/* ===========================================================================
   I2RT Documentation — stylesheet
   =========================================================================== */
:root {
  --bg:            #0d1117;
  --bg-soft:       #11161d;
  --bg-panel:      #161b22;
  --bg-elevated:   #1c2330;
  --border:        #232b36;
  --border-soft:   #1b222c;
  --text:          #d7dee8;
  --text-soft:     #9aa7b6;
  --text-faint:    #6b7888;
  --accent:        #00b8a9;
  --accent-2:      #4f9cf9;
  --accent-warm:   #f5a623;
  --danger:        #f97583;
  --green:         #5dd39e;
  --purple:        #b392f0;
  --code-bg:       #0a0e14;
  --radius:        10px;
  --sidebar-w:     290px;
  --toc-w:         220px;
  --maxw:          860px;
  --mono: "SFMono-Regular", "JetBrains Mono", Consolas, "Liberation Mono", Menlo, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
:root[data-theme="light"] {
  --bg:            #ffffff;
  --bg-soft:       #f6f8fa;
  --bg-panel:      #ffffff;
  --bg-elevated:   #f0f3f6;
  --border:        #d6dde5;
  --border-soft:   #e6eaef;
  --text:          #1f2733;
  --text-soft:     #56657a;
  --text-faint:    #8593a4;
  --accent:        #008e82;
  --accent-2:      #2563eb;
  --code-bg:       #f6f8fa;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  margin: 0;
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Layout ---------- */
.layout { display: flex; min-height: 100vh; }
.content-wrap {
  flex: 1;
  min-width: 0;
  display: flex;
  justify-content: center;
  padding: 0 40px;
}
main {
  max-width: var(--maxw);
  width: 100%;
  padding: 48px 0 120px;
}

/* ---------- Sidebar ---------- */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--bg-soft);
  border-right: 1px solid var(--border);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 22px 0 60px;
}
.sidebar .brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 22px 18px;
  border-bottom: 1px solid var(--border-soft);
  margin-bottom: 14px;
}
.brand .logo {
  width: 38px; height: 38px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: grid; place-items: center;
  font-weight: 800; color: #fff; font-size: 17px;
  letter-spacing: -0.5px;
  flex-shrink: 0;
}
.brand .brand-text strong { display:block; font-size: 15px; letter-spacing: -0.2px; }
.brand .brand-text span { font-size: 12px; color: var(--text-faint); }

.nav-search {
  margin: 0 18px 16px;
}
.nav-search input {
  width: 100%;
  padding: 8px 12px;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 13px;
  font-family: var(--sans);
}
.nav-search input:focus { outline: none; border-color: var(--accent); }

.nav-group { margin-bottom: 6px; }
.nav-group > .nav-title {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--text-faint);
  font-weight: 700;
  padding: 12px 22px 6px;
}
.sidebar a {
  display: block;
  padding: 6px 22px 6px 22px;
  color: var(--text-soft);
  text-decoration: none;
  font-size: 14px;
  border-left: 2px solid transparent;
  transition: color .12s, background .12s;
}
.sidebar a:hover { color: var(--text); background: var(--bg-elevated); }
.sidebar a.active {
  color: var(--accent);
  border-left-color: var(--accent);
  background: linear-gradient(90deg, color-mix(in srgb, var(--accent) 10%, transparent), transparent);
  font-weight: 600;
}

/* ---------- TOC (right) ---------- */
.toc {
  width: var(--toc-w);
  flex-shrink: 0;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 52px 22px;
  font-size: 13px;
}
.toc .toc-title {
  text-transform: uppercase;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-faint);
  font-weight: 700;
  margin-bottom: 10px;
}
.toc a {
  display: block;
  color: var(--text-faint);
  text-decoration: none;
  padding: 3px 0 3px 12px;
  border-left: 2px solid var(--border);
  line-height: 1.4;
}
.toc a:hover { color: var(--text); }
.toc a.active { color: var(--accent); border-left-color: var(--accent); }
.toc a.lvl3 { padding-left: 26px; font-size: 12px; }

