@font-face {
  font-family: Inter;
  src: url("../fonts/InterVariable.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

:root, :root[data-theme] {
  --pico-font-family: Inter, system-ui, sans-serif;
  --pico-font-size: 100%;
  --pico-border-radius: .6rem;
}

:root:not([data-theme]), :root[data-theme="light"] {
  --pico-background-color: #f6f8fc;
  --pico-color: #23334e;
  --pico-muted-color: #586a84;
  --pico-primary: #225cc0;
  --pico-primary-hover: #174693;
  --pico-h1-color: #11223d;
  --pico-h2-color: #11223d;
  --pico-h3-color: #11223d;
  --line: #d9e1ee;
  --surface: #fff;
  --surface-hover: #edf3ff;
  --accent-soft: #e9f0ff;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --pico-background-color: #0b1220;
    --pico-color: #dbe7ff;
    --pico-muted-color: #a6b3cf;
    --pico-primary: #82b6ff;
    --pico-primary-hover: #b4d4ff;
    --pico-h1-color: #edf3ff;
    --pico-h2-color: #edf3ff;
    --pico-h3-color: #edf3ff;
    --line: #26334a;
    --surface: #101b2d;
    --surface-hover: #15243b;
    --accent-soft: #142843;
  }
}

:root[data-theme="dark"] {
    --pico-background-color: #0b1220;
    --pico-color: #dbe7ff;
    --pico-muted-color: #a6b3cf;
    --pico-primary: #82b6ff;
    --pico-primary-hover: #b4d4ff;
    --pico-h1-color: #edf3ff;
    --pico-h2-color: #edf3ff;
    --pico-h3-color: #edf3ff;
    --line: #26334a;
    --surface: #101b2d;
    --surface-hover: #15243b;
    --accent-soft: #142843;
  }

