:root {
  --manual-primary: #ff6b35;
  --manual-primary-dark: #e85a28;
  --manual-secondary: #1e3a5f;
  --manual-bg: #fafafa;
  --manual-card: #ffffff;
  --manual-text: #1a1a1a;
  --manual-muted: #5c5c5c;
  --manual-border: #e8e8e8;
  --manual-radius: 12px;
  --manual-max: 52rem;
  --manual-sidebar: 16rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, Ubuntu, Cantarell, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--manual-text);
  background: var(--manual-bg);
}

.manual-header {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 1.25rem;
  background: var(--manual-secondary);
  color: #fff;
  border-bottom: 3px solid var(--manual-primary);
  flex-wrap: wrap;
}

.manual-header a {
  color: #fff;
  text-decoration: none;
  font-weight: 600;
}

.manual-header a:hover {
  text-decoration: underline;
  color: #ffdcc4;
}

.manual-nav-toggle {
  display: none;
  padding: 0.5rem 0.75rem;
  font-size: 0.9rem;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  cursor: pointer;
}

.manual-nav-toggle:hover {
  background: rgba(255, 255, 255, 0.2);
}

.manual-layout {
  display: flex;
  max-width: 1200px;
  margin: 0 auto;
  min-height: calc(100dvh - 8rem);
}

.manual-nav {
  width: var(--manual-sidebar);
  flex-shrink: 0;
  padding: 1.25rem 0 1.25rem 1rem;
  border-right: 1px solid var(--manual-border);
  background: var(--manual-card);
}

.manual-nav a {
  display: block;
  padding: 0.5rem 0.75rem;
  margin-bottom: 2px;
  border-radius: 8px;
  color: var(--manual-text);
  text-decoration: none;
  font-size: 0.92rem;
}

.manual-nav a:hover {
  background: #fff5f0;
  color: var(--manual-primary-dark);
}

.manual-nav a.is-active {
  background: linear-gradient(90deg, rgba(255, 107, 53, 0.15), transparent);
  color: var(--manual-primary-dark);
  font-weight: 600;
  border-left: 3px solid var(--manual-primary);
  padding-left: calc(0.75rem - 3px);
}

.manual-main {
  flex: 1;
  min-width: 0;
  padding: 1.5rem 1.75rem 3rem;
  max-width: var(--manual-max);
}

.manual-main h1 {
  margin: 0 0 0.5rem;
  font-size: 1.75rem;
  line-height: 1.25;
  color: var(--manual-secondary);
}

.manual-lead {
  margin: 0 0 1.5rem;
  font-size: 1.05rem;
  color: var(--manual-muted);
}

.manual-main h2 {
  margin: 2rem 0 0.75rem;
  padding-top: 0.5rem;
  font-size: 1.2rem;
  color: var(--manual-secondary);
  border-bottom: 2px solid var(--manual-primary);
  padding-bottom: 0.35rem;
}

.manual-main h3 {
  margin: 1.25rem 0 0.5rem;
  font-size: 1.05rem;
  color: var(--manual-text);
}

.manual-main p,
.manual-main li {
  color: var(--manual-muted);
}

.manual-main ul,
.manual-main ol {
  margin: 0.5rem 0 1rem 1.25rem;
  padding: 0;
}

.manual-main li + li {
  margin-top: 0.35rem;
}

.manual-note {
  margin: 1rem 0;
  padding: 0.85rem 1rem;
  border-radius: var(--manual-radius);
  background: #fff8f3;
  border: 1px solid #ffd4c0;
  font-size: 0.95rem;
  color: var(--manual-muted);
}

.manual-footer {
  margin-top: auto;
  padding: 1rem 1.5rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--manual-muted);
  border-top: 1px solid var(--manual-border);
  background: var(--manual-card);
}

.manual-toc {
  list-style: none;
  margin: 0 0 2rem;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.manual-toc li {
  list-style: none;
  margin: 0;
}

@media (min-width: 640px) {
  .manual-toc {
    grid-template-columns: repeat(2, 1fr);
  }
}

.manual-toc a {
  display: block;
  padding: 0.85rem 1rem;
  border-radius: var(--manual-radius);
  background: var(--manual-card);
  border: 1px solid var(--manual-border);
  color: var(--manual-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.manual-toc a:hover {
  border-color: var(--manual-primary);
  box-shadow: 0 4px 14px rgba(255, 107, 53, 0.12);
}

@media (max-width: 900px) {
  .manual-nav-toggle {
    display: inline-block;
  }

  .manual-layout {
    flex-direction: column;
  }

  .manual-nav {
    display: none;
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--manual-border);
    padding: 0.5rem 1rem 1rem;
  }

  .manual-nav.is-open {
    display: block;
  }

  .manual-main {
    padding: 1.25rem 1rem 2rem;
  }
}