/* ═══════════════════════════════════════════════════════════════
   layer docs — Professional Theme
   ═══════════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* ── Root variables ─────────────────────────────────────────── */
:root {
  --layer-accent:       #7c6af7;
  --layer-accent-light: #a89ef9;
  --layer-accent-glow:  rgba(124,106,247,0.18);
  --layer-green:        #22c55e;
  --layer-red:          #ef4444;
  --layer-yellow:       #f59e0b;
  --layer-blue:         #3b82f6;
  --layer-cyan:         #06b6d4;
  --layer-orange:       #f97316;
  --radius:             10px;
  --radius-sm:          6px;
  --shadow:             0 4px 24px rgba(0,0,0,0.28);
  --shadow-sm:          0 2px 8px rgba(0,0,0,0.18);
}

/* ── Base typography ─────────────────────────────────────────── */
body { font-family: 'Inter', system-ui, sans-serif !important; }
code, pre, .hljs { font-family: 'JetBrains Mono', 'Fira Code', monospace !important; }

.content main {
  max-width: 860px;
  line-height: 1.78;
  font-size: 1.01rem;
}

/* ── Sidebar ─────────────────────────────────────────────────── */
.sidebar {
  background: #0f1117 !important;
  border-right: 1px solid rgba(124,106,247,0.15) !important;
}
.sidebar .sidebar-scrollbox { padding-top: 0 !important; }

/* Sidebar top brand */
.sidebar-scrollbox::before {
  content: "⚡ layer";
  display: block;
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #fff;
  padding: 22px 20px 6px;
  background: linear-gradient(135deg, var(--layer-accent), var(--layer-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.sidebar-scrollbox::after {
  content: "Telegram MTProto · Rust";
  display: block;
  font-size: 0.7rem;
  font-weight: 500;
  color: rgba(255,255,255,0.35);
  padding: 0 20px 18px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  border-bottom: 1px solid rgba(255,255,255,0.07);
  margin-bottom: 10px;
}

.chapter li a {
  border-radius: var(--radius-sm);
  transition: background 0.15s, color 0.15s;
  padding: 5px 12px !important;
  margin: 1px 8px !important;
  font-size: 0.88rem;
}
.chapter li a:hover {
  background: rgba(124,106,247,0.12) !important;
  color: var(--layer-accent-light) !important;
}
.chapter li a.active {
  background: rgba(124,106,247,0.22) !important;
  color: #fff !important;
  font-weight: 600;
  border-left: 3px solid var(--layer-accent);
}

/* Section labels */
.chapter li.part-title {
  font-size: 0.68rem !important;
  letter-spacing: 0.1em !important;
  text-transform: uppercase !important;
  color: rgba(255,255,255,0.3) !important;
  padding: 16px 20px 4px !important;
  font-weight: 600 !important;
}

/* ── Page header hero ────────────────────────────────────────── */
h1:first-of-type {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 0.3em;
  background: linear-gradient(135deg, #fff 30%, var(--layer-accent-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: 1.45rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  margin-top: 2.4em;
  margin-bottom: 0.6em;
  padding-bottom: 0.4em;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  color: #e2e8f0;
}

h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--layer-accent-light);
  margin-top: 1.8em;
}

h4 {
  font-size: 0.95rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: rgba(255,255,255,0.5);
  margin-top: 1.4em;
}

/* ── Code blocks ─────────────────────────────────────────────── */
pre {
  border-radius: var(--radius) !important;
  border: 1px solid rgba(255,255,255,0.07) !important;
  box-shadow: var(--shadow) !important;
  position: relative;
  overflow: hidden;
}

pre::before {
  content: '';
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--layer-accent), var(--layer-cyan));
  position: absolute;
  top: 0; left: 0; right: 0;
}

pre code {
  font-size: 0.865rem !important;
  line-height: 1.7 !important;
}

/* Language label */
pre[class*="language-"]::after,
code[class*="language-"]::before {
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.25);
  position: absolute;
  top: 14px; right: 16px;
}

/* Inline code */
code:not(pre code) {
  background: rgba(124,106,247,0.12) !important;
  border: 1px solid rgba(124,106,247,0.2) !important;
  color: var(--layer-accent-light) !important;
  border-radius: var(--radius-sm) !important;
  padding: 2px 7px !important;
  font-size: 0.87em !important;
  font-weight: 500 !important;
}

