:root {
  --bg: #f5f1ea;
  --panel: #fffdfa;
  --panel-2: #f1ece3;
  --text: #1f1d1a;
  --muted: #6b655d;
  --line: #d9d1c7;
  --accent: #6d4c41;
  --accent-soft: #ede2db;
  --shadow: 0 12px 30px rgba(0, 0, 0, 0.07);
  --radius: 18px;
  --max-width: 1500px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #f8f4ee 0%, #f1ebe2 100%);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.layout {
  display: grid;
  grid-template-columns: 290px 1fr;
  min-height: 100vh;
  max-width: var(--max-width);
  margin: 0 auto;
}

.sidebar {
  position: sticky;
  top: 0;
  align-self: start;
  height: 100vh;
  padding: 24px 18px;
  border-right: 1px solid var(--line);
  background: rgba(255, 253, 250, 0.8);
  backdrop-filter: blur(10px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}

.brand-mark {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: var(--accent-soft);
  font-size: 22px;
}

.brand-title {
  font-weight: 700;
  font-size: 1rem;
}

.brand-subtitle {
  color: var(--muted);
  font-size: 0.9rem;
}

.main-nav {
  display: grid;
  gap: 8px;
  margin-bottom: 24px;
}

.nav-link {
  padding: 12px 14px;
  border-radius: 12px;
  color: var(--text);
  background: transparent;
}

.nav-link:hover,
.nav-link.active {
  background: var(--accent-soft);
  text-decoration: none;
}

.sidebar-card,
.toc-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
}

.sidebar-card + .sidebar-card {
  margin-top: 14px;
}

.sidebar-card h3,
.toc-card h2 {
  margin-top: 0;
  font-size: 0.98rem;
}

.sidebar-card p,
.toc-card p {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.55;
}

.main-shell {
  padding: 24px;
}

.site-footer {
  margin-top: 48px;
  padding: 16px 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
  margin-bottom: 22px;
  padding: 18px 20px;
  background: rgba(255, 253, 250, 0.82);
  backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: var(--shadow);
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 14px;
}

.topbar h1 {
  margin: 0 0 4px;
  font-size: 1.6rem;
}

.topbar p {
  margin: 0;
  color: var(--muted);
}

.topbar-right {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chip {
  display: inline-flex;
  align-items: center;
  padding: 10px 14px;
  border-radius: 999px;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line);
}

.chip:hover {
  text-decoration: none;
  background: var(--accent-soft);
}

.menu-toggle {
  display: none;
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: 12px;
  width: 42px;
  height: 42px;
  font-size: 20px;
}

.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 22px;
  align-items: start;
}

.content {
  min-width: 0;
}

.prose {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 34px;
  box-shadow: var(--shadow);
  line-height: 1.72;
}

.prose h1,
.prose h2,
.prose h3 {
  scroll-margin-top: 110px;
}

.prose hr {
  display: none;
}

.prose h1 {
  font-size: 2rem;
  margin-top: 0;
}

.prose h2 {
  font-size: 1.35rem;
  margin-top: 3rem;
  padding-top: 0;
}

.prose h3 {
  font-size: 1.08rem;
  margin-top: 2rem;
}

.prose p,
.prose li {
  color: var(--text);
}

.prose ul,
.prose ol {
  padding-left: 1.2rem;
}

.prose blockquote {
  margin: 1.2rem 0;
  padding: 0.9rem 1rem;
  border-left: 4px solid var(--accent);
  background: var(--panel-2);
  border-radius: 10px;
}

.prose code {
  background: var(--panel-2);
  padding: 0.12rem 0.35rem;
  border-radius: 6px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.prose pre {
  position: relative;
  white-space: pre-wrap;
  word-break: break-word;
  padding: 1rem;
  padding-top: 2.6rem;
  border-radius: 14px;
  background: #222;
  color: #f7f7f7;
}

.prose pre code {
  background: none;
  padding: 0;
  border-radius: 0;
  color: inherit;
}

.copy-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  padding: 4px 10px;
  font-size: 0.78rem;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 8px;
  background: rgba(255,255,255,0.1);
  color: #ccc;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.copy-btn:hover {
  background: rgba(255,255,255,0.2);
  color: #fff;
}

.copy-btn.copied {
  color: #7dcea0;
  border-color: #7dcea0;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
}

.prose th,
.prose td {
  border: 1px solid var(--line);
  padding: 0.7rem;
  text-align: left;
}

.toc-panel {
  position: sticky;
  top: 108px;
}

.toc {
  display: grid;
  gap: 8px;
}

.toc-link {
  display: block;
  color: var(--muted);
  padding: 6px 0;
  font-size: 0.95rem;
  text-decoration: none;
}

.toc-link:hover {
  color: var(--text);
  text-decoration: none;
}

.toc-link.active {
  color: var(--text);
  font-weight: 600;
}

.empty-toc {
  color: var(--muted);
  font-size: 0.95rem;
}

@media (max-width: 1080px) {
  .content-grid {
    grid-template-columns: 1fr;
  }

  .toc-panel {
    position: static;
  }
}

@media (max-width: 880px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: min(86vw, 320px);
    transform: translateX(-102%);
    transition: transform 0.25s ease;
    z-index: 40;
    background: rgba(255, 253, 250, 0.98);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .menu-toggle {
    display: inline-grid;
    place-items: center;
  }

  .topbar {
    padding: 16px;
  }

  .topbar-right {
    display: none;
  }

  .main-shell {
    padding: 14px;
  }

  .prose {
    padding: 22px 18px;
  }
}