:root {
  color-scheme: light dark;
  --brand: #078b96;
  --brand-soft: #e8f6f7;
  --ink: #172126;
  --muted: #66747c;
  --surface: #ffffff;
  --background: #f4f7f8;
  --border: #d9e4e6;
  --notice: #fff7e8;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--background);
  line-height: 1.65;
}

a { color: var(--brand); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  backdrop-filter: blur(16px);
}

.nav {
  max-width: 960px;
  min-height: 64px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 16px;
}

.nav-links a { text-decoration: none; }
.nav-links a[aria-current="page"] { color: var(--ink); font-weight: 700; }

main {
  max-width: 840px;
  margin: 0 auto;
  padding: 56px 24px 80px;
}

.hero {
  padding: 48px;
  border: 1px solid var(--border);
  border-radius: 28px;
  background: linear-gradient(145deg, var(--surface), var(--brand-soft));
}

.app-logo {
  display: block;
  width: clamp(112px, 24vw, 160px);
  height: auto;
  margin: 0 0 28px;
  border-radius: 24%;
  box-shadow: 0 18px 44px color-mix(in srgb, #061a50 26%, transparent);
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--brand);
  font-weight: 750;
}

h1, h2, h3 {
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 { margin: 0 0 16px; font-size: clamp(2rem, 6vw, 3.8rem); }
h2 { margin-top: 2.2em; }
h3 { margin-top: 1.6em; }

.lede { color: var(--muted); font-size: 1.08rem; }

.language-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 32px;
}

.language-card,
.document-card {
  display: block;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
}

.language-card:hover,
.language-card:focus-visible,
.document-card:hover,
.document-card:focus-visible {
  border-color: var(--brand);
  outline: 3px solid color-mix(in srgb, var(--brand) 18%, transparent);
}

.document-list {
  display: grid;
  gap: 14px;
  margin-top: 28px;
}

.meta,
.small { color: var(--muted); }

.notice {
  margin: 28px 0;
  padding: 18px 20px;
  border-left: 4px solid #c77b00;
  border-radius: 10px;
  background: var(--notice);
}

ul, ol { padding-left: 1.35em; }
li + li { margin-top: 0.45em; }

.site-footer {
  max-width: 840px;
  margin: 0 auto;
  padding: 24px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  text-align: center;
}

@media (max-width: 680px) {
  .nav { align-items: flex-start; padding-block: 14px; }
  .nav-links { gap: 10px 14px; font-size: 0.92rem; }
  main { padding-top: 32px; }
  .hero { padding: 28px 22px; border-radius: 22px; }
  .language-grid { grid-template-columns: 1fr; }
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #eef5f6;
    --muted: #afbec3;
    --surface: #172126;
    --background: #0f1619;
    --border: #334247;
    --brand-soft: #17363a;
    --notice: #332817;
  }
}