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

:root {
  --bg:        #f6f8fa;
  --surface:   #ffffff;
  --surface2:  #f0f2f5;
  --border:    #d0d7de;
  --accent:    #7f52ff;
  --accent2:   #0969da;
  --accent3:   #9a6700;
  --accent4:   #cf222e;
  --text:      #1f2328;
  --muted:     #656d76;
  --tag-bg:    #ede7ff;
  --tag-text:  #5f3dcc;

  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  --font-sans: 'Inter', 'Segoe UI', system-ui, sans-serif;
  --radius: 12px;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.6;
  padding: 0 0 80px;
}

a { color: var(--accent2); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Hero ──────────────────────────────────────────────────── */
.hero {
  background: linear-gradient(135deg, #e3f7fb 0%, #eaf2ff 55%, #f3eefb 100%);
  border-bottom: 1px solid var(--border);
  padding: 40px 24px 34px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 40% at 30% 60%, rgba(127,82,255,.09) 0%, transparent 70%),
    radial-gradient(ellipse 50% 40% at 70% 40%, rgba(9,105,218,.05) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  background: var(--tag-bg);
  color: var(--tag-text);
  border: 1px solid #82cfaa;
  border-radius: 100px;
  padding: 4px 14px;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(1.7rem, 4vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1.1;
  margin-bottom: 10px;
}

.hero h1 span { color: var(--accent2); }

.hero p {
  font-size: 1rem;
  color: var(--muted);
  max-width: 520px;
  margin: 0 auto 20px;
}

.hero-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.hero-pills span {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-family: var(--font-mono);
  font-size: .78rem;
  padding: 5px 14px;
  color: var(--muted);
}

/* ── Layout ────────────────────────────────────────────────── */
.layout {
  display: grid;
  grid-template-columns: 200px 1fr;
  max-width: 1080px;
  margin: 0 auto;
}

.layout.has-toc {
  grid-template-columns: 200px 1fr 220px;
  max-width: 1300px;
  gap: 0;
}

/* ── Package Nav (left) ────────────────────────────────────── */
.pkg-nav {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 32px 0 32px 24px;
}

.home-link {
  display: block;
  font-weight: 700;
  font-size: .88rem;
  color: var(--text);
  padding: 4px 10px 18px;
  letter-spacing: -.01em;
  text-decoration: none;
}

.home-link:hover { color: var(--accent2); text-decoration: none; }
.home-link.active { color: var(--accent2); }

.nav-group {
  font-size: .62rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 4px 10px 6px;
  margin-top: 8px;
}

.pkg-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.pkg-list a {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: .86rem;
  font-family: var(--font-mono);
  color: var(--muted);
  padding: 7px 10px;
  border-radius: 7px;
  border: 1px solid transparent;
  transition: all .15s;
  text-decoration: none;
}

.pkg-list a:hover {
  color: var(--text);
  background: var(--surface);
  border-color: var(--border);
}

.pkg-list a.active {
  color: var(--accent2);
  background: rgba(9,105,218,.07);
  border-color: rgba(9,105,218,.2);
  font-weight: 600;
}

.pkg-list a .pkg-icon { font-size: .85rem; width: 18px; text-align: center; }

/* ── TOC (right) ───────────────────────────────────────────── */
.toc-nav {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 32px 24px 32px 0;
}

.toc-title {
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 12px;
  padding-left: 8px;
}

.toc {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.toc a {
  display: block;
  font-size: .8rem;
  color: var(--muted);
  padding: 5px 8px;
  border-radius: 6px;
  border-right: 2px solid transparent;
  transition: all .15s;
}

.toc a:hover {
  color: var(--text);
  background: var(--surface);
  border-right-color: var(--accent);
  text-decoration: none;
}

/* ── Main Content ──────────────────────────────────────────── */
.content {
  padding: 40px 40px 40px 32px;
  min-width: 0;
  border-left: 1px solid var(--border);
}

.layout.has-toc .content {
  padding: 40px 32px;
  border-right: 1px solid var(--border);
}

/* ── Home sections ─────────────────────────────────────────── */
.home-section { margin-bottom: 52px; }

.home-section-header {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.home-section-header h2 {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -.01em;
}

.home-section-header span {
  font-size: .78rem;
  color: var(--muted);
}

/* ── Topic cards (home) ───────────────────────────────────────── */
.card-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.topic-card {
  display: flex;
  gap: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  text-decoration: none;
  transition: border-color .15s, box-shadow .15s;
  position: relative;
}

.topic-card:hover {
  border-color: #adbac7;
  box-shadow: 0 2px 8px rgba(0,0,0,.06);
  text-decoration: none;
}

.topic-card.soon { opacity: .7; }
.topic-card.soon:hover { opacity: .85; }

.tc-icon {
  font-size: 1.4rem;
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  background: var(--surface2);
  border-radius: 8px;
  margin-top: 1px;
}

