/* Public pages share the same type scale and local fonts as the application. */
:root {
  --app-canvas: #f5f7fb;
  --paper: #fff;
  --ink: #172945;
  --muted: #4d607b;
  --line: #dbe3ef;
  --blue: #2456a5;
  --accent: #a85631;
  --soft: #eef3fa;
  --accent-soft: #fff4ed;
  color-scheme: light;
}
.dark {
  --app-canvas: #0c1930;
  --paper: #132744;
  --ink: #f2f6ff;
  --muted: #c0cee2;
  --line: #365273;
  --blue: #a1c4ff;
  --accent: #f1b08b;
  --soft: #1a3457;
  --accent-soft: #3d2924;
  color-scheme: dark;
}
* {
  box-sizing: border-box;
}
html {
  background: var(--app-canvas);
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
}
body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  background: var(--app-canvas);
  color: var(--ink);
  font-family: var(--nano-font-stack);
  font-size: var(--type-body);
  line-height: var(--line-body);
  overflow-wrap: break-word;
}
a {
  color: var(--blue);
  text-underline-offset: 5px;
}
a:hover {
  text-decoration: underline;
}
:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 4px;
  border-radius: 6px;
}
img {
  max-width: 100%;
  height: auto;
}
.wrap {
  width: min(1200px, calc(100% - 64px));
  margin-inline: auto;
  min-width: 0;
}
.skip {
  position: absolute;
  top: -100px;
  inset-inline-start: 20px;
  z-index: 20;
  background: var(--paper);
  padding: 8px 16px;
}
.skip:focus {
  top: 12px;
}
.top {
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}
.header-layout {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 24px;
  min-height: 88px;
  padding-block: 14px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--ink);
  font-size: 23px;
  font-weight: 700;
  letter-spacing: -0.5px;
  line-height: 1.4;
}
.brand:hover {
  text-decoration: none;
}
.brand > span {
  min-width: 0;
}
.brand-wordmark {
  direction: ltr;
  unicode-bidi: isolate;
}
.brand small {
  display: block;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0;
  font-weight: 400;
  line-height: 1.6;
  max-width: 240px;
}
.brand img {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
}
.header-actions {
  grid-column: 3;
  grid-row: 1;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  min-width: 0;
}
.nav {
  grid-column: 2;
  grid-row: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px 20px;
  flex-wrap: wrap;
  min-width: 0;
}
.nav a {
  display: flex;
  align-items: center;
  min-height: 44px;
  color: var(--muted);
  text-decoration: none;
  font-size: 16px;
  line-height: 1.5;
  text-align: center;
}
.nav a:hover,
.nav a[aria-current='page'] {
  color: var(--blue);
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  max-width: 100%;
  padding: 12px 24px;
  border-radius: var(--radius-control);
  background: #2456a5;
  border: 1px solid #2456a5;
  color: #fff;
  text-decoration: none;
  font-size: 16px;
  line-height: 1.5;
  font-weight: 700;
  text-align: center;
}
.button:hover {
  background: #1c498f;
  color: #fff;
  text-decoration: none;
}
.button.small {
  min-height: 44px;
  padding: 9px 16px;
}
.button.outline {
  background: var(--paper);
  color: var(--blue);
  border-color: var(--line);
}
.button.outline:hover {
  background: var(--soft);
}
.hero {
  padding-block: 56px 40px;
}
.eyebrow {
  font-size: 14px;
  font-weight: 700;
  color: var(--accent);
  margin: 0 0 16px;
}
.eyebrow:before {
  content: '';
  display: inline-block;
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 2px;
  margin-inline-end: 9px;
}
h1 {
  font-size: var(--type-hero);
  line-height: var(--line-heading);
  letter-spacing: var(--tracking-heading);
  margin: 0 0 20px;
  font-weight: 700;
  text-wrap: balance;
}
.intro {
  font-size: 18px;
  color: var(--muted);
  margin: 0;
  max-width: 62ch;
  line-height: var(--line-body);
}
.actions {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-top: 28px;
  flex-wrap: wrap;
}
.text-link {
  font-size: 16px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}
.fine {
  font-size: 14px;
  color: var(--muted);
  margin: 16px 0 0;
