@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;700&family=Sora:wght@300;400;500;600;700&family=Space+Grotesk:wght@300;400;500;600&display=swap');

/* ── Dark mode (default) ── */
:root {
  --bg:             #0c0e14;
  --bg2:            #12151f;
  --bg3:            #181c28;
  --bg4:            #1e2333;
  --bg-code:        #0e1117;
  --border:         rgba(255, 255, 255, 0.07);
  --border2:        rgba(255, 255, 255, 0.14);
  --text:           #e8ecf5;
  --muted:          #8b95b0;
  --accent:         #fb923c;
  --accent2:        #fbbf24;
  --accent3:        #22d3ee;
  --accent4:        #34d399;
  --accent5:        #4f8ef7;
  --accent6:        #a78bfa;
  --accent7:        #f472b6;
  --accent-red:     #f87171;
  --mono:           'JetBrains Mono', 'Fira Code', monospace;
  --sans:           'Space Grotesk', system-ui, sans-serif;
  --sans-head:      'Sora', system-ui, sans-serif;
  --sidebar-w:      268px;
  --radius:         8px;
  --hl-keyword:     #a78bfa;
  --hl-string:      #34d399;
  --hl-number:      #fb923c;
  --hl-comment:     #4a5570;
  --hl-func:        #4f8ef7;
  --hl-class:       #22d3ee;
  --hl-attr:        #fbbf24;
  --hl-import:      #f472b6;
  --hl-op:          #8b95b0;
}

/* ── Light mode overrides ── */
:root[data-theme="light"] {
  --bg:             #f3f6fb;
  --bg2:            #ffffff;
  --bg3:            #e9eef6;
  --bg4:            #dae4f0;
  --bg-code:        #eef3f9;
  --border:         rgba(15, 23, 42, 0.1);
  --border2:        rgba(15, 23, 42, 0.18);
  --text:           #182135;
  --muted:          #5d6a82;
  --accent:         #e05c00;
  --accent2:        #b97b00;
  --accent3:        #0e7490;
  --accent4:        #0f7f5a;
  --accent5:        #2258c0;
  --accent6:        #6d34cc;
  --accent7:        #b03d82;
  --accent-red:     #c0392b;
  --hl-keyword:     #7f42d9;
  --hl-string:      #2f7a46;
  --hl-number:      #c96c2c;
  --hl-comment:     #7b8698;
  --hl-func:        #2268d2;
  --hl-class:       #0e7490;
  --hl-attr:        #b97b00;
  --hl-import:      #b03d82;
  --hl-op:          #6b7a96;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 14px;
  display: flex;
  min-height: 100vh;
}

/* ── Sidebar ── */
.sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  background: var(--bg2);
  border-right: 1px solid var(--border);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 24px 0 40px;
  flex-shrink: 0;
}

.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 2px; }

.logo {
  padding: 0 20px 20px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 16px;
}

.logo-title {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-title .logo-icon {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  background: linear-gradient(135deg, #e05c00 0%, #fb923c 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 800;
  color: #fff;
  flex-shrink: 0;
}

.logo-sub {
  font-size: 11px;
  color: var(--muted);
  margin-top: 3px;
  font-family: var(--sans);
  font-weight: 400;
}

.nav-section { margin-bottom: 4px; }

.nav-label {
  font-size: 10px;
  font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  padding: 10px 20px 4px;
  font-family: var(--mono);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 20px;
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  transition: color 0.15s, background 0.15s;
  border-left: 2px solid transparent;
  line-height: 1.3;
}

.nav-link .nav-icon { font-size: 13px; width: 16px; text-align: center; flex-shrink: 0; }
.nav-link:hover { color: var(--text); background: var(--bg3); }
.nav-link.active { color: var(--accent); border-left-color: var(--accent); background: rgba(251, 146, 60, 0.08); font-weight: 500; }

/* ── Main ── */
.main {
  flex: 1;
  max-width: 940px;
  padding: 40px 48px 80px;
  overflow-x: hidden;
}

/* ── Hero ── */
.hero {
  background: linear-gradient(135deg, rgba(251, 146, 60, 0.1) 0%, rgba(34, 211, 238, 0.05) 100%);
  border: 1px solid rgba(251, 146, 60, 0.22);
  border-radius: 12px;
  padding: 28px 32px;
  margin-bottom: 40px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -30px;
  right: -30px;
  width: 160px;
  height: 160px;
  background: radial-gradient(circle, rgba(251, 146, 60, 0.18), transparent 70%);
  pointer-events: none;
}

.hero-tag {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1.8px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
  opacity: 0.85;
}

.hero h1 {
  font-family: var(--sans-head);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.4px;
  color: var(--text);
  margin-bottom: 8px;
  line-height: 1.2;
}

.hero p {
  color: var(--muted);
  font-size: 14.5px;
  max-width: 580px;
  line-height: 1.65;
  margin-bottom: 0;
}