html { scroll-behavior: smooth; scroll-padding-top: 2rem; }
body { min-height: 100vh; display: flex; flex-direction: column; font-weight: 400; -webkit-font-smoothing: antialiased; }
.container { width: min(1120px, calc(100% - 80px)); max-width: none; padding: 0; }
main.container { flex: 1; padding-block: 0 5rem; }
a { text-underline-offset: .25em; }
a:focus-visible { outline: 2px solid var(--pico-primary); outline-offset: 6px; border-radius: 3px; }
.skip-link { position: fixed; top: 12px; left: 12px; z-index: 10; transform: translateY(-180%); padding: .75rem 1rem; background: var(--surface); }
.skip-link:focus { transform: translateY(0); }
.site-header { display: flex; align-items: center; justify-content: space-between; min-height: 100px; border-bottom: 1px solid var(--line); }
.brand { font-size: 1.35rem; font-weight: 700; color: var(--pico-h1-color); text-decoration: none; letter-spacing: -.04em; }
.site-header nav ul { gap: 1.7rem; margin: 0; }
.site-header nav li { padding: 0; }
.site-header nav a { display: block; margin: 0; padding: .65rem 0; border-radius: 0; font-size: .85rem; font-weight: 500; color: var(--pico-muted-color); position: relative; }
.site-header nav a::after { content: ""; position: absolute; bottom: 0; left: 0; width: 100%; height: 2px; background: var(--pico-primary); transform: scaleX(0); transition: transform .2s; transform-origin: left; }
.site-header nav a:hover, .site-header nav a[aria-current] { color: var(--pico-h1-color); text-decoration: none; }
.site-header nav a:hover::after, .site-header nav a[aria-current]::after { transform: scaleX(1); }
.eyebrow { font-size: .7rem; font-weight: 600; letter-spacing: .16em; text-transform: uppercase; color: var(--pico-primary); margin-bottom: 1.6rem; }
h1 { font-size: clamp(2.6rem, 4.6vw, 3.7rem); font-weight: 500; line-height: 1.1; letter-spacing: -.065em; margin-bottom: 1.7rem; }
.intro { max-width: 440px; line-height: 1.8; color: var(--pico-muted-color); font-size: .98rem; }
.intro p { margin-bottom: 0; }
.primary-link { display: inline-flex; gap: 2rem; align-items: center; padding: .9rem 1.2rem; margin-top: 2rem; color: var(--pico-primary); background: var(--accent-soft); border: 1px solid var(--line); border-radius: 5px; font-size: .85rem; font-weight: 500; text-decoration: none; transition: background .2s, border-color .2s; }
.primary-link:hover { background: var(--surface-hover); border-color: var(--pico-primary); text-decoration: none; }
.primary-link span, .card-arrow, .card-link span { transition: transform .2s; }
.primary-link:hover span { transform: translateY(3px); }
.section-heading { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; padding-block: 3.5rem 2rem; }
.section-heading h1 { font-size: 2rem; font-weight: 500; margin: 0; }
.explore { margin: 0; }
.explore-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.2rem; }
.section-card { display: block; position: relative; padding: 1.7rem 2rem; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); text-decoration: none; transition: border-color .2s, background .2s, transform .2s; }
.section-card:hover { background: var(--surface-hover); border-color: var(--pico-primary); transform: translateY(-3px); text-decoration: none; }
.card-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 2.2rem; }
.section-number { font-size: .65rem; font-weight: 500; letter-spacing: .12em; color: var(--pico-muted-color); }
.card-arrow { color: var(--pico-primary); font-size: 1.25rem; }
.section-card:hover .card-arrow { transform: translate(3px, -3px); }
.section-card h2 { font-size: 1.6rem; font-weight: 500; letter-spacing: -.04em; margin-bottom: .6rem; }
.section-card p { font-size: .85rem; line-height: 1.75; color: var(--pico-muted-color); margin-bottom: 1.8rem; }
.card-link { font-size: .8rem; font-weight: 500; display: flex; justify-content: space-between; color: var(--pico-primary); }
.section-card:hover .card-link span { transform: translateX(4px); }
.site-footer { text-align: center; padding-block: 1.6rem; border-top: 1px solid var(--line); color: var(--pico-muted-color); font-size: .72rem; }
.page-heading { padding-block: 2rem 3.5rem; }
.back-link { display: inline-block; font-size: .8rem; color: var(--pico-muted-color); margin-bottom: 3.5rem; text-decoration: none; }
.back-link span { margin-right: .5rem; }
.page-heading h1 { margin-bottom: 1.2rem; }
.empty-state { display: flex; align-items: center; gap: 3rem; padding: 3.5rem; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); margin-bottom: 1.5rem; }
.empty-mark { font-size: 5rem; font-weight: 300; letter-spacing: -.08em; color: var(--pico-muted-color); opacity: .5; }
.empty-state .eyebrow { margin-bottom: .8rem; }
.empty-state h2 { font-size: 1.35rem; font-weight: 500; letter-spacing: -.03em; }
.empty-state p:last-child { font-size: .9rem; color: var(--pico-muted-color); margin: 0; }
.not-found { padding-block: 6rem; }
.not-found > p:not(.eyebrow) { color: var(--pico-muted-color); }
.reading { max-width: 760px; margin: 2rem auto 0; padding: 0; background: transparent; border: 0; box-shadow: none; }
.reading header { margin: 0 0 2rem; padding: 0; background: transparent; }
@media (max-width: 760px) {
  .container { width: calc(100% - 40px); }
  .explore-grid { grid-template-columns: 1fr; }
  .empty-state { gap: 1.5rem; padding: 2rem; }
  .empty-mark { font-size: 3.5rem; }
  .site-header { min-height: 88px; }
  .site-header nav ul { gap: 1.25rem; }
  .page-heading { padding-bottom: 2.5rem; }
  main.container { padding-bottom: 3rem; }
}
@media (max-width: 420px) {
  .site-header nav ul { gap: 1rem; }
  .site-header nav a { font-size: .78rem; }
  .section-card { padding: 1.5rem; }
  .empty-state { align-items: flex-start; flex-direction: column; gap: 1rem; padding: 1.5rem; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}
.site-footer p { margin: 0; font-size: inherit; }
.site-footer p + p { margin-top: .4rem; }
.page-heading h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); }

.brand-group { display: flex; align-items: center; gap: .6rem; }
.theme-toggle { margin: 0; padding: .35rem; width: 2.5rem; height: 2.5rem; border: 0; background: transparent; box-shadow: none; font-size: 1rem; line-height: 1; }
.theme-toggle:hover { background: var(--accent-soft); }
.theme-toggle:focus-visible { outline: 2px solid var(--pico-primary); outline-offset: 2px; }
@media (max-width: 420px) {
  .brand-group { gap: .2rem; }
  .site-header nav ul { gap: .7rem; }
}