  max-width: 60ch;
}
.section {
  padding-block: var(--space-section);
}
.section h2 {
  font-size: var(--type-section);
  line-height: var(--line-heading);
  margin: 0 0 24px;
  letter-spacing: var(--tracking-heading);
}
.section h3 {
  font-size: 20px;
  line-height: var(--line-heading);
  margin: 0 0 12px;
}
.section p {
  margin: 0 0 16px;
}
.section p:last-child {
  margin-bottom: 0;
}
.cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}
.cards.two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
.card {
  border: 1px solid var(--line);
  background: var(--paper);
  border-radius: var(--radius-card);
  padding: 24px;
  min-width: 0;
}
.card p {
  font-size: 16px;
  color: var(--muted);
}
.card a {
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 16px;
}
.step {
  display: inline-grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 16px;
  font-variant-numeric: tabular-nums;
}
.note {
  background: var(--soft);
  border-inline-start: 4px solid var(--blue);
  border-radius: 12px;
  padding: 20px 24px;
  font-size: 16px;
  margin-top: 20px;
}
.warm {
  background: var(--accent-soft);
  border-color: var(--accent);
}
.sample {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 28px;
}
.sample > p:first-child {
  font-size: 14px;
  color: var(--accent);
  margin: 0;
}
.question {
  font-size: 20px;
  font-weight: 700;
  line-height: 1.9;
}
.options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 20px 0;
}
.option {
  background: var(--app-canvas);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 16px;
  line-height: 1.6;
  min-width: 0;
}
.equation {
  display: inline-block;
  direction: ltr;
  unicode-bidi: isolate;
  font-family: Cambria, 'Times New Roman', serif;
  font-size: 1.15em;
  line-height: 1.8;
  max-width: 100%;
  overflow-x: auto;
  vertical-align: middle;
  padding-inline: 4px;
}
.formula {
  display: block;
  direction: ltr;
  unicode-bidi: isolate;
  text-align: center;
  font-family: Cambria, 'Times New Roman', serif;
  font-size: 23px;
  background: var(--soft);
  border-radius: 10px;
  overflow-x: auto;
  padding: 14px 20px;
  white-space: nowrap;
  margin: 16px 0;
}
html body .equation[dir],
html body .formula[dir] {
  font-family: Cambria, 'Times New Roman', serif;
}
.solution {
  border-top: 1px solid var(--line);
  padding-top: 12px;
}
.solution summary {
  color: var(--blue);
  font-weight: 700;
  cursor: pointer;
  min-height: 44px;
  padding-block: 8px;
  font-size: 16px;
}
.solution[open] summary {
  margin-bottom: 12px;
}
.solution p,
.solution li {
  font-size: 16px;
  line-height: var(--line-body);
}
ul,
ol {
  padding-inline-start: 24px;
}
li {
  margin-block: 10px;
}
.crumb {
  color: var(--muted);
  font-size: 14px;
  padding-top: 24px;
  line-height: 1.8;
}
.crumb a {
  text-decoration: none;
}
.article-hero {
  max-width: 900px;
  padding-block: 28px 24px;
}
.article-hero h1 {
  font-size: var(--type-page-title);
}
.article {
  max-width: 800px;
}
.article p,
.article li {
  color: var(--muted);
}
.article strong {
  color: var(--ink);
}
.faq details {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 13px;
  padding: 14px 22px;
  margin: 12px 0;
}
.faq summary {
  cursor: pointer;
  font-weight: 700;
  min-height: 44px;
  line-height: 1.7;
  padding-block: 8px;
}
.faq details p {
  padding-top: 12px;
  color: var(--muted);
  font-size: 16px;
}
.related {
  border-top: 1px solid var(--line);
  margin-top: 16px;
}
.related-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}
.resource-link {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 20px;
  text-decoration: none;
  min-width: 0;
}
.resource-link:hover {
  border-color: var(--blue);
  text-decoration: none;
  background: var(--soft);
}
.resource-title {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.6;
}
.resource-description {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.7;
}
footer {
  margin-top: 24px;
  padding: 28px 0 calc(28px + env(safe-area-inset-bottom));
