:root {
  color-scheme: light dark;
  --background: #f4f1e8;
  --surface: #fffdf6;
  --text: #1d241f;
  --muted: #667067;
  --border: #d2d6cc;
  --accent: #204f3a;
  --accent-strong: #143c2b;
  --accent-soft: #dce9df;
  font-family: ui-serif, Georgia, "Noto Serif SC", "Songti SC", serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-size: 17px;
  line-height: 1.75;
}

a {
  color: var(--accent);
  text-underline-offset: 0.2em;
  text-decoration-thickness: 0.08em;
}

a:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 4px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -5rem;
  padding: 0.6rem 0.9rem;
  background: var(--text);
  color: var(--background);
  z-index: 10;
}

.skip-link:focus {
  top: 1rem;
}

.site-header,
main,
footer {
  width: min(100% - 2rem, 920px);
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.brand {
  color: var(--text);
  font-weight: 750;
  text-decoration: none;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.92rem;
}

nav a {
  text-decoration: none;
}

nav a[aria-current="page"] {
  font-weight: 750;
  text-decoration: underline;
}

main {
  padding-block: 4.5rem;
}

.hero {
  max-width: 780px;
  margin-bottom: 5rem;
}

.hero.compact {
  margin-bottom: 2.5rem;
}

.eyebrow,
.meta,
.card-index {
  color: var(--muted);
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  line-height: 1.22;
}

h1 {
  margin-block: 0.6rem 1.15rem;
  font-size: clamp(2.25rem, 7vw, 4.8rem);
  letter-spacing: -0.04em;
}

h2 {
  margin-top: 2.8rem;
  font-size: clamp(1.45rem, 3vw, 2rem);
}

h3 {
  margin-block: 0.5rem;
  font-size: 1.25rem;
}

.lead {
  color: var(--muted);
  font-size: clamp(1.05rem, 2.5vw, 1.28rem);
}

.primary-link {
  display: inline-flex;
  gap: 0.55rem;
  margin-top: 1rem;
  padding: 0.72rem 1rem;
  border-radius: 0.4rem;
  background: var(--accent);
  color: #fff;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-weight: 700;
  text-decoration: none;
}

.section-heading {
  max-width: 620px;
  margin-bottom: 1.5rem;
}

.section-heading h2 {
  margin-top: 0.3rem;
}

.cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.cards article,
.note-list article {
  padding: 1.4rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
}

.card-index {
  margin: 0;
}

.principles {
  margin-top: 5rem;
}

.principles ol {
  padding-left: 1.3rem;
}

.principles li + li {
  margin-top: 0.8rem;
}

.note-list {
  display: grid;
  gap: 1rem;
}

.note-list h2 {
  margin-block: 0.4rem;
}

.note-list .meta {
  margin: 0;
}

.prose {
  max-width: 750px;
}

.prose li + li {
  margin-top: 0.65rem;
}

.prose dt {
  margin-top: 1rem;
  font-weight: 750;
}

.prose dd {
  margin-left: 0;
  color: var(--muted);
}

aside {
  margin-top: 2.5rem;
  padding: 1.15rem 1.3rem;
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
}

.error-page {
  min-height: 80vh;
  display: grid;
  align-content: center;
  justify-items: start;
}

footer {
  padding-block: 1.6rem 3rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.86rem;
}

footer p {
  margin: 0.25rem 0;
}

@media (max-width: 720px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

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

  main {
    padding-block: 3rem;
  }
}

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

@media (prefers-color-scheme: dark) {
  :root {
    --background: #141916;
    --surface: #1c231e;
    --text: #eef1e9;
    --muted: #adb7ae;
    --border: #3a443c;
    --accent: #9bd0af;
    --accent-strong: #b9dec7;
    --accent-soft: #233b2d;
  }

  .primary-link {
    color: #102219;
  }
}