:root {
  color-scheme: light;
  /* Converge web basePalette; accessible blue from marketing primary-100. */
  --paper: #f8fafc;
  --ink: #0f172a;
  --muted: #475569;
  --brand: #38b4fa;
  --brand-strong: #003eb3;
  --accent: #ffc108;
  --line: #e2e8f0;
  --white: #fff;
  --code-bg: #eef2f7;
  --wash: color-mix(in srgb, var(--brand) 10%, var(--white));
  --space: 1rem;
  --radius: 0.25rem;
  font-family:
    system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
::selection {
  background: var(--accent);
  color: var(--ink);
}
a {
  color: var(--brand-strong);
  text-underline-offset: 0.2em;
}
a:hover {
  text-decoration-thickness: 0.14em;
}
:focus-visible {
  outline: 3px solid var(--brand-strong);
  outline-offset: 4px;
}
h1,
h2,
h3 {
  line-height: 1.2;
  letter-spacing: -0.025em;
}
h1 {
  font-size: clamp(2rem, 4.5vw, 3.6rem);
  margin: 0.5rem 0 1.25rem;
}
h2 {
  font-size: 1.5rem;
}
h3 {
  font-size: 1.25rem;
}
p {
  margin: 0 0 1rem;
}
.site-header,
main,
footer {
  max-width: 76rem;
  margin-inline: auto;
  padding-inline: 2.5rem;
}
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
  padding-block: 1.5rem;
  border-bottom: 1px solid var(--line);
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.2rem;
  text-decoration: none;
  color: var(--ink);
}
.brand-logo {
  display: block;
  flex-shrink: 0;
  width: 2.5rem;
  height: 2.5rem;
}
.brand-label {
  font-size: 0.875rem;
  color: var(--muted);
  font-weight: 400;
  padding-left: 0.6rem;
  border-left: 1px solid var(--line);
}
.site-header nav {
  display: flex;
  gap: 1.5rem;
  font-size: 0.875rem;
}
.site-header nav a {
  text-decoration: none;
}
.hero {
  padding-block: 4.5rem 3.5rem;
  max-width: 50rem;
}
.hero > p:not(.eyebrow),
.lead {
  color: var(--muted);
  font-size: 1.125rem;
}
.eyebrow {
  color: var(--brand-strong);
  font-size: 0.8rem;
  font-weight: 650;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}
.search-form {
  margin-block: 2rem;
  max-width: 44rem;
}
.search-form label {
  display: block;
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
  font-weight: 600;
}
.search-form > div {
  display: flex;
  gap: 0.75rem;
}
.search-form input {
  min-width: 0;
  flex: 1;
  font: inherit;
  padding: 0.875rem 1rem;
  border: 1px solid var(--muted);
  border-radius: var(--radius);
  background: var(--white);
  color: var(--ink);
  caret-color: var(--brand-strong);
}
.search-form input::placeholder {
  color: var(--muted);
}
button {
  cursor: pointer;
  padding: 0.875rem 1.25rem;
  border: 1px solid var(--brand-strong);
  border-radius: var(--radius);
  background: var(--brand);
  color: var(--ink);
  font: inherit;
  font-weight: 600;
}
button:hover {
  background: var(--brand-strong);
  color: var(--white);
}
.start {
  padding-block: 0 3rem;
}
.start h2 {
  font-size: 1rem;
  margin: 0 0 1rem;
}
.quick-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
}
.quick-links a {
  text-decoration: none;
  font-weight: 600;
}
.quick-links span {
  margin-left: 0.5rem;
}
.browse {
  padding-block: 2.5rem 4.5rem;
  border-top: 1px solid var(--line);
}
.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 2rem;
}
.section-heading h2 {
  margin: 0;
}
.section-heading p {
  color: var(--muted);
  font-size: 0.875rem;
  margin: 0;
}
.topic-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 2.5rem;
}
.topic-number {
  color: var(--muted);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  margin: 0 0 0.75rem;
}
.topic h3 {
  margin: 0 0 0.75rem;
}
.topic h3 a {
  text-decoration: none;
}
.topic > p:not(.topic-number) {
  font-size: 0.875rem;
  color: var(--muted);
  min-height: 3rem;
}
.article-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.article-list li {
  border-top: 1px solid var(--line);
}
.article-list a {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 0.75rem;
  text-decoration: none;
  color: var(--ink);
  font-size: 0.875rem;
}
.article-list a:hover {
  color: var(--brand-strong);
}
.article-list span {
  color: var(--brand-strong);
}
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  padding-block: 2rem;
  font-size: 0.875rem;
  color: var(--muted);
}
.category,
.search-page {
  max-width: 50rem;
  padding-block: 1rem 5rem;
  min-height: 65vh;
}
.search-page {
  padding-top: 3rem;
}
.category .article-list {
  margin-top: 2.5rem;
}
.category .article-list a {
  font-size: 1rem;
}
.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 46rem) minmax(12rem, 1fr);
  gap: 4rem;
  padding-bottom: 4rem;
}
.article-layout h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
}
.article-meta {
  color: var(--muted);
  font-size: 0.8rem;
  margin-block: 1.5rem;
}
.notice {
  background: var(--wash);
  border-left: 1px solid var(--brand-strong);
