/* ============================================================
   Lab coin — Музикално дистанционно управление
   Ръководство — стилове (черно/бяло)
   ============================================================ */

:root {
  --bg: #ffffff;
  --fg: #000000;
  --muted: #555555;
  --faint: #777777;
  --line: #000000;
  --line-soft: #e0e0e0;
  --fill: #f4f4f4;
  --maxw: 820px;
  font-size: 16px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Hero ---------- */
.hero {
  padding: 80px 24px 56px;
  text-align: center;
  border-bottom: 2px solid var(--line);
}

.hero-inner {
  max-width: var(--maxw);
  margin: 0 auto;
}

.brand-mark {
  display: inline-block;
  font-weight: 700;
  letter-spacing: 1.5px;
  font-size: 0.78rem;
  text-transform: uppercase;
  padding: 7px 16px;
  border: 2px solid var(--fg);
  background: var(--fg);
  color: var(--bg);
}

.hero h1 {
  margin: 26px 0 14px;
  font-size: clamp(1.9rem, 5vw, 3rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--fg);
}

.subtitle {
  color: var(--muted);
  font-size: 1.08rem;
  max-width: 560px;
  margin: 0 auto;
}

/* ---------- Sticky TOC ---------- */
.toc {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}

.toc-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  padding: 0 24px;
}

.toc a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  padding: 14px 16px;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.toc a:hover {
  color: var(--fg);
  border-bottom-color: var(--fg);
}

/* ---------- Layout ---------- */
.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 48px 24px 24px;
}

.section {
  border-top: 1px solid var(--line-soft);
  padding: 44px 0 8px;
  scroll-margin-top: 64px;
}

.section:first-child {
  border-top: none;
}

.section-number {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--fg);
  border: 1px solid var(--fg);
  padding: 3px 10px;
  margin-bottom: 16px;
}

h2 {
  font-size: clamp(1.4rem, 3.5vw, 1.9rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 22px;
  line-height: 1.18;
}

h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 32px 0 12px;
  color: var(--fg);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line-soft);
}

p {
  color: var(--muted);
  margin-bottom: 12px;
}

strong { color: var(--fg); font-weight: 700; }
em { color: var(--fg); font-style: italic; }

/* ---------- Lists ---------- */
.list {
  list-style: none;
  margin-bottom: 12px;
}

.list li {
  position: relative;
  color: var(--muted);
  padding: 5px 0 5px 24px;
}

.list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 13px;
  width: 7px;
  height: 7px;
  background: var(--fg);
}

.list.ordered {
  counter-reset: step;
}

.list.ordered li {
  padding-left: 36px;
}

.list.ordered li::before {
  content: counter(step);
  counter-increment: step;
  top: 6px;
  left: 0;
  width: 24px;
  height: 24px;
  background: transparent;
  border: 1.5px solid var(--fg);
  border-radius: 50%;
  color: var(--fg);
  font-size: 0.78rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ---------- Spec grid ---------- */
.spec-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  margin-top: 22px;
  border: 1px solid var(--line);
}

.spec-card {
  padding: 22px 18px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-right: 1px solid var(--line-soft);
}

.spec-card:last-child {
  border-right: none;
}

.spec-value {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--fg);
}

.spec-label {
  font-size: 0.85rem;
  color: var(--faint);
}

/* ---------- Points table ---------- */
.points-table {
  width: 100%;
  border-collapse: collapse;
  margin: 8px 0 4px;
  border: 1px solid var(--line);
}

.points-table th,
.points-table td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--line-soft);
  color: var(--muted);
  vertical-align: middle;
}

.points-table thead th {
  background: var(--fg);
  color: var(--bg);
  font-size: 0.78rem;
  letter-spacing: 0.6px;
  text-transform: uppercase;
  border-bottom: none;
}

.points-table tbody tr:last-child td {
  border-bottom: none;
}

.points-table td:first-child,
.points-table th:first-child {
  text-align: center;
  white-space: nowrap;
}

.btn-token {
  display: inline-block;
  font-weight: 700;
  color: var(--fg);
  background: var(--bg);
  border: 1.5px solid var(--fg);
  padding: 3px 11px;
  font-size: 0.95rem;
  letter-spacing: 1px;
}

/* ---------- Callouts ---------- */
.callout {
  padding: 16px 18px;
  margin: 18px 0;
  border: 1px solid var(--line);
  border-left-width: 5px;
  background: var(--bg);
}

.callout p { color: var(--fg); margin-bottom: 8px; }
.callout p:last-child { margin-bottom: 0; }
.callout .list { margin-top: 8px; margin-bottom: 0; }

.callout.info    { background: var(--fill); }
.callout.success { background: var(--bg); }
.callout.warning { background: var(--fill); border-left-style: solid; }

.callout-head {
  display: flex;
  align-items: flex-start;
  gap: 11px;
}

.callout-head .ico {
  flex: none;
  width: 19px;
  height: 19px;
  margin-top: 3px;
}

/* ---------- Contact ---------- */
.contact-card {
  display: flex;
  flex-direction: column;
  gap: 4px;
  text-decoration: none;
  border: 2px solid var(--fg);
  padding: 18px 22px;
  margin: 18px 0 14px;
  transition: background 0.15s, color 0.15s;
}

.contact-card:hover {
  background: var(--fg);
}

.contact-card:hover .contact-label,
.contact-card:hover .contact-value {
  color: var(--bg);
}

.contact-label {
  font-size: 0.78rem;
  letter-spacing: 0.6px;
  text-transform: uppercase;
  color: var(--faint);
}

.contact-value {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--fg);
}

.contact-note {
  color: var(--faint);
  font-size: 0.95rem;
}

/* ---------- Footer ---------- */
.footer {
  text-align: center;
  padding: 40px 24px 56px;
  border-top: 2px solid var(--line);
  margin-top: 48px;
}

.footer p { color: var(--fg); font-weight: 700; margin-bottom: 4px; }
.footer-sub { color: var(--faint); font-weight: 500; font-size: 0.9rem; }

/* ---------- Icons ---------- */
.ico {
  display: inline-block;
  vertical-align: middle;
  stroke: currentColor;
  stroke-width: 2;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ---------- Responsive ---------- */
@media (max-width: 640px) {
  .spec-grid { grid-template-columns: 1fr; }
  .spec-card { border-right: none; border-bottom: 1px solid var(--line-soft); }
  .spec-card:last-child { border-bottom: none; }
  .hero { padding: 56px 20px 44px; }
  .points-table th, .points-table td { padding: 12px 10px; }
  .toc-inner { overflow-x: auto; flex-wrap: nowrap; }
  .toc a { white-space: nowrap; }
}