  background: var(--paper);
  border-top: 1px solid var(--line);
}
.footer-grid {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
}
.footer-grid strong {
  font-size: 20px;
  font-weight: 700;
  direction: ltr;
  unicode-bidi: isolate;
}
.footer-grid p,
.footer-grid small {
  font-size: 14px;
  color: var(--muted);
  margin: 8px 0;
  max-width: 46ch;
}
.footer-grid nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, auto));
  gap: 4px 24px;
  align-items: start;
}
.footer-grid nav a {
  font-size: 14px;
  display: block;
  min-width: 0;
  min-height: 44px;
  padding-block: 9px;
  text-decoration: none;
  overflow-wrap: anywhere;
}
.footer-grid nav a:hover {
  text-decoration: underline;
}
.language-menu {
  position: relative;
  font-size: 14px;
  z-index: 5;
  min-width: 0;
}
.language-menu summary {
  cursor: pointer;
  min-height: 44px;
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--line);
  padding: 9px 12px;
  border-radius: 10px;
  background: var(--paper);
  line-height: 1.5;
}
.language-menu summary:after {
  content: '⌄';
  font-size: 16px;
}
.language-menu summary::-webkit-details-marker {
  display: none;
}
.language-popover {
  position: absolute;
  inset-inline-end: 0;
  top: 100%;
  margin-top: 8px;
  width: 310px;
  max-width: calc(100vw - 32px);
  max-height: min(430px, 65vh);
  overflow-y: auto;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px;
  padding: 10px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 12px 32px #0002;
}
.language-popover a {
  font-family: var(--nano-font-stack);
  min-height: 44px;
  display: flex;
  align-items: center;
  padding: 8px 10px;
  font-size: 14px;
  text-decoration: none;
  border-radius: 7px;
  line-height: 1.7;
}
.language-popover a[aria-current='page'],
.language-popover a:hover {
  background: var(--soft);
  color: var(--blue);
}
@media (max-width: 1199px) {
  .header-layout {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 8px 24px;
  }
  .header-actions {
    grid-column: 2;
    grid-row: 1;
  }
  .nav {
    grid-row: 2;
    grid-column: 1/-1;
    justify-content: flex-start;
    gap: 8px 24px;
  }
  .brand small {
    max-width: 300px;
  }
}
@media (max-width: 850px) {
  .hero {
    padding-top: 36px;
  }
  .cards,
  .cards.two {
    grid-template-columns: 1fr;
  }
  .related-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .footer-grid {
    align-items: flex-start;
    flex-direction: column;
  }
  .hero h1 {
    max-width: 22ch;
  }
}
@media (max-width: 600px) {
  .wrap {
    width: calc(100% - 32px);
  }
  .header-layout {
    grid-template-columns: 1fr;
    gap: 12px;
    padding-block: 16px;
  }
  .brand {
    justify-content: center;
  }
  .brand small {
    text-align: center;
  }
  .header-actions {
    grid-column: 1;
    grid-row: 2;
    justify-content: center;
    flex-wrap: wrap;
  }
  .nav {
    grid-row: 3;
    justify-content: center;
    gap: 4px 18px;
  }
  .nav a {
    font-size: 15px;
  }
  .brand {
    font-size: 22px;
  }
  .intro {
    font-size: 16px;
  }
  .hero {
    padding-block: 32px;
  }
  .hero h1 {
    font-size: 2rem;
  }
  .card,
  .sample {
    padding: 20px;
  }
  .related-links {
    grid-template-columns: 1fr;
  }
  .footer-grid nav {
    gap: 4px 20px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    width: 100%;
  }
  .footer-grid {
    gap: 16px;
  }
  .language-popover {
    position: fixed;
    top: 120px;
    inset-inline: 16px;
    width: auto;
    max-width: none;
  }
  .actions {
    gap: 12px 20px;
  }
  .formula {
    font-size: 20px;
    padding-inline: 12px;
  }
}
@media (max-width: 359px) {
  .options {
    gap: 8px;
  }
  .option {
    padding: 10px 12px;
  }
  .nav {
    gap: 4px 14px;
  }
  .nav a {
    font-size: 14px;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

.home-hero {
  max-width: 820px;
  margin-inline: auto;
  text-align: center;
}
.home-hero .actions {
  justify-content: center;
}
.home-hero h1,
.home-hero .intro {
  margin-inline: auto;
}