.manual-header {
  border-bottom: 1px solid var(--border);
  background:
    radial-gradient(800px 280px at 50% -120px, color-mix(in srgb, var(--brand) 28%, transparent), transparent 65%),
    var(--bg);
}

.manual-header-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 12px;
  padding: 16px 0;
}

.manual-home-btn {
  justify-self: start;
  text-decoration: none;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  background: var(--card);
}

.manual-title {
  justify-self: center;
  font-size: clamp(1.1rem, 1.8vw, 1.35rem);
  font-weight: 700;
}

.manual-language-control {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.92rem;
  color: var(--muted);
}

.manual-language-control select {
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--card);
  color: var(--text);
  padding: 6px 10px;
}

.manual-layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 24px;
  padding: 24px 16px 40px;
}

.manual-toc {
  position: sticky;
  top: 16px;
  max-height: calc(100vh - 32px);
  overflow: auto;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: var(--card);
  padding: 16px;
}

.manual-toc h2 {
  margin: 0 0 12px;
  font-size: 1rem;
}

.manual-toc a {
  display: block;
  color: var(--text);
  text-decoration: none;
  padding: 6px 8px;
  border-radius: 8px;
  margin: 2px 0;
}

.manual-toc a.level-2 { padding-left: 16px; }
.manual-toc a.level-3 { padding-left: 24px; }
.manual-toc a.active { background: color-mix(in srgb, var(--brand) 14%, transparent); }

.manual-content {
  border: 1px solid var(--border);
  border-radius: 16px;
  background: var(--card);
  padding: 24px;
}

.manual-content h1, .manual-content h2, .manual-content h3 {
  scroll-margin-top: 16px;
}

.manual-content code {
  background: color-mix(in srgb, var(--border) 45%, transparent);
  padding: 2px 6px;
  border-radius: 6px;
}

.manual-content pre {
  background: #0b1020;
  color: #f4f7ff;
  padding: 12px;
  border-radius: 10px;
  overflow: auto;
}

.manual-content img {
  display: block;
  width: 100%;
  max-width: 960px;
  height: auto;
  margin: 14px 0 18px;
  border: 1px solid var(--border);
  border-radius: 12px;
}

@media (max-width: 900px) {
  .manual-header-row {
    grid-template-columns: 1fr;
    justify-items: center;
  }

  .manual-home-btn,
  .manual-language-control,
  .manual-title {
    justify-self: center;
  }

  .manual-layout {
    grid-template-columns: 1fr;
  }

  .manual-toc {
    position: static;
    max-height: none;
  }
}