/* ────────────────────────────────────────────────────────────────────────
   site.css — MIDI Drums Generator docs: shared design tokens + site chrome
   ────────────────────────────────────────────────────────────────────────
   Extracted from the per-page <style> blocks in docs/site-pages/*.html
   (issue #44, AC group 4) to remove duplication. This file holds only CSS
   that is genuinely shared across multiple pages: design tokens, the base
   reset, the doc-page nav/layout/typography/callout/table/footer "chrome"
   used identically by quickstart.html, recipes.html, reaper.html and
   use-cases.html, plus the accessibility primitives (skip link,
   focus-visible) needed on every page.

   index.html's landing-page-only sections (hero, terminal, stats strip,
   feature cards, genres, drummers, install strip, buttons) and its own
   nav/footer markup are NOT here — they are used by exactly one page, so
   they remain in that page's inline <style> block, same as recipes.html's
   recipe-card CSS and reaper.html's workflow/file-tree CSS stay inline.

   NOTE on --muted: this file changes --muted from the original #5a6f8a to
   #778ca6 to satisfy WCAG 2.1 AA (4.5:1) for body text against --bg — see
   docs/site-pages/ (issue #44 AC group 4) for the audit. No other token
   values changed from what the pages previously agreed on, except
   --sky-dim/--green-dim which are unified to the 0.06 alpha used by 4 of
   the 5 pages (index.html previously used 0.08 for a single hover-state
   tint — the difference is not perceptible).
   ──────────────────────────────────────────────────────────────────────── */

/* ── Design tokens (superset of every value used by any page) ────────── */
:root {
  --bg:          #0a0f17;
  --bg-raised:   #0e1520;
  --panel:       #141d2b;
  --panel-lit:   #1a2438;
  --code-bg:     #080d14;
  --border:      #1c2840;
  --border-lit:  #263650;
  --border-glow: #2e4270;

  --violet:      #a78bfa;
  --violet-d:    #7c5fdb;
  --violet-dim:  rgba(167,139,250,0.08);
  --amber:       #fbbf24;
  --sky:         #38bdf8;
  --sky-dim:     rgba(56,189,248,0.06);
  --green:       #4ade80;
  --green-dim:   rgba(74,222,128,0.06);
  --rose:        #fb7185;

  --text:        #c8d3e0;
  --muted:       #778ca6;
  --dim:         #2d3f57;
  --white:       #eef2f8;

  --mono: 'IBM Plex Mono', 'Courier New', monospace;
  --sans: 'Inter', system-ui, -apple-system, sans-serif;
  --bar-h: 44px;
  --radius: 6px;
}

/* ── Base reset ────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  padding-top: var(--bar-h);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-thumb { background: var(--border-lit); border-radius: 3px; }

/* ── Accessibility: skip link ────────────────────────────────────────────
   Visually hidden until keyboard-focused; jumps past the nav straight to
   the page's main content landmark. */
.skip-link {
  position: absolute;
  top: 0; left: 0;
  transform: translateY(-120%);
  z-index: 2000;
  background: var(--panel-lit);
  color: var(--white);
  border: 1px solid var(--violet);
  border-radius: 0 0 var(--radius) 0;
  padding: 0.6rem 1.1rem;
  font-family: var(--mono);
  font-size: 0.82rem;
  text-decoration: none;
  transition: transform 0.15s;
}
.skip-link:focus {
  transform: translateY(0);
}