.hero-chips {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 18px;
}

.chip {
  font-family: var(--mono);
  font-size: 11.5px;
  padding: 4px 12px;
  border-radius: 6px;
  border: 1px solid;
  white-space: nowrap;
}

.chip-orange { color: var(--accent);  border-color: rgba(251, 146, 60, 0.35);  background: rgba(251, 146, 60, 0.08); }
.chip-blue   { color: var(--accent5); border-color: rgba(79, 142, 247, 0.35);  background: rgba(79, 142, 247, 0.08); }
.chip-green  { color: var(--accent4); border-color: rgba(52, 211, 153, 0.35);  background: rgba(52, 211, 153, 0.08); }
.chip-purple { color: var(--accent6); border-color: rgba(167, 139, 250, 0.35); background: rgba(167, 139, 250, 0.08); }
.chip-cyan   { color: var(--accent3); border-color: rgba(34, 211, 238, 0.35);  background: rgba(34, 211, 238, 0.08); }
.chip-pink   { color: var(--accent7); border-color: rgba(244, 114, 182, 0.35); background: rgba(244, 114, 182, 0.08); }

/* ── Sections ── */
section {
  margin-bottom: 60px;
  scroll-margin-top: 24px;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}

.section-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  flex-shrink: 0;
}

.icon-blue   { background: rgba(79, 142, 247, 0.15); }
.icon-cyan   { background: rgba(34, 211, 238, 0.15); }
.icon-green  { background: rgba(52, 211, 153, 0.15); }
.icon-orange { background: rgba(251, 146, 60, 0.15); }
.icon-purple { background: rgba(167, 139, 250, 0.15); }
.icon-pink   { background: rgba(244, 114, 182, 0.15); }
.icon-yellow { background: rgba(251, 191, 36, 0.15); }
.icon-red    { background: rgba(248, 113, 113, 0.15); }

.section-title-wrap h2 {
  font-family: var(--sans-head);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.3px;
  color: var(--text);
  margin: 0;
  padding: 0;
  border: none;
}

.section-title-wrap .section-sub {
  font-size: 12.5px;
  color: var(--muted);
  margin-top: 2px;
}

.section-divider {
  height: 1px;
  background: linear-gradient(to right, var(--border2), transparent);
  margin-bottom: 22px;
}

/* ── Typography ── */
h3 {
  font-family: var(--sans-head);
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin: 26px 0 10px;
}

h4 {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--muted);
  margin: 18px 0 8px;
}

p { color: var(--muted); margin-bottom: 10px; line-height: 1.7; font-size: 14px; }
p strong { color: var(--text); font-weight: 500; }
a { color: var(--accent5); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Inline code ── */
code {
  font-family: var(--mono);
  font-size: 12px;
  background: rgba(251, 146, 60, 0.09);
  color: var(--accent);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid rgba(251, 146, 60, 0.2);
}

:root[data-theme="light"] code {
  background: rgba(224, 92, 0, 0.08);
  border-color: rgba(224, 92, 0, 0.18);
}

/* ── Code blocks ── */
.code-wrap {
  background: var(--bg-code);
  border: 1px solid var(--border2);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 14px 0;
  font-family: var(--mono);
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 9px 16px;
  background: rgba(255, 255, 255, 0.03);
  border-bottom: 1px solid var(--border);
}

:root[data-theme="light"] .code-header {
  background: rgba(0, 0, 0, 0.03);
}

.code-lang {
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--muted);
}

.copy-btn {
  font-size: 11px;
  color: var(--muted);
  background: none;
  border: 1px solid var(--border2);
  border-radius: 4px;
  padding: 3px 9px;
  cursor: pointer;
  font-family: var(--mono);
  transition: color 0.2s, border-color 0.2s;
}

.copy-btn:hover { color: var(--accent); border-color: var(--accent); }

.code-block {
  padding: 16px 18px;
  overflow-x: auto;
  font-size: 12.5px;
  line-height: 1.7;
  white-space: pre;
  tab-size: 4;
}

/* ── Syntax highlighting ── */
.kw { color: var(--hl-keyword); }
.st { color: var(--hl-string); }
.nm { color: var(--hl-number); }
.cm { color: var(--hl-comment); font-style: italic; }
.fn { color: var(--hl-func); }
.cl { color: var(--hl-class); }
.im { color: var(--hl-import); }
.op { color: var(--hl-op); }
.at { color: var(--hl-attr); }

/* ── Cards ── */
.card {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 22px;
  margin-bottom: 14px;
}

:root[data-theme="light"] .card {
  background: var(--bg2);
  box-shadow: 0 2px 8px rgba(15, 23, 42, 0.05);
}

.card-title {
  font-family: var(--sans-head);
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.dot { width: 6px; height: 6px; border-radius: 50%; flex-shrink: 0; }
.dot-blue   { background: var(--accent5); }
.dot-green  { background: var(--accent4); }
.dot-orange { background: var(--accent); }
.dot-purple { background: var(--accent6); }
.dot-cyan   { background: var(--accent3); }
.dot-pink   { background: var(--accent7); }
.dot-yellow { background: var(--accent2); }
.dot-red    { background: var(--accent-red); }

