/* ── faucet-stream documentation theme ──────────────────────────────────────
   Visual polish layered on top of mdBook's built-in themes via
   `additional-css` (no preprocessor — a bare `mdbook build` still works).
   Loaded after mdBook's own CSS, so these rules win. Tuned for the two themes
   we ship by default (light + navy); the others (rust/coal/ayu) still inherit
   the brand accent and remain fully legible.
   ──────────────────────────────────────────────────────────────────────── */

:root {
  /* faucet-stream brand — a "water/flow" blue, legible on both light and dark. */
  --fs-brand: #2f7fe0;
  --fs-brand-strong: #1f66c2;
  --fs-accent: #0ea5b7;
  --fs-radius: 8px;
  --content-max-width: 46rem; /* a touch wider than default for tables/code */
}

/* ── Typography ──────────────────────────────────────────────────────────── */
html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  scroll-behavior: smooth;
}
.content {
  line-height: 1.65;
}
.content h1,
.content h2,
.content h3,
.content h4 {
  font-weight: 650;
  letter-spacing: -0.01em;
  line-height: 1.25;
}
.content h1 {
  font-size: 2.1rem;
  padding-bottom: 0.3em;
  border-bottom: 2px solid color-mix(in srgb, var(--fs-brand) 30%, transparent);
}
.content h2 {
  margin-top: 2.2rem;
  padding-bottom: 0.2em;
  border-bottom: 1px solid var(--table-border-color, rgba(128, 128, 128, 0.25));
}

/* ── Links ───────────────────────────────────────────────────────────────── */
.content a:not(.header) {
  color: var(--fs-brand);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.12s ease, color 0.12s ease;
}
.content a:not(.header):hover {
  color: var(--fs-brand-strong);
  border-bottom-color: currentColor;
}

/* ── Code ────────────────────────────────────────────────────────────────── */
.content pre {
  border-radius: var(--fs-radius);
  border: 1px solid var(--table-border-color, rgba(128, 128, 128, 0.2));
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}
.content code {
  border-radius: 4px;
}
.content pre > .buttons {
  opacity: 0.7;
}

/* ── Blockquotes → callouts ──────────────────────────────────────────────── */
.content blockquote {
  border-inline-start: 4px solid var(--fs-brand);
  background: color-mix(in srgb, var(--fs-brand) 8%, transparent);
  border-radius: 0 var(--fs-radius) var(--fs-radius) 0;
  padding: 0.6rem 1rem;
  margin-inline: 0;
  color: inherit;
}

/* ── Tables ──────────────────────────────────────────────────────────────── */
.content table {
  border-radius: var(--fs-radius);
  overflow: hidden;
  border-collapse: collapse;
  width: 100%;
}
.content table thead th {
  background: color-mix(in srgb, var(--fs-brand) 12%, transparent);
  font-weight: 650;
  border-bottom: 2px solid color-mix(in srgb, var(--fs-brand) 30%, transparent);
}
.content table td,
.content table th {
  border: 1px solid var(--table-border-color, rgba(128, 128, 128, 0.18));
  padding: 0.45rem 0.7rem;
}

/* ── Sidebar ─────────────────────────────────────────────────────────────── */
.chapter li.chapter-item a.active {
  color: var(--fs-brand);
  font-weight: 650;
}
.sidebar .sidebar-scrollbox {
  padding: 0.75rem 1rem;
}

/* ── Landing hero (used by introduction.md) ──────────────────────────────── */
.fs-hero {
  text-align: center;
  padding: 1.5rem 0 0.5rem;
}
.fs-hero img {
  max-width: 460px;
  width: 70%;
  height: auto;
}
.fs-hero .fs-tagline {
  font-size: 1.25rem;
  opacity: 0.85;
  margin: 0.75rem auto 1.25rem;
  max-width: 34rem;
  line-height: 1.5;
}
.fs-cta {
  display: inline-flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 1rem;
}
.fs-cta a {
  display: inline-block;
  padding: 0.6rem 1.15rem;
  border-radius: var(--fs-radius);
  font-weight: 600;
  border-bottom: none !important;
}
.fs-cta a.primary {
  background: var(--fs-brand);
  color: #fff !important;
}
.fs-cta a.primary:hover {
  background: var(--fs-brand-strong);
}
.fs-cta a.secondary {
  border: 1px solid var(--fs-brand) !important;
  color: var(--fs-brand) !important;
}

/* Card grid for the landing "why" / quick-links sections. */
.fs-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin: 1.25rem 0;
}
.fs-card {
  border: 1px solid var(--table-border-color, rgba(128, 128, 128, 0.22));
  border-radius: var(--fs-radius);
  padding: 1rem 1.1rem;
  background: color-mix(in srgb, var(--fs-brand) 4%, transparent);
}
.fs-card h3 {
  margin-top: 0;
}