/* ── Accessibility: visible focus indicator ──────────────────────────────
   Applies to every interactive element site-wide so no control ever loses
   its focus outline. */
a:focus-visible,
button:focus-visible,
input:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--violet);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ── NAV (doc pages: quickstart / recipes / reaper / use-cases) ─────────── */
#dm-bar {
  position: fixed; top: 0; left: 0; right: 0; height: var(--bar-h); z-index: 1000;
  display: flex; align-items: center; padding: 0 1.75rem;
  background: rgba(10,15,23,0.92);
  backdrop-filter: blur(12px) saturate(1.4);
  -webkit-backdrop-filter: blur(12px) saturate(1.4);
  border-bottom: 1px solid var(--border);
  font-family: var(--mono); font-size: 11px; color: var(--muted); white-space: nowrap;
}
#dm-bar::after {
  content: ''; position: absolute; bottom: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(167,139,250,0.3), transparent);
}
.dm-logo { color: var(--violet); font-weight: 600; font-size: 13px; text-decoration: none; margin-right: .85rem; transition: color .15s; }
.dm-logo::before { content: "> "; color: var(--amber); }
.dm-logo:hover { color: var(--white); }
.dm-badge { font-size: 9px; letter-spacing: .12em; padding: 2px 7px; border-radius: 2px; margin-right: .85rem; color: var(--green); border: 1px solid rgba(74,222,128,.35); background: rgba(74,222,128,.05); }
.dm-sep { color: var(--muted); margin: 0 .85rem; }
.dm-links { margin-left: auto; display: flex; align-items: center; gap: 1.25rem; }
.dm-links a { color: var(--muted); text-decoration: none; font-size: 11px; padding-bottom: 2px; border-bottom: 1px solid transparent; transition: color .15s, border-color .15s; }
.dm-links a:hover, .dm-links a.active { color: var(--violet); border-bottom-color: rgba(167,139,250,.5); }
.dm-links .api-link { color: var(--sky); }
.dm-links .api-link:hover { color: var(--violet); }

/* ── LAYOUT (doc pages) ──────────────────────────────────────────────────── */
.layout { display: grid; grid-template-columns: 228px 1fr; max-width: 1120px; margin: 0 auto; min-height: calc(100vh - var(--bar-h)); }
.toc {
  position: sticky; top: var(--bar-h); height: calc(100vh - var(--bar-h)); overflow-y: auto;
  padding: 2rem 1.25rem; border-right: 1px solid var(--border);
  font-family: var(--mono); font-size: .8rem;
  background: linear-gradient(to bottom, rgba(14,21,32,0.5), transparent);
}
/* Not a heading: these are TOC section labels inside a <nav>, so using
   <h3>/<h4> here would put page-navigation labels ahead of the article's
   own <h1> in the page's one heading outline. Styled to look identical. */
.toc-heading { font-size: .68rem; color: var(--muted); letter-spacing: .18em; text-transform: uppercase; margin-bottom: .75rem; margin-top: 1.5rem; }
.toc-heading:first-child { margin-top: 0; }
.toc a { display: block; color: var(--muted); text-decoration: none; padding: .22rem 0 .22rem .6rem; margin-left: -.6rem; border-left: 2px solid transparent; transition: color .15s, border-color .15s; }
.toc a:hover, .toc a.active { color: var(--violet); border-left-color: rgba(167,139,250,.5); }
.toc a.sub { padding-left: 1.2rem; font-size: .75rem; }
.toc a.sub:hover, .toc a.sub.active { border-left: none; }