/* ── Tables ──────────────────────────────────────────────────── */
table {
  border-collapse: collapse !important;
  width: 100% !important;
  border-radius: var(--radius) !important;
  overflow: hidden !important;
  box-shadow: var(--shadow-sm) !important;
  font-size: 0.9rem !important;
  margin: 1.5em 0 !important;
}

table thead tr {
  background: linear-gradient(135deg, rgba(124,106,247,0.25), rgba(6,182,212,0.12)) !important;
}

table thead th {
  padding: 12px 18px !important;
  font-weight: 600 !important;
  font-size: 0.82rem !important;
  letter-spacing: 0.04em !important;
  text-transform: uppercase !important;
  color: rgba(255,255,255,0.75) !important;
  border-bottom: 1px solid rgba(124,106,247,0.25) !important;
  border-right: none !important;
}

table tbody tr {
  border-bottom: 1px solid rgba(255,255,255,0.05) !important;
  transition: background 0.12s !important;
}
table tbody tr:hover {
  background: rgba(124,106,247,0.06) !important;
}
table tbody td {
  padding: 11px 18px !important;
  border-right: none !important;
  vertical-align: middle !important;
}
table tbody tr:last-child { border-bottom: none !important; }

/* ── Callout boxes ───────────────────────────────────────────── */
.callout {
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 1.4em 0;
  border-left: 4px solid;
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 0.92rem;
  line-height: 1.65;
}
.callout-icon { font-size: 1.1rem; margin-top: 1px; flex-shrink: 0; }
.callout-content { flex: 1; }
.callout-content strong { display: block; margin-bottom: 4px; font-size: 0.9rem; letter-spacing: 0.02em; }

.callout-info    { background: rgba(59,130,246,0.1);  border-color: var(--layer-blue); }
.callout-info    .callout-icon { color: var(--layer-blue); }
.callout-info    strong { color: var(--layer-blue); }

.callout-tip     { background: rgba(34,197,94,0.1);   border-color: var(--layer-green); }
.callout-tip     .callout-icon { color: var(--layer-green); }
.callout-tip     strong { color: var(--layer-green); }

.callout-warning { background: rgba(245,158,11,0.1);  border-color: var(--layer-yellow); }
.callout-warning .callout-icon { color: var(--layer-yellow); }
.callout-warning strong { color: var(--layer-yellow); }

.callout-danger  { background: rgba(239,68,68,0.1);   border-color: var(--layer-red); }
.callout-danger  .callout-icon { color: var(--layer-red); }
.callout-danger  strong { color: var(--layer-red); }

.callout-note    { background: rgba(124,106,247,0.1); border-color: var(--layer-accent); }
.callout-note    .callout-icon { color: var(--layer-accent); }
.callout-note    strong { color: var(--layer-accent-light); }

/* mdBook blockquote → styled callout */
blockquote {
  border-radius: var(--radius) !important;
  border-left: 4px solid var(--layer-accent) !important;
  background: rgba(124,106,247,0.08) !important;
  padding: 14px 18px !important;
  margin: 1.4em 0 !important;
  color: rgba(255,255,255,0.8) !important;
  font-size: 0.93rem !important;
}
blockquote p { margin: 0 !important; }

/* ── Feature grid ────────────────────────────────────────────── */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  margin: 1.5em 0;
}
.feature-card {
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: var(--radius);
  padding: 18px 20px;
  transition: border-color 0.2s, background 0.2s, transform 0.15s;
}
.feature-card:hover {
  border-color: rgba(124,106,247,0.4);
  background: rgba(124,106,247,0.06);
  transform: translateY(-2px);
}
.feature-card .fc-icon { font-size: 1.5rem; margin-bottom: 10px; }
.feature-card .fc-title { font-weight: 600; font-size: 0.93rem; color: #e2e8f0; margin-bottom: 5px; }
.feature-card .fc-desc  { font-size: 0.82rem; color: rgba(255,255,255,0.5); line-height: 1.55; }