.card p, .card li { color: var(--muted); font-size: 13.5px; }
.card ul { padding-left: 18px; }
.card ul li { margin-bottom: 4px; }

/* ── Info boxes ── */
.info-box {
  display: flex;
  gap: 12px;
  padding: 14px 18px;
  border-radius: var(--radius);
  margin: 14px 0;
  border-left: 4px solid;
}

.info-box.tip  { background: rgba(52, 211, 153, 0.07);  border-color: var(--accent4); }
.info-box.note { background: rgba(79, 142, 247, 0.07);  border-color: var(--accent5); }
.info-box.warn { background: rgba(251, 146, 60, 0.07);  border-color: var(--accent); }
.info-box.perf { background: rgba(167, 139, 250, 0.07); border-color: var(--accent6); }
.info-box.new  { background: rgba(34, 211, 238, 0.07);  border-color: var(--accent3); }

:root[data-theme="light"] .info-box.tip  { background: rgba(15, 127, 90, 0.06);  }
:root[data-theme="light"] .info-box.note { background: rgba(34, 88, 192, 0.06); }
:root[data-theme="light"] .info-box.warn { background: rgba(224, 92, 0, 0.06); }
:root[data-theme="light"] .info-box.perf { background: rgba(109, 52, 204, 0.06); }
:root[data-theme="light"] .info-box.new  { background: rgba(14, 116, 144, 0.06); }

.info-icon { font-size: 15px; flex-shrink: 0; margin-top: 1px; }
.info-content { font-size: 13px; color: var(--muted); line-height: 1.6; }
.info-content strong { color: var(--text); }

/* ── Grid ── */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }

/* ── Table ── */
.ref-table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 13px; }
.ref-table th {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 9px 14px;
  text-align: left;
  background: var(--bg3);
  border-bottom: 1px solid var(--border2);
}
.ref-table td {
  padding: 9px 14px;
  font-size: 13px;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.ref-table tr:last-child td { border-bottom: none; }
.ref-table tr:hover td { background: rgba(255, 255, 255, 0.02); }
:root[data-theme="light"] .ref-table tr:hover td { background: rgba(15, 23, 42, 0.02); }
.ref-table td code { font-size: 11px; }
.method-name { color: var(--accent); font-family: var(--mono); font-size: 12px; }

/* ── DataFrame visual ── */
.df-visual {
  background: var(--bg-code);
  border: 1px solid var(--border2);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 14px 0;
  font-family: var(--mono);
  font-size: 12px;
}
.df-visual table { width: 100%; border-collapse: collapse; }
.df-visual th {
  background: rgba(251, 146, 60, 0.1);
  color: var(--accent);
  padding: 8px 14px;
  text-align: left;
  font-weight: 600;
  font-size: 11.5px;
  border-bottom: 1px solid var(--border);
  text-transform: none;
  letter-spacing: normal;
}
:root[data-theme="light"] .df-visual th { background: rgba(224, 92, 0, 0.08); }
.df-visual th.idx { color: var(--muted); background: rgba(255, 255, 255, 0.03); }
:root[data-theme="light"] .df-visual th.idx { background: rgba(15, 23, 42, 0.03); }
.df-visual td { padding: 7px 14px; color: var(--muted); border-bottom: 1px solid var(--border); font-size: 11.5px; }
.df-visual td.idx { color: var(--muted); background: rgba(255, 255, 255, 0.02); font-weight: 500; }
:root[data-theme="light"] .df-visual td.idx { background: rgba(15, 23, 42, 0.02); }
.df-visual tr:last-child td { border-bottom: none; }
.df-visual tr:hover td { background: rgba(255, 255, 255, 0.02); }
:root[data-theme="light"] .df-visual tr:hover td { background: rgba(15, 23, 42, 0.02); }
.df-dtype { font-size: 10px; color: var(--muted); padding: 2px 14px 7px; }

/* ── Pipeline ── */
.pipeline {
  display: flex;
  align-items: center;
  gap: 0;
  flex-wrap: wrap;
  margin: 18px 0;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 22px;
}

.pipe-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  padding: 10px 14px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 12px;
  min-width: 84px;
}

:root[data-theme="light"] .pipe-step {
  background: rgba(0, 0, 0, 0.03);
}

.pipe-step .picon  { font-size: 20px; }
.pipe-step .plabel { font-family: var(--mono); font-size: 9.5px; color: var(--muted); letter-spacing: 0.8px; text-transform: uppercase; }
.pipe-step .pname  { font-size: 11.5px; color: var(--text); font-weight: 500; }
.pipe-arrow { color: var(--border2); font-size: 17px; margin: 0 5px; }

/* ── Scrollbars ── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 3px; }

/* ── Responsive ── */
@media (max-width: 900px) {
  .sidebar { display: none; }
  .main { padding: 28px 20px 60px; max-width: 100%; }
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .pipeline { flex-direction: column; align-items: flex-start; }
}