:root {
  --bg: #0a1014;
  --panel: rgba(15, 22, 28, 0.82);
  --panel-solid: #171d22;
  --border: rgba(255, 255, 255, 0.12);
  --text: #e8ece9;
  --muted: #9aadb8;
  --accent: #00c2a8;
  --accent-dim: rgba(10, 74, 66, 0.72);
  --danger: #e05252;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background: url("/splash.png") center / cover no-repeat;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(ellipse 80% 60% at 50% 20%, rgba(0, 0, 0, 0.25) 0%, rgba(0, 0, 0, 0.55) 100%),
    linear-gradient(180deg, rgba(6, 12, 16, 0.55) 0%, rgba(6, 12, 16, 0.82) 100%);
}

.manual-header {
  border-bottom: 1px solid var(--border);
  background: var(--panel);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 16px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  position: sticky;
  top: 0;
  z-index: 10;
}

.manual-header h1 {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 700;
}

.manual-header a {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.95rem;
}

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

.manual-header-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
}

.lang-switch {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.lang-btn {
  background: rgba(10, 16, 20, 0.65);
  border: none;
  color: var(--muted);
  padding: 7px 14px;
  cursor: pointer;
  font-size: 0.85rem;
  font-family: inherit;
  line-height: 1.2;
}

.lang-btn:hover {
  color: var(--text);
  background: rgba(23, 29, 34, 0.9);
}

.lang-btn.active {
  background: var(--accent);
  color: #06231d;
  font-weight: 700;
}

.lang-btn + .lang-btn {
  border-left: 1px solid var(--border);
}

.manual-footer {
  margin-top: 32px;
  color: var(--muted);
  font-size: 0.88rem;
}

.manual-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 0;
  max-width: 1100px;
  margin: 0 auto;
  background: var(--panel);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
  min-height: calc(100vh - 57px);
}

@media (max-width: 800px) {
  .manual-layout {
    grid-template-columns: 1fr;
  }
  .manual-toc {
    position: static;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
}

.manual-toc {
  padding: 20px 16px 32px;
  border-right: 1px solid var(--border);
  position: sticky;
  top: 57px;
  align-self: start;
  max-height: calc(100vh - 57px);
  overflow-y: auto;
}

.manual-toc p {
  margin: 0 0 8px;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.manual-toc ul {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
}

.manual-toc li {
  margin: 0 0 4px;
}

.manual-toc a {
  display: block;
  padding: 4px 8px;
  border-radius: 6px;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.88rem;
}

.manual-toc a:hover,
.manual-toc a:focus {
  color: var(--text);
  background: var(--panel);
}

.manual-content {
  padding: 24px 28px 48px;
  min-width: 0;
}

.manual-content h2 {
  margin: 32px 0 12px;
  font-size: 1.35rem;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}

.manual-content h2:first-child {
  margin-top: 0;
  border-top: none;
  padding-top: 0;
}

.manual-content h3 {
  margin: 20px 0 8px;
  font-size: 1.05rem;
  color: var(--accent);
}

.manual-content p,
.manual-content li {
  color: var(--text);
  font-size: 0.95rem;
}

.manual-content ul,
.manual-content ol {
  margin: 8px 0 12px;
  padding-left: 1.4rem;
}

.manual-content li {
  margin-bottom: 4px;
}

.manual-content code {
  background: rgba(10, 16, 20, 0.65);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 0.88em;
}

.manual-intro {
  color: var(--muted);
  font-size: 1rem;
  margin: 0 0 20px;
}

.manual-note {
  background: var(--accent-dim);
  border: 1px solid var(--accent);
  border-radius: 8px;
  padding: 12px 14px;
  margin: 12px 0;
  font-size: 0.92rem;
}

.manual-note strong {
  color: var(--accent);
}

.manual-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin: 12px 0 16px;
}

.manual-table th,
.manual-table td {
  border: 1px solid var(--border);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

.manual-table th {
  background: rgba(10, 16, 20, 0.55);
  color: var(--muted);
  font-weight: 600;
}

.manual-table td code {
  border: none;
  padding: 0;
  background: transparent;
}

.manual-diagram {
  background: rgba(10, 16, 20, 0.55);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  font-family: ui-monospace, Consolas, monospace;
  font-size: 0.82rem;
  line-height: 1.45;
  overflow-x: auto;
  white-space: pre;
  color: var(--muted);
}