/* Python 101 — shared styles (hub + satellite pages) */
:root {
  --py-blue: #3776ab;
  --py-blue-d: #2d5f8a;
  --py-yellow: #ffd43b;
  --py-yellow-pale: #fff8e6;
  --bg: #f4f7fa;
  --surface: #ffffff;
  --surface2: #e8eef4;
  --ink: #1a2332;
  --ink2: #3d4a5c;
  --ink3: #6b7788;
  --border: #c5d0dc;
  --border2: #dce4ec;
  --code-bg: #1e293b;
  --code-text: #e2e8f0;
  --accent: var(--py-blue);
  --accent-pale: rgba(55, 118, 171, 0.1);
  --green: #2d7a3a;
  --green-pale: #e8f5eb;
  --amber: #b45309;
  --amber-pale: #fff7ed;
  --red: #b91c1c;
  --red-pale: #fef2f2;
}

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

body {
  background: var(--bg);
  color: var(--ink);
  font-family: "Source Sans 3", "Segoe UI", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

/* Sidebar */
#sidebar {
  position: fixed;
  left: 0; top: 0; bottom: 0;
  width: 268px;
  background: linear-gradient(180deg, #1e293b 0%, #0f172a 100%);
  overflow-y: auto;
  z-index: 100;
  padding-bottom: 2rem;
}

#sidebar::-webkit-scrollbar { width: 4px; }
#sidebar::-webkit-scrollbar-thumb { background: #334155; border-radius: 2px; }

.sb-logo {
  padding: 1.5rem 1.35rem 1.1rem;
  border-bottom: 1px solid #334155;
}

.sb-logo-mark {
  font-family: "JetBrains Mono", "IBM Plex Mono", monospace;
  font-weight: 700;
  font-size: 1.35rem;
  color: var(--py-yellow);
  letter-spacing: -0.02em;
}

.sb-logo-sub {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  color: #94a3b8;
  margin-top: 4px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.sb-search input {
  width: calc(100% - 2rem);
  margin: 0.75rem 1rem 0;
  background: #0f172a;
  border: 1px solid #334155;
  border-radius: 6px;
  padding: 8px 10px;
  color: #e2e8f0;
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
  outline: none;
}

.sb-search input:focus { border-color: var(--py-blue); }

.nav-group { padding: 0.85rem 0 0.35rem; }

.nav-group-label {
  font-family: "JetBrains Mono", monospace;
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #64748b;
  padding: 0 1.35rem;
  margin-bottom: 4px;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 1.35rem;
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
  color: #94a3b8;
  cursor: pointer;
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: all 0.15s;
}

.nav-link:hover { color: #e2e8f0; background: rgba(255, 255, 255, 0.04); }
.nav-link.active {
  color: var(--py-yellow);
  border-left-color: var(--py-yellow);
  background: rgba(255, 212, 59, 0.06);
}

.nav-dot {
  width: 5px; height: 5px;
  border-radius: 50%;
  background: #475569;
  flex-shrink: 0;
}

.nav-link.active .nav-dot { background: var(--py-yellow); }

#main { margin-left: 268px; min-height: 100vh; }

/* Hero */
.hero {
  background: linear-gradient(135deg, #1e3a5f 0%, #1e293b 45%, #0f172a 100%);
  padding: 3.5rem 3rem 3rem;
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: 1.25rem;
  right: 2rem;
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  color: #64748b;
  opacity: 0.6;
}

.hero-eyebrow {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  color: var(--py-yellow);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.hero h1 {
  font-family: "Source Sans 3", sans-serif;
  font-weight: 800;
  font-size: clamp(2rem, 4vw, 2.85rem);
  line-height: 1.1;
  color: #f8fafc;
  letter-spacing: -0.03em;
  max-width: 720px;
}

.hero h1 .py-word { color: var(--py-yellow); }

.hero-desc {
  margin-top: 1.1rem;
  font-size: 16px;
  color: #cbd5e1;
  max-width: 640px;
  line-height: 1.7;
}

.hero-chips {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.chip {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  padding: 4px 11px;
  border-radius: 20px;
  border: 1px solid;
}

.chip-gold { border-color: rgba(255, 212, 59, 0.45); color: var(--py-yellow); background: rgba(255, 212, 59, 0.08); }
.chip-muted { border-color: #334155; color: #94a3b8; }

.hero-stats {
  display: flex;
  gap: 2.5rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid #334155;
}

.stat-n { font-family: "JetBrains Mono", monospace; font-size: 1.75rem; font-weight: 700; color: var(--py-yellow); }
.stat-l { font-size: 10px; color: #64748b; text-transform: uppercase; letter-spacing: 0.06em; margin-top: 4px; }

.content { max-width: 860px; padding: 2.5rem 3rem 5rem; }

/* Hub cards (cross-page links) */
.hub-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 14px;
  margin: 1.5rem 0 2rem;
}

.hub-card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.35rem;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.hub-card:hover {
  border-color: var(--py-blue);
  box-shadow: 0 8px 24px rgba(55, 118, 171, 0.12);
}

.hub-card.current {
  border-color: var(--py-yellow);
  background: var(--py-yellow-pale);
}

.hub-card-icon {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.hub-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 6px;
}

.hub-card p {
  font-size: 13px;
  color: var(--ink3);
  line-height: 1.55;
}

.hub-card .hub-meta {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  color: var(--py-blue);
  margin-top: 10px;
}

/* Section headers */
.sec-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 1.5rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 2px solid var(--border);
}

