/* =========================================================
   Build With Grok — multi-page design system (showcase v3)
   ========================================================= */

:root {
  --bg: #06080f;
  --bg-elevated: #0c121c;
  --bg-card: rgba(16, 24, 40, 0.82);
  --bg-glass: rgba(12, 18, 32, 0.55);
  --bg-sidebar: rgba(6, 10, 18, 0.97);
  --border: rgba(160, 176, 200, 0.14);
  --border-strong: rgba(125, 211, 252, 0.42);
  --text: #f5f8fd;
  --text-muted: #c5d0e0;
  --text-dim: #96a8bf;
  --cyan: #3ce4f7;
  --cyan-soft: rgba(60, 228, 247, 0.14);
  --violet: #b8a0ff;
  --violet-soft: rgba(184, 160, 255, 0.14);
  --amber: #ffd666;
  --amber-soft: rgba(255, 214, 102, 0.12);
  --rose: #ff7a90;
  --green: #52e892;
  --green-soft: rgba(82, 232, 146, 0.12);
  --glow-cyan: 0 0 48px rgba(60, 228, 247, 0.22);
  --glow-violet: 0 0 48px rgba(184, 160, 255, 0.18);
  --surface-glass: blur(18px) saturate(1.35);
  --font-sans: "DM Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --font-display: "Syne", "DM Sans", system-ui, sans-serif;
  --radius: 16px;
  --radius-sm: 12px;
  --radius-lg: 22px;
  --shadow: 0 24px 64px rgba(0, 0, 0, 0.45);
  --shadow-soft: 0 8px 32px rgba(0, 0, 0, 0.28);
  --nav-h: 60px;
  --side-w: 280px;
  --max: 700px;
  --max-wide: 1120px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --prose-lh: 1.8;
  --prose-size: 1.0625rem;
  --space-section: clamp(3.25rem, 5.5vw, 5rem);
  --code-bg: #080e18;
  --code-fg: #e6eef8;
  --ring: 0 0 0 1px rgba(60, 228, 247, 0.22), 0 0 0 4px rgba(60, 228, 247, 0.08);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 20px);
  background: var(--bg);
  color-scheme: dark;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--prose-size);
  line-height: var(--prose-lh);
  color: var(--text);
  background: var(--bg);
  background-color: #070a12;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  min-height: 100%;
  /* Always readable without JS — no opacity:0 entrance */
  opacity: 1;
}

img { max-width: 100%; height: auto; display: block; }

a {
  color: var(--cyan);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}
a:hover { color: #67e8f9; }

/* Progress */
#scroll-progress {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  z-index: 1000;
  background: linear-gradient(90deg, var(--cyan), var(--violet), var(--amber));
  box-shadow: 0 0 16px rgba(34, 211, 238, 0.55);
  transition: width 0.08s linear;
}

/* Topnav */
.site-nav, [data-topnav] {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 900;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0 1.1rem;
  background: rgba(7, 9, 15, 0.82);
  backdrop-filter: blur(16px) saturate(1.2);
  border-bottom: 1px solid var(--border);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--text);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.98rem;
  letter-spacing: -0.02em;
}
.nav-brand:hover { color: var(--text); }

.brand-mark {
  width: 26px; height: 26px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--cyan), var(--violet));
  box-shadow: 0 0 18px rgba(34, 211, 238, 0.35);
  position: relative;
  flex-shrink: 0;
}
.brand-mark::after {
  content: "";
  position: absolute;
  inset: 6px;
  border-radius: 3px;
  border: 2px solid rgba(7, 9, 15, 0.55);
}

.top-meta {
  display: none;
  align-items: center;
  gap: 0.75rem;
  margin-left: auto;
  margin-right: 0.5rem;
}
@media (min-width: 720px) {
  .top-meta { display: flex; }
}

.top-track, .lesson-track {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
  border: 1px solid var(--border);
}
.top-track.cyan, .lesson-track.cyan { color: var(--cyan); background: var(--cyan-soft); border-color: rgba(34,211,238,0.25); }
.top-track.violet, .lesson-track.violet { color: var(--violet); background: var(--violet-soft); border-color: rgba(167,139,250,0.25); }
.top-track.amber, .lesson-track.amber { color: var(--amber); background: var(--amber-soft); border-color: rgba(251,191,36,0.25); }
.top-track.green, .lesson-track.green { color: var(--green); background: var(--green-soft); border-color: rgba(52,211,153,0.25); }

.top-progress, .lesson-time, .lesson-pos {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-dim);
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.5rem 0.6rem;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 18px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s var(--ease), opacity 0.2s;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (min-width: 1080px) {
  body.has-sidebar .nav-toggle { display: none; }
}

/* Drawer */
.nav-drawer {
  position: fixed;
  top: var(--nav-h);
  right: 0; bottom: 0;
  width: min(320px, 90vw);
  background: var(--bg-sidebar);
  border-left: 1px solid var(--border);
  padding: 1rem 0.85rem 2rem;
  transform: translateX(100%);
  transition: transform 0.35s var(--ease);
  z-index: 850;
  overflow-y: auto;
}
.nav-drawer.open { transform: translateX(0); }
.nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
  z-index: 800;
}
.nav-overlay.open { opacity: 1; pointer-events: auto; }

/* Layout with sidebar */
.layout {
  display: grid;
  grid-template-columns: 1fr;
  min-height: 100vh;
  padding-top: var(--nav-h);
}

.sidebar {
  display: none;
  position: sticky;
  top: var(--nav-h);
  height: calc(100vh - var(--nav-h));
  overflow-y: auto;
  padding: 1.15rem 0.75rem 2.5rem;
  border-right: 1px solid var(--border);
  background: var(--bg-sidebar);
  scrollbar-width: thin;
  scrollbar-color: rgba(148,163,184,0.25) transparent;
}

@media (min-width: 1080px) {
  body.has-sidebar .layout {
    grid-template-columns: var(--side-w) 1fr;
  }
  body.has-sidebar .sidebar { display: block; }
}

.side-head { margin-bottom: 1.25rem; padding: 0 0.4rem; }
.side-home {
  display: inline-block;
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
}
.side-home:hover { color: var(--cyan); }
.side-label {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin: 0;
}

.side-track { margin-bottom: 1.15rem; }
.side-track-name {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.35rem 0.5rem;
  margin-bottom: 0.25rem;
}
.side-track-name.cyan { color: var(--cyan); }
.side-track-name.violet { color: var(--violet); }
.side-track-name.amber { color: var(--amber); }
.side-track-name.green { color: var(--green); }

.side-list { list-style: none; margin: 0; padding: 0; }
.side-link {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.5rem 0.6rem;
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.4;
  border: 1px solid transparent;
}
.side-link:hover { color: var(--text); background: rgba(255,255,255,0.04); }
.side-link.active {
  color: var(--cyan);
  background: var(--cyan-soft);
  border-color: rgba(45, 212, 239, 0.18);
  font-weight: 600;
}
.side-time {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-dim);
  flex-shrink: 0;
}

.main-col {
  min-width: 0;
  width: 100%;
}

/* Content shells */
.wrap {
  width: min(var(--max-wide), calc(100% - 2.25rem));
  margin-inline: auto;
}
.wrap.narrow {
  width: min(var(--max), calc(100% - 2.25rem));
}

.section {
  padding: var(--space-section) 0;
  position: relative;
}
.section.tight { padding: calc(var(--space-section) * 0.7) 0; }

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 0.75rem;
}
.section-label::before {
  content: "";
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 12px var(--cyan);
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  letter-spacing: -0.03em;
  color: var(--text);
  line-height: 1.15;
}

.lesson-header {
  padding: 2.25rem 0 1.4rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.75rem;
}
.lesson-header h1 {
  font-size: clamp(1.85rem, 3.8vw, 2.55rem);
  margin: 0.7rem 0 0.75rem;
  letter-spacing: -0.035em;
  line-height: 1.08;
}
.lesson-header .lead {
  font-size: 1.14rem;
  color: var(--text-muted);
  max-width: 54ch;
  margin: 0;
  line-height: 1.72;
}
.lesson-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  align-items: center;
}

.prose h2 {
  font-size: clamp(1.4rem, 2.4vw, 1.75rem);
  margin: 2.5rem 0 0.8rem;
  letter-spacing: -0.03em;
  line-height: 1.2;
}
.prose h3 {
  font-size: 1.12rem;
  margin: 1.85rem 0 0.55rem;
  letter-spacing: -0.02em;
}
.prose h4 {
  font-size: 1rem;
  margin: 1.4rem 0 0.45rem;
  font-family: var(--font-sans);
  letter-spacing: -0.01em;
}
.prose p {
  color: var(--text-muted);
  margin: 0 0 1.2rem;
  max-width: 65ch;
  font-size: 1.05em;
  line-height: var(--prose-lh);
}
.prose p strong, .prose li strong {
  color: var(--text);
  font-weight: 600;
}
.prose ul, .prose ol {
  color: var(--text-muted);
  margin: 0 0 1.35rem;
  padding-left: 1.35rem;
  max-width: 65ch;
}
.prose li {
  margin-bottom: 0.55rem;
  line-height: 1.7;
  padding-left: 0.15rem;
}
.prose li::marker { color: var(--cyan); }

/* Hub hero */
.hub-hero {
  position: relative;
  min-height: min(88vh, 820px);
  display: flex;
  align-items: flex-end;
  padding: 2rem 0 3.5rem;
  overflow: hidden;
}
.hub-hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hub-hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  opacity: 0.5;
}
.hub-hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(7,9,15,0.3) 0%, rgba(7,9,15,0.55) 45%, rgba(7,9,15,0.97) 90%, var(--bg) 100%),
    radial-gradient(ellipse 70% 45% at 50% 15%, rgba(34,211,238,0.12), transparent 60%);
}
.hub-hero .wrap { position: relative; z-index: 1; }
.hub-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: rgba(7,9,15,0.55);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 0.84rem;
  letter-spacing: 0.06em;
  margin-bottom: 1.1rem;
}
.hub-hero h1 {
  font-size: clamp(2.35rem, 6vw, 3