  padding: 1.25rem;
  margin-bottom: 2rem;
  font-size: 0.875rem;
}
.notice p {
  margin: 0.5rem 0 0;
}
.prose h2 {
  margin: 2.5rem 0 1rem;
  scroll-margin-top: 2rem;
}
.prose h3 {
  margin-top: 2rem;
}
.prose li {
  margin-bottom: 0.5rem;
}
.prose code {
  overflow-wrap: anywhere;
}
.prose a {
  overflow-wrap: anywhere;
}
.article-sidebar {
  align-self: start;
  position: sticky;
  top: 2rem;
  border-left: 1px solid var(--line);
  padding-left: 1.5rem;
}
.article-sidebar h2 {
  font-size: 0.875rem;
  margin-top: 0;
}
.article-sidebar ul {
  padding: 0;
  list-style: none;
  margin-bottom: 2rem;
}
.article-sidebar li {
  margin: 0.75rem 0;
}
.article-sidebar a {
  font-size: 0.875rem;
}
.still-help {
  border-top: 1px solid var(--line);
  margin-top: 3rem;
  padding-top: 1.5rem;
}
.still-help h2 {
  font-size: 1.25rem;
}
.results {
  padding: 0;
  list-style: none;
}
.results li {
  border-top: 1px solid var(--line);
  padding-block: 1.5rem;
}
.results h2 {
  font-size: 1.25rem;
  margin: 0.25rem 0 0.75rem;
}
.results .result-meta {
  color: var(--muted);
  font-size: 0.8rem;
  margin: 0;
}
.results p {
  overflow-wrap: anywhere;
}
footer {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  border-top: 1px solid var(--line);
  padding-block: 2rem;
  color: var(--muted);
  font-size: 0.8rem;
}
footer > span:first-child {
  margin-right: auto;
}
.skip {
  position: absolute;
  top: -10rem;
  left: 1rem;
  z-index: 1;
  background: var(--white);
  padding: 0.75rem;
}
.skip:focus {
  top: 1rem;
}
@media (max-width: 60rem) {
  .topic-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .article-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 2rem;
  }
  .article-sidebar {
    position: static;
    grid-row: 1;
  }
}
@media (max-width: 38rem) {
  .site-header,
  main,
  footer {
    padding-inline: 1.25rem;
  }
  .site-header {
    flex-wrap: wrap;
    gap: 1rem;
  }
  .brand-label {
    font-size: 0.8rem;
  }
  .site-header nav {
    width: 100%;
    justify-content: space-between;
  }
  .hero {
    padding-block: 2.5rem 2rem;
  }
  .topic-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 2rem;
  }
  .section-heading {
    display: block;
  }
  .section-heading p {
    margin-top: 0.75rem;
  }
  .topic > p:not(.topic-number) {
    min-height: auto;
  }
  .search-form > div {
    gap: 0.5rem;
  }
  button {
    padding-inline: 0.875rem;
  }
  .search-form input {
    padding-inline: 0.75rem;
  }
}
@media (prefers-reduced-motion: no-preference) {
  a,
  button {
    transition:
      color 120ms ease,
      background-color 120ms ease;
  }
}

/* Dark mode: follows the system unless the reader picks light/dark (theme.js). */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
  color-scheme: dark;
  --paper: #0b1220;
  --ink: #e6edf6;
  --muted: #a3b3c7;
  --brand-strong: #8ccfff;
  --line: #24344d;
  --white: #121c2e;
  --code-bg: #1a2740;
  --wash: color-mix(in srgb, var(--brand) 14%, var(--white));
  }
}
:root[data-theme='dark'] {
  color-scheme: dark;
  --paper: #0b1220;
  --ink: #e6edf6;
  --muted: #a3b3c7;
  --brand-strong: #8ccfff;
  --line: #24344d;
  --white: #121c2e;
  --code-bg: #1a2740;
  --wash: color-mix(in srgb, var(--brand) 14%, var(--white));
}
.prose code {
  background: var(--code-bg);
  color: var(--ink);
  padding: 0.1em 0.35em;
  border-radius: var(--radius);
}
.prose pre {
  background: var(--code-bg);
  color: var(--ink);
  padding: 1rem;
  border-radius: 0.5rem;
  overflow-x: auto;
}
.prose pre code {
  padding: 0;
}
.prose img {
  max-width: 100%;
  height: auto;
}
.theme-toggle {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 2px;
  background: var(--white);
}
html:not([data-theme-pref]) .theme-toggle {
  display: none;
}
.theme-toggle button {
  font: inherit;
  font-size: 0.8rem;
  border: 0;
  background: transparent;
  color: var(--muted);
  padding: 0.2rem 0.65rem;
  border-radius: 999px;
  cursor: pointer;
}
.theme-toggle button[aria-pressed='true'] {
  background: var(--brand);
  color: #0f172a;
  font-weight: 600;
}
.site-header nav {
  align-items: center;
  flex-wrap: wrap;
}
.video {
  margin: 0 0 2rem;
}
.video-frame {
  position: relative;
  aspect-ratio: 16 / 9;
  border-radius: 0.75rem;
  overflow: hidden;
  background: #0b1b2e;
  border: 1px solid var(--line);
  box-shadow: 0 12px 40px rgb(15 23 42 / 0.18);
}
.video-frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
.video figcaption {
  color: var(--muted);
  font-size: 0.875rem;
  margin-top: 0.5rem;
}
.video > video {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  border-radius: 0.75rem;
  background: #0b1b2e;
  border: 1px solid var(--line);
  box-shadow: 0 12px 40px rgb(15 23 42 / 0.18);
}