.tc-body { flex: 1; min-width: 0; }

.tc-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
}

.tc-title {
  font-size: .92rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -.01em;
}

.tc-desc {
  font-size: .8rem;
  color: var(--muted);
  line-height: 1.5;
  margin-bottom: 10px;
}

.tc-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.tc-tags span {
  font-family: var(--font-mono);
  font-size: .65rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 7px;
  color: var(--muted);
}

/* ── Section (content pages) ──────────────────────────────────── */
.section {
  margin-bottom: 60px;
  scroll-margin-top: 24px;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.section-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.icon-blue   { background: rgba(9,105,218,.1);   color: var(--accent2); }
.icon-green  { background: rgba(127,82,255,.1);   color: var(--accent);  }
.icon-gold   { background: rgba(154,103,0,.1);   color: var(--accent3); }
.icon-red    { background: rgba(207,34,46,.1);   color: var(--accent4); }
.icon-purple { background: rgba(130,80,223,.1);  color: #5a32a3;        }

.section-header h2 {
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -.02em;
}

.section-header .section-tag {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: .68rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 2px 10px;
  color: var(--muted);
}

/* ── Cards (content pages) ─────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 20px;
  transition: border-color .2s;
}

.card:hover { border-color: #adbac7; }

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px 12px;
  border-bottom: 1px solid var(--border);
  background: var(--surface2);
}

.card-title {
  font-size: .9rem;
  font-weight: 600;
  color: var(--text);
}

.card-badge {
  font-family: var(--font-mono);
  font-size: .65rem;
  border-radius: 6px;
  padding: 2px 8px;
  font-weight: 600;
}

.badge-blue   { background: rgba(9,105,218,.08);  color: var(--accent2); border: 1px solid rgba(9,105,218,.2);   }
.badge-green  { background: rgba(127,82,255,.08);  color: var(--accent);  border: 1px solid rgba(127,82,255,.2);   }
.badge-gold   { background: rgba(154,103,0,.08);  color: var(--accent3); border: 1px solid rgba(154,103,0,.2);   }
.badge-red    { background: rgba(207,34,46,.08);  color: var(--accent4); border: 1px solid rgba(207,34,46,.2);   }
.badge-purple { background: rgba(130,80,223,.08); color: #5a32a3;        border: 1px solid rgba(130,80,223,.2);  }

/* ── Code Block ────────────────────────────────────────────── */
.code-wrap {
  position: relative;
  padding: 20px 20px 18px;
}

pre {
  font-family: var(--font-mono);
  font-size: .82rem;
  line-height: 1.75;
  overflow-x: auto;
  tab-size: 4;
}

.kw  { color: #cf222e; }
.fn  { color: #8250df; }
.str { color: #0a3069; }
.cmt { color: #6e7781; font-style: italic; }
.num { color: #0550ae; }
.pkg { color: #0969da; }
.typ { color: #953800; }
.out { color: #1a7f37; }
.op  { color: #1f2328; }

/* ── Info callout ──────────────────────────────────────────── */
.callout {
  display: flex;
  gap: 12px;
  background: #ddf4ff;
  border: 1px solid #54aeff80;
  border-radius: 8px;
  padding: 14px 16px;
  margin-bottom: 20px;
  font-size: .86rem;
  color: #1f2328;
}

.callout.warn {
  background: #fff8c5;
  border-color: #d4a72c80;
}

.callout.tip {
  background: #dafbe1;
  border-color: #4ac26b80;
}

.callout-icon { flex-shrink: 0; font-size: 1rem; margin-top: 1px; }

/* ── Diagram ───────────────────────────────────────────────── */
.diagram {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 20px;
  overflow-x: auto;
}

.diagram pre {
  font-family: var(--font-mono);
  font-size: .8rem;
  line-height: 1.8;
  color: var(--text);
}

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* ── Reference table ───────────────────────────────────────── */
.ref-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .83rem;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}

.ref-table thead th {
  background: var(--surface2);
  padding: 10px 14px;
  text-align: left;
  font-weight: 600;
  font-size: .75rem;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
}

.ref-table tbody tr { border-bottom: 1px solid var(--border); }
.ref-table tbody tr:last-child { border-bottom: none; }
.ref-table tbody tr:hover { background: var(--surface2); }

.ref-table td { padding: 9px 14px; vertical-align: top; }

.ref-table td:first-child {
  font-family: var(--font-mono);
  font-size: .78rem;
  color: var(--accent3);
  white-space: nowrap;
}

.ref-table td:nth-child(2) {
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--accent2);
}

.ref-table td:last-child { color: var(--muted); }

/* ── Responsive ────────────────────────────────────────────── */
@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; }
  .pkg-nav, .toc-nav { display: none; }
  .content { padding: 24px 16px; border: none; }
  .card-grid { grid-template-columns: 1fr; }
  .two-col { grid-template-columns: 1fr; }
}