article { padding: 2.75rem 3.25rem; max-width: 840px; }

/* ── TYPOGRAPHY (doc pages) ──────────────────────────────────────────────── */
h1 { font-family: var(--mono); font-size: 1.7rem; font-weight: 600; color: var(--white); margin-bottom: .5rem; }
h1::before { content: "# "; color: var(--amber); opacity: .6; }
.subtitle { color: var(--muted); margin-bottom: 2.75rem; font-size: 1rem; }
h2 { font-family: var(--mono); font-size: 1.1rem; font-weight: 600; color: var(--sky); margin: 2.75rem 0 .85rem; padding-top: .5rem; border-top: 1px solid var(--border); }
h2::before { content: "## "; color: var(--amber); opacity: .45; font-size: .9em; }
h3 { font-family: var(--mono); font-size: .95rem; font-weight: 600; color: var(--white); margin: 1.5rem 0 .6rem; }
h3::before { content: "### "; color: var(--amber); opacity: .35; font-size: .85em; }
p { margin: .65rem 0; color: var(--text); }
a { color: var(--sky); text-decoration: none; transition: color .15s; }
a:hover { color: var(--violet); }
code { font-family: var(--mono); font-size: .84em; background: var(--panel-lit); border: 1px solid var(--border); border-radius: 3px; padding: .1em .38em; color: var(--amber); }
pre { margin: 1.1rem 0; border-radius: var(--radius); overflow-x: auto; border: 1px solid var(--border); background: var(--code-bg); box-shadow: 0 4px 24px rgba(0,0,0,0.35); }
pre code { font-size: .84rem; line-height: 1.7; background: none; border: none; color: var(--text); padding: 0; }
ul, ol { margin: .6rem 0 .6rem 1.5rem; color: var(--text); }
li { margin: .25rem 0; }

/* ── STEP ─────────────────────────────────────────────────────────────────── */
.step { display: flex; gap: 1.4rem; margin: 2rem 0; }
.step-num {
  flex-shrink: 0; width: 2.2rem; height: 2.2rem; border-radius: 50%;
  background: rgba(167,139,250,.1);
  border: 1px solid rgba(167,139,250,.4);
  color: var(--violet); font-family: var(--mono); font-size: .85rem;
  display: flex; align-items: center; justify-content: center; font-weight: 600;
  margin-top: .1rem;
  box-shadow: 0 0 12px rgba(167,139,250,.12);
}
.step-body h3 { margin-top: 0; }

/* ── CALLOUT ──────────────────────────────────────────────────────────────── */
.callout {
  border-left: 3px solid var(--violet); border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1rem 1.1rem; margin: 1.4rem 0;
  background: linear-gradient(90deg, rgba(167,139,250,.06), transparent 80%);
}
.callout.info { border-color: var(--sky); background: linear-gradient(90deg, var(--sky-dim), transparent 80%); }
.callout.tip { border-color: var(--green); background: linear-gradient(90deg, var(--green-dim), transparent 80%); }
.callout.warn { border-color: var(--amber); background: linear-gradient(90deg, rgba(251,191,36,.06), transparent 80%); }
.callout-title { font-family: var(--mono); font-size: .73rem; letter-spacing: .12em; text-transform: uppercase; margin-bottom: .45rem; font-weight: 600; }
.callout.info .callout-title { color: var(--sky); }
.callout.tip  .callout-title { color: var(--green); }
.callout.warn .callout-title { color: var(--amber); }
.callout      .callout-title { color: var(--violet); }
.callout p { font-size: .9rem; color: var(--muted); margin: .3rem 0; }

/* ── TABLE ────────────────────────────────────────────────────────────────── */
table { width: 100%; border-collapse: collapse; font-size: .88rem; margin: 1.1rem 0; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
th { font-family: var(--mono); font-size: .72rem; color: var(--text); letter-spacing: .12em; text-transform: uppercase; background: var(--panel-lit); border-bottom: 1px solid var(--border); padding: .55rem .85rem; text-align: left; }
td { border-bottom: 1px solid rgba(28,40,64,.6); padding: .5rem .85rem; color: var(--text); }
td:first-child { font-family: var(--mono); font-size: .82rem; color: var(--amber); }
tr:last-child td { border-bottom: none; }
tr:hover td { background: rgba(167,139,250,.04); }

/* ── FOOTER (doc pages) ──────────────────────────────────────────────────── */
footer { border-top: 1px solid var(--border); padding: 2rem 1.75rem; font-family: var(--mono); font-size: .78rem; color: var(--muted); }
footer a { color: var(--muted); text-decoration: none; transition: color .15s; }
footer a:hover { color: var(--violet); }

@media (max-width: 768px) {
  .layout { grid-template-columns: 1fr; }
  .toc { display: none; }
  article { padding: 2rem 1.25rem; }
  .dm-links { display: none; }
}