.callout h3 {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
  font-size: 1.1rem;
}

.callout--warn {
  background: var(--warn-soft);
  border-color: var(--warn-line);
  border-left-color: #b26a00;
}

.callout--warn a {
  color: var(--warn-ink);
}

.callout--stop {
  background: var(--stop-soft);
  border-color: var(--stop-line);
  border-left-color: var(--stop-ink);
}

.callout--stop a {
  color: var(--stop-ink);
}

.glance {
  margin: 0 0 1.25rem;
  padding: 1rem 1.1rem 0.3rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
}

.glance h2,
.glance h3 {
  margin: 0;
  padding: 0;
  border: 0;
  font-size: 1.05rem;
}

.facts {
  margin: 0;
}

.facts div {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--line);
}

.facts div:last-child {
  border-bottom: 0;
}

.facts dt {
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}

.facts dd {
  margin: 0.15rem 0 0;
}

.facts--plain dt {
  font-size: 1rem;
  letter-spacing: 0;
  text-transform: none;
  color: var(--ink);
}

.toc {
  margin: 0 0 1.25rem;
  padding: 1rem 1.1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
}

.toc h2 {
  margin: 0 0 0.4rem;
  padding: 0;
  border: 0;
  font-size: 1.05rem;
}

.toc ol {
  margin: 0;
  padding-left: 1.35rem;
}

.toc li {
  margin: 0;
}

.toc a {
  display: inline-block;
  min-width: 3rem;
  padding: 0.65rem 0;
}

.checklist {
  padding-left: 0;
  list-style: none;
}

.checklist li {
  position: relative;
  padding-left: 1.9rem;
}

.checklist li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  top: 0.12rem;
  width: 1.3rem;
  height: 1.3rem;
  border-radius: 50%;
  background: var(--accent);
  color: #ffffff;
  font-size: 0.85rem;
  font-weight: 700;
  line-height: 1.3rem;
  text-align: center;
}

.steps li {
  padding-left: 0.2rem;
  margin-bottom: 0.7rem;
}

.steps li::marker {
  font-weight: 700;
  color: var(--accent-dark);
}

/* Tables scroll inside their own box on small screens */
.table-wrap {
  margin: 0 0 1.25rem;
  overflow-x: auto;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
}

table {
  width: 100%;
  margin: 0;
  border-collapse: collapse;
  font-size: 0.9875rem;
  font-variant-numeric: tabular-nums;
}

caption {
  padding: 0.8rem 0.8rem 0.6rem;
  text-align: left;
  font-weight: 700;
  caption-side: top;
}

th,
td {
  padding: 0.6rem 0.45rem;
  text-align: left;
  vertical-align: top;
  border-top: 1px solid var(--line);
}

th:first-child,
td:first-child {
  padding-left: 0.8rem;
}

th:last-child,
td:last-child {
  padding-right: 0.8rem;
}

thead th {
  background: #eef1f4;
  font-size: 0.9375rem;
}

tbody th {
  font-weight: 700;
}

.num th:not(:first-child),
.num td {
  text-align: right;
}

.num td {
  white-space: nowrap;
}

.mx {
  display: block;
  color: var(--muted);
}

.note {
  font-size: 0.9375rem;
  color: var(--muted);
}

/* Diagrams */
figure {
  padding: 1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
}

figure img {
  display: block;
  width: 100%;
  max-width: 30rem;
  margin: 0 auto;
}

figcaption {
  margin-top: 0.7rem;
  font-size: 0.9375rem;
  color: var(--muted);
}

/* Cards that link to the two topic pages */
.cards {
  display: grid;
  gap: 1rem;
  margin: 0 0 1.25rem;
  padding: 0;
  list-style: none;
}

.cards li {
  margin: 0;
  padding: 1rem 1.1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
}

.cards h3 {
  margin-top: 0;
}

.cards p:last-child {
  margin-bottom: 0;
}

.more {
  display: inline-block;
  padding: 0.7rem 0;
  font-weight: 700;
}

/* FAQ */
.faq h3 {
  margin-top: 1.4rem;
}

.faq div {
  padding-bottom: 0.2rem;
  border-bottom: 1px solid var(--line);
}

.faq div:last-child {
  border-bottom: 0;
}

.formula {
  display: block;
  margin: 0 0 1.1rem;
  padding: 0.75rem 0.9rem;
  background: #eef1f4;
  border-radius: 0.4rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  font-size: 0.95rem;
  overflow-x: auto;
}

/* Footer */
.site-footer {
  background: var(--ink);
  color: #e8ecf0;
  font-size: 0.9375rem;
  padding: 2rem 0 2.5rem;
}

.site-footer a {
  color: #ffffff;
}

.site-footer :focus-visible {
  outline-color: #ffe2a6;
}

.notice :focus-visible {
  outline-color: #ffe2a6;
}

.site-footer ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0 1.25rem;
  margin: 0 0 1rem;
  padding: 0;
  list-style: none;
}

.site-footer li {
  margin: 0;
}

.site-footer li a {
  display: inline-flex;
  align-items: center;
  min-height: 3rem;
  min-width: 3rem;
}

.site-footer p {
  margin: 0 0 0.9rem;
}

.site-footer .age {
  color: #ffe2a6;
  font-weight: 700;
}

@media (min-width: 40em) {
  body {
    font-size: 1.125rem;
  }

  h1 {
    font-size: 2.4rem;
  }

  h2 {
    font-size: 1.65rem;
  }

  h3 {
    font-size: 1.25rem;
  }

  .wrap {
    padding: 0 1.5rem;
  }

  .site-nav {
    width: auto;
  }

  .site-nav ul {
    justify-content: flex-start;
    gap: 0 0.25rem;
    margin: 0;
  }

  .site-nav a {
    padding: 0 0.7rem;
    font-size: inherit;
  }

  main {
    padding-top: 2.25rem;
  }

  .cards {
    grid-template-columns: 1fr 1fr;
  }

  .toc ol {
    columns: 2;
    column-gap: 2rem;
  }

  .facts div {
    display: grid;
    grid-template-columns: 11rem 1fr;
    gap: 1rem;
    align-items: baseline;
  }

  .facts dd {
    margin: 0;
  }

  th,
  td {
    padding: 0.6rem 0.9rem;
  }

  th:first-child,
  td:first-child,
  caption {
    padding-left: 1rem;
  }

  th:last-child,
  td:last-child {
    padding-right: 1rem;
  }
}

@media print {
  .site-nav,
  .skip,
  .toc {
    display: none;
  }

  body {
    background: #ffffff;
  }
}