:root {
  --sidebar-w: 252px;
  --bg:          #ffffff;
  --sidebar-bg:  #f8fafc;
  --border:      #e2e8f0;
  --text:        #1e293b;
  --muted:       #64748b;
  --accent:      #4f46e5;
  --accent-lite: #eef2ff;
  --type-c:      #7c3aed;
  --req-c:       #ef4444;
  --ok-c:        #16a34a;
  --code-bg:     #0f172a;
  --tok-text:    #cbd5e1;
  --tok-str:     #86efac;
  --tok-num:     #fb923c;
  --tok-key:     #93c5fd;
  --tok-bool:    #f472b6;
  --tok-cm:      #475569;
  --tok-kw:      #c084fc;
  --tok-fn:      #67e8f9;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  font-size: 15px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}

/* ── Layout ── */
.layout { display: flex; min-height: 100vh; }

/* ── Sidebar ── */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 28px 0 40px;
}
.sb-logo {
  padding: 0 22px 22px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 20px;
}
.sb-logo-name {
  font-size: 18px;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -.3px;
}
.sb-logo-sub { font-size: 12px; color: var(--muted); margin-top: 3px; }

.sb-group { margin-bottom: 4px; }
.sb-group-title {
  padding: 5px 22px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
}
.sb-link {
  display: block;
  padding: 6px 22px;
  font-size: 14px;
  color: var(--text);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: all .12s;
}
.sb-link:hover { color: var(--accent); background: var(--accent-lite); }
.sb-link.is-sub { padding-left: 36px; font-size: 13px; color: var(--muted); }
.sb-link.is-sub:hover { color: var(--accent); }

/* ── Content ── */
.content {
  flex: 1;
  min-width: 0;
  padding: 56px 72px 80px;
  max-width: 980px;
}

section { margin-bottom: 80px; }

h2 {
  font-size: 30px;
  font-weight: 800;
  letter-spacing: -.5px;
  margin-bottom: 8px;
  scroll-margin-top: 24px;
}
h3 {
  font-size: 19px;
  font-weight: 700;
  margin: 36px 0 10px;
  scroll-margin-top: 24px;
  padding-top: 8px;
}
h3 + p { margin-top: 0; }

p { margin-bottom: 14px; color: var(--text); }

.lead {
  font-size: 17px;
  color: var(--muted);
  margin-bottom: 28px;
  line-height: 1.55;
}

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

/* ── Code ── */
pre {
  background: var(--code-bg);
  border-radius: 10px;
  padding: 22px 24px;
  overflow-x: auto;
  margin: 16px 0;
  font-size: 13.5px;
  line-height: 1.7;
  position: relative;
}
code {
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Courier New', monospace;
}
pre code { color: var(--tok-text); }

:not(pre) > code {
  background: #f1f5f9;
  color: #334155;
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 13px;
  border: 1px solid var(--border);
}

/* syntax tokens */
.t-kw   { color: var(--tok-kw); }
.t-fn   { color: var(--tok-fn); }
.t-key  { color: var(--tok-key); }
.t-str  { color: var(--tok-str); }
.t-num  { color: var(--tok-num); }
.t-bool { color: var(--tok-bool); }
.t-cm   { color: var(--tok-cm); font-style: italic; }

/* ── Tables ── */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  margin: 14px 0 28px;
}
th {
  text-align: left;
  padding: 8px 14px;
  border: 1px solid var(--border);
  background: #f8fafc;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--muted);
}
td {
  padding: 10px 14px;
  border: 1px solid var(--border);
  vertical-align: top;
  line-height: 1.5;
}
tr:hover td { background: #fafbfd; }

.t-name { font-family: monospace; font-weight: 700; font-size: 14px; }
.t-type { color: var(--type-c); font-family: monospace; font-size: 13px; }
.t-req  { color: var(--req-c); font-size: 11px; font-weight: 700; }
.t-opt  { color: var(--muted); font-size: 11px; }

/* return table header in green */
.ret-table th {
  background: #f0fdf4;
  border-color: #bbf7d0;
  color: #166534;
}