/* ---------- Topbar (mobile) ---------- */
.topbar {
  display: none;
  position: sticky; top: 0; z-index: 40;
  align-items: center; gap: 14px;
  padding: 12px 18px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
}
.topbar button {
  background: var(--bg-panel); border: 1px solid var(--border);
  color: var(--text); border-radius: 8px; padding: 6px 10px;
  cursor: pointer; font-size: 18px; line-height: 1;
}
.theme-toggle {
  background: var(--bg-panel); border: 1px solid var(--border);
  color: var(--text-soft); border-radius: 8px; padding: 6px 10px;
  cursor: pointer; font-size: 13px; margin: 0 18px 4px;
  width: calc(100% - 36px);
}
.theme-toggle:hover { color: var(--text); border-color: var(--accent); }

/* ---------- Typography ---------- */
h1, h2, h3, h4 { line-height: 1.25; font-weight: 700; letter-spacing: -0.3px; scroll-margin-top: 80px; }
h1 { font-size: 2.3rem; margin: 0 0 6px; }
h2 {
  font-size: 1.6rem; margin: 56px 0 18px;
  padding-bottom: 10px; border-bottom: 1px solid var(--border);
}
h3 { font-size: 1.22rem; margin: 36px 0 12px; color: var(--text); }
h4 { font-size: 1.02rem; margin: 24px 0 8px; color: var(--text-soft); }
p { margin: 14px 0; color: var(--text); }
a { color: var(--accent-2); }
ul, ol { padding-left: 24px; }
li { margin: 6px 0; }
strong { color: var(--text); font-weight: 650; }
hr { border: none; border-top: 1px solid var(--border); margin: 40px 0; }
.lead { font-size: 1.12rem; color: var(--text-soft); margin: 16px 0 28px; }
.eyebrow {
  display:inline-block; font-size: 12px; font-weight: 700; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 12px;
}

/* ---------- Code ---------- */
code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--bg-elevated);
  padding: 2px 6px;
  border-radius: 5px;
  color: var(--purple);
  border: 1px solid var(--border-soft);
}
pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  overflow-x: auto;
  margin: 18px 0;
  position: relative;
}
pre code {
  background: none; border: none; padding: 0; color: var(--text);
  font-size: 13.5px; line-height: 1.6;
}
.code-label {
  display: inline-block;
  font-family: var(--mono); font-size: 11px;
  color: var(--text-faint);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-bottom: none;
  border-radius: 8px 8px 0 0;
  padding: 4px 12px;
  margin: 18px 0 -18px;
  position: relative; top: 9px;
}
.code-label + pre { border-top-left-radius: 0; }

/* simple token coloring */
.tok-kw { color: #ff7b72; }
.tok-str { color: #a5d6ff; }
.tok-com { color: #6b7888; font-style: italic; }
.tok-fn { color: #d2a8ff; }
.tok-num { color: #79c0ff; }

/* ---------- Callouts ---------- */
.callout {
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  background: var(--bg-panel);
  border-radius: 8px;
  padding: 14px 18px;
  margin: 20px 0;
  font-size: 0.96rem;
}
.callout .callout-title { font-weight: 700; margin-bottom: 4px; display:flex; gap:8px; align-items:center; }
.callout.warn { border-left-color: var(--accent-warm); }
.callout.warn .callout-title { color: var(--accent-warm); }
.callout.danger { border-left-color: var(--danger); }
.callout.danger .callout-title { color: var(--danger); }
.callout.tip { border-left-color: var(--green); }
.callout.tip .callout-title { color: var(--green); }
.callout p:first-child { margin-top: 0; }
.callout p:last-child { margin-bottom: 0; }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; margin: 20px 0; }
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 14px;
}
th, td {
  border: 1px solid var(--border);
  padding: 9px 13px;
  text-align: left;
  vertical-align: top;
}
th { background: var(--bg-elevated); font-weight: 650; color: var(--text); }
tr:nth-child(even) td { background: var(--bg-soft); }
td code { font-size: 0.82em; white-space: nowrap; }