/* ── API signature cards ─────────────────────────────────────── */
.api-card {
  background: rgba(255,255,255,0.025);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: var(--radius);
  margin: 1.2em 0;
  overflow: hidden;
}
.api-card-header {
  background: rgba(124,106,247,0.12);
  border-bottom: 1px solid rgba(124,106,247,0.18);
  padding: 10px 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.api-badge {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 4px;
}
.api-badge-async { background: rgba(34,197,94,0.2); color: var(--layer-green); }
.api-badge-fn    { background: rgba(59,130,246,0.2); color: var(--layer-blue); }
.api-badge-type  { background: rgba(249,115,22,0.2); color: var(--layer-orange); }
.api-card-sig    { font-family: 'JetBrains Mono', monospace; font-size: 0.84rem; color: #e2e8f0; }
.api-card-body   { padding: 14px 16px; font-size: 0.9rem; color: rgba(255,255,255,0.72); line-height: 1.65; }

/* ── Badges / pills ──────────────────────────────────────────── */
.badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  padding: 2px 9px;
  border-radius: 999px;
  vertical-align: middle;
  margin: 0 2px;
  text-transform: uppercase;
}
.badge-default  { background: rgba(124,106,247,0.2); color: var(--layer-accent-light); }
.badge-optional { background: rgba(255,255,255,0.08); color: rgba(255,255,255,0.5); }
.badge-required { background: rgba(239,68,68,0.18); color: #fca5a5; }
.badge-new      { background: rgba(34,197,94,0.18); color: #86efac; }
.badge-bot      { background: rgba(6,182,212,0.18); color: #67e8f9; }
.badge-user     { background: rgba(249,115,22,0.18); color: #fdba74; }

/* ── Hero banner on intro page ───────────────────────────────── */
.hero-banner {
  background: linear-gradient(135deg, rgba(124,106,247,0.15) 0%, rgba(6,182,212,0.08) 100%);
  border: 1px solid rgba(124,106,247,0.2);
  border-radius: 14px;
  padding: 32px 36px;
  margin: 1em 0 2em;
  text-align: center;
}
.hero-banner h2 {
  border: none !important;
  font-size: 1.2rem !important;
  color: rgba(255,255,255,0.6) !important;
  font-weight: 400 !important;
  margin: 0.3em 0 1em !important;
  letter-spacing: 0 !important;
  text-transform: none !important;
}
.hero-badges { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-top: 12px; }
.hero-badges img { height: 22px; border-radius: 4px; }

/* ── Divider ─────────────────────────────────────────────────── */
hr {
  border: none !important;
  height: 1px !important;
  background: linear-gradient(90deg, transparent, rgba(124,106,247,0.3), transparent) !important;
  margin: 2.5em 0 !important;
}

/* ── Scrollbar ───────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(124,106,247,0.35); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(124,106,247,0.6); }

/* ── Nav buttons ─────────────────────────────────────────────── */
.nav-chapters .fa {
  background: rgba(124,106,247,0.15);
  border-radius: 50%;
  padding: 12px;
  transition: background 0.2s;
}
.nav-chapters .fa:hover { background: rgba(124,106,247,0.3); }

/* ── Top menu bar ────────────────────────────────────────────── */
#menu-bar {
  background: rgba(10,12,20,0.95) !important;
  backdrop-filter: blur(12px) !important;
  border-bottom: 1px solid rgba(124,106,247,0.12) !important;
}
#menu-bar i { color: rgba(255,255,255,0.6) !important; }
#menu-bar i:hover { color: var(--layer-accent-light) !important; }

/* ── Search ──────────────────────────────────────────────────── */
#searchbar {
  border-radius: var(--radius-sm) !important;
  border: 1px solid rgba(124,106,247,0.25) !important;
  background: rgba(255,255,255,0.05) !important;
  color: #fff !important;
  font-family: 'Inter', sans-serif !important;
}
#searchbar:focus {
  border-color: var(--layer-accent) !important;
  box-shadow: 0 0 0 3px var(--layer-accent-glow) !important;
  outline: none !important;
}

/* ── Selection ───────────────────────────────────────────────── */
::selection { background: rgba(124,106,247,0.35); }

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 600px) {
  h1:first-of-type { font-size: 1.6rem; }
  .feature-grid { grid-template-columns: 1fr; }
  .hero-banner { padding: 20px; }
}