/* ── Method signature box ── */
.sig {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 20px;
  font-family: monospace;
  font-size: 15px;
  margin-bottom: 16px;
}

/* ── Callouts ── */
.callout {
  display: flex;
  gap: 12px;
  padding: 14px 18px;
  border-radius: 8px;
  margin: 16px 0;
  font-size: 14px;
  line-height: 1.55;
}
.callout-note { background: #eff6ff; border-left: 3px solid #3b82f6; }
.callout-warn { background: #fffbeb; border-left: 3px solid #f59e0b; }
.callout-icon { font-size: 16px; flex-shrink: 0; padding-top: 1px; }

/* ── Feature list ── */
.features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 24px;
  margin: 18px 0 28px;
}
.feat {
  display: flex;
  gap: 8px;
  font-size: 14px;
  align-items: flex-start;
}
.feat-ok { color: var(--ok-c); font-weight: 700; flex-shrink: 0; }

hr { border: none; border-top: 1px solid var(--border); margin: 44px 0; }

/* ── Demo layout ── */
.demo-wrap {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 24px;
  align-items: start;
}

.demo-panel {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
}
.demo-panel-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--muted);
  margin-bottom: 18px;
}

.df { margin-bottom: 16px; }
.df > label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}
.df input[type="number"],
.df select {
  width: 100%;
  padding: 7px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: #fff;
  font-size: 14px;
  color: var(--text);
  outline: none;
  appearance: none;
}
.df input[type="number"]:focus,
.df select:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-lite); }

.df-price { display: grid; grid-template-columns: 1fr 76px; gap: 8px; }

.radios { display: flex; flex-wrap: wrap; gap: 6px; }
.rb {
  cursor: pointer;
  padding: 5px 13px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
  background: #fff;
  color: var(--muted);
  transition: all .12s;
  user-select: none;
  display: flex;
  align-items: center;
}
.rb input { display: none; }
.rb.on { background: var(--accent); color: #fff; border-color: var(--accent); font-weight: 600; }

.chk-row {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-size: 13px;
}
.chk-row input { width: 15px; height: 15px; cursor: pointer; accent-color: var(--accent); }

.df-rates { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }

/* Result panel */
.result-panel {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  margin-bottom: 16px;
}
.result-panel-hdr {
  padding: 11px 18px;
  background: #f8fafc;
  border-bottom: 1px solid var(--border);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--muted);
}
.result-rows { padding: 14px 18px; display: grid; gap: 9px; }
.rrow {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 8px;
  align-items: baseline;
  font-size: 14px;
}
.rrow .rl { color: var(--muted); white-space: nowrap; }
.rrow .rd { border-bottom: 1px dashed #e2e8f0; }
.rrow .rv { font-weight: 700; font-family: monospace; font-size: 14px; white-space: nowrap; }

.total-box {
  margin: 0 18px 18px;
  background: var(--accent-lite);
  border-radius: 8px;
  padding: 14px 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.total-box .tb-label { font-weight: 700; color: var(--accent); }
.total-box .tb-val { font-size: 22px; font-weight: 800; color: var(--accent); font-family: monospace; }
.total-box .tb-alt { font-size: 13px; color: var(--muted); margin-top: 2px; }

/* Code snippet */
.snippet-wrap { position: relative; }
.snippet-wrap pre { margin: 0; border-radius: 10px; font-size: 12.5px; padding: 18px 20px; }
.copy-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  padding: 4px 10px;
  background: #1e293b;
  border: 1px solid #334155;
  color: #94a3b8;
  border-radius: 5px;
  font-size: 11px;
  cursor: pointer;
  font-family: monospace;
  transition: all .12s;
}
.copy-btn:hover { background: #334155; color: #e2e8f0; }
.copy-btn.done { color: var(--tok-str); border-color: var(--tok-str); }

@media (max-width: 900px) {
  .sidebar { display: none; }
  .content { padding: 32px 20px 60px; }
  .demo-wrap { grid-template-columns: 1fr; }
  .features { grid-template-columns: 1fr; }
}