.sec-header:first-child { border-top: none; margin-top: 0; padding-top: 0; }

.sec-num {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  font-weight: 600;
  color: var(--py-blue-d);
  background: var(--accent-pale);
  padding: 4px 10px;
  border-radius: 4px;
}

.sec-header h2 {
  font-weight: 800;
  font-size: 1.45rem;
  letter-spacing: -0.02em;
  color: var(--ink);
}

/* Topics */
.topic {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  margin-bottom: 16px;
  overflow: hidden;
}

.topic-header {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 1rem 1.25rem;
  cursor: pointer;
  user-select: none;
}

.topic-header:hover { background: #f8fafc; }

.topic-icon {
  width: 36px; height: 36px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  flex-shrink: 0;
}

.topic-title { flex: 1; }
.topic-title h3 { font-size: 1rem; font-weight: 700; color: var(--ink); margin-bottom: 2px; }
.topic-title p { font-size: 12px; color: var(--ink3); font-family: "JetBrains Mono", monospace; }

.topic-chev {
  color: var(--ink3);
  font-size: 11px;
  margin-top: 6px;
  transition: transform 0.2s;
}

.topic-chev.open { transform: rotate(180deg); }

.topic-body {
  display: none;
  border-top: 1px solid var(--border);
  padding: 1.25rem 1.35rem;
  background: #f8fafc;
}

.topic-body.open { display: block; }

.prose { color: var(--ink2); font-size: 14.5px; line-height: 1.75; margin-bottom: 12px; }
.prose code {
  font-family: "JetBrains Mono", monospace;
  font-size: 12.5px;
  background: var(--surface2);
  padding: 1px 6px;
  border-radius: 3px;
  color: var(--py-blue-d);
}

.code-wrap {
  background: var(--code-bg);
  border-radius: 8px;
  margin: 12px 0;
  overflow: hidden;
  border: 1px solid #334155;
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 14px;
  background: #0f172a;
  border-bottom: 1px solid #334155;
}

.code-lang {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--py-yellow);
  text-transform: uppercase;
}

.code-dots { display: flex; gap: 5px; }
.code-dot { width: 10px; height: 10px; border-radius: 50%; }
.dot-r { background: #ff5f57; }
.dot-y { background: #febc2e; }
.dot-g { background: #28c840; }

.copy-btn {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  color: #94a3b8;
  background: transparent;
  border: 1px solid #475569;
  border-radius: 3px;
  padding: 2px 8px;
  cursor: pointer;
}

.copy-btn:hover { color: #e2e8f0; }
.copy-btn.copied { color: var(--py-yellow); border-color: var(--py-yellow); }

pre {
  padding: 1rem 1.15rem;
  overflow-x: auto;
  font-family: "JetBrains Mono", monospace;
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--code-text);
}

.kw { color: #c792ea; }
.fn { color: #82aaff; }
.str { color: #c3e88d; }
.cm { color: #546e7a; font-style: italic; }
.num { color: #f78c6c; }
.dec { color: #ffcb6b; }

.alert {
  display: flex;
  gap: 12px;
  padding: 12px 14px;
  border-radius: 8px;
  margin: 12px 0;
  font-size: 13.5px;
}

.alert-icon { flex-shrink: 0; }
.alert-body { color: var(--ink2); line-height: 1.55; }

.alert-tip { background: var(--green-pale); border: 1px solid rgba(45, 122, 58, 0.25); }
.alert-warn { background: var(--amber-pale); border: 1px solid rgba(180, 83, 9, 0.25); }
.alert-info { background: #e0f2fe; border: 1px solid rgba(55, 118, 171, 0.25); }

.tag-row { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 10px; }
.tag {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  padding: 2px 8px;
  border-radius: 3px;
  border: 1px solid rgba(55, 118, 171, 0.35);
  background: var(--accent-pale);
  color: var(--py-blue-d);
}

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 12px 0;
}

.info-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  font-size: 13px;
  color: var(--ink2);
  line-height: 1.6;
}

.info-card-title {
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
  font-size: 13px;
}

.comp-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin: 10px 0;
}

.comp-table th {
  background: var(--ink);
  color: #e2e8f0;
  padding: 8px 12px;
  text-align: left;
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  font-weight: 600;
}

.comp-table td {
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
  font-size: 12.5px;
}

.comp-table tr:last-child td { border-bottom: none; }

.cross-ref {
  margin-top: 2.5rem;
  padding: 1.25rem 1.5rem;
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: 10px;
  font-size: 13px;
  color: var(--ink2);
}

.cross-ref strong { color: var(--ink); }

.cross-ref a {
  color: var(--py-blue-d);
  font-weight: 600;
}

.hidden { display: none !important; }

#menu-toggle {
  display: none;
  position: fixed;
  bottom: 1.25rem;
  right: 1.25rem;
  width: 48px;
  height: 48px;
  background: var(--py-blue);
  color: #fff;
  border: none;
  border-radius: 50%;
  font-size: 18px;
  cursor: pointer;
  z-index: 200;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

@media (max-width: 900px) {
  #sidebar { transform: translateX(-100%); transition: transform 0.3s; }
  #sidebar.open { transform: translateX(0); }
  #main { margin-left: 0; }
  .hero { padding: 2rem 1.25rem; }
  .content { padding: 1.5rem; }
  .two-col { grid-template-columns: 1fr; }
  #menu-toggle { display: flex; align-items: center; justify-content: center; }
}