/* ---------- Cards ---------- */
.card-grid { display: grid; gap: 16px; margin: 22px 0; }
.card-grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.card-grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.card {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  transition: border-color .15s, transform .15s;
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card h4 { margin: 0 0 6px; color: var(--text); }
.card .ico { font-size: 22px; margin-bottom: 8px; }
.card p { margin: 0; font-size: 0.9rem; color: var(--text-soft); }
.card a { text-decoration: none; }

/* ---------- Hero ---------- */
.hero {
  border: 1px solid var(--border);
  border-radius: 16px;
  background:
    radial-gradient(1100px 320px at 10% -20%, color-mix(in srgb, var(--accent) 16%, transparent), transparent),
    radial-gradient(900px 300px at 90% 0%, color-mix(in srgb, var(--accent-2) 14%, transparent), transparent),
    var(--bg-panel);
  padding: 40px 38px;
  margin-bottom: 26px;
}
.hero h1 { font-size: 2.6rem; }
.badges { display:flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.badge {
  font-size: 12px; font-family: var(--mono);
  padding: 4px 10px; border-radius: 20px;
  background: var(--bg-elevated); border: 1px solid var(--border);
  color: var(--text-soft);
}
.badge b { color: var(--accent); }

/* ---------- Pills / chips ---------- */
.pill {
  display:inline-block; font-size: 12px; font-weight: 600;
  padding: 2px 9px; border-radius: 20px;
  border: 1px solid var(--border);
}
.pill.real { color: var(--green); border-color: color-mix(in srgb, var(--green) 50%, var(--border)); }
.pill.sim  { color: var(--accent-2); border-color: color-mix(in srgb, var(--accent-2) 50%, var(--border)); }

/* ---------- Diagram (ASCII / flow) ---------- */
.diagram {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  margin: 22px 0;
  font-family: var(--mono);
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--text-soft);
  overflow-x: auto;
  white-space: pre;
}
.layer-stack { display: flex; flex-direction: column; gap: 0; margin: 22px 0; }
.layer {
  border: 1px solid var(--border);
  padding: 14px 18px;
  background: var(--bg-panel);
  position: relative;
}
.layer:first-child { border-radius: 10px 10px 0 0; }
.layer:last-child { border-radius: 0 0 10px 10px; }
.layer + .layer { border-top: none; }
.layer .l-tag {
  font-family: var(--mono); font-size: 11px; color: var(--accent);
  text-transform: uppercase; letter-spacing: .06em;
}
.layer h4 { margin: 2px 0 4px; }
.layer p { margin: 0; font-size: 0.88rem; color: var(--text-soft); }
.layer.accent2 .l-tag { color: var(--accent-2); }
.layer.warm .l-tag { color: var(--accent-warm); }
.layer.purple .l-tag { color: var(--purple); }

footer.docfoot {
  margin-top: 70px; padding-top: 26px;
  border-top: 1px solid var(--border);
  color: var(--text-faint); font-size: 14px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
}
.kbd {
  font-family: var(--mono); font-size: 11px;
  background: var(--bg-elevated); border: 1px solid var(--border);
  border-bottom-width: 2px; border-radius: 5px; padding: 1px 6px;
}

/* ---------- Responsive ---------- */
@media (max-width: 1180px) {
  .toc { display: none; }
}
@media (max-width: 900px) {
  .topbar { display: flex; }
  .sidebar {
    position: fixed; z-index: 60; top: 0; left: 0;
    transform: translateX(-100%); transition: transform .22s ease;
    box-shadow: 0 0 50px rgba(0,0,0,.5);
  }
  .sidebar.open { transform: translateX(0); }
  .content-wrap { padding: 0 18px; }
  main { padding: 26px 0 80px; }
  .card-grid.cols-2, .card-grid.cols-3 { grid-template-columns: 1fr; }
  .hero { padding: 28px 22px; }
  .hero h1 { font-size: 2rem; }
  h1 { font-size: 1.8rem; }
  .scrim { display:none; position: fixed; inset: 0; background: rgba(0,0,0,.5); z-index: 55; }
  .scrim.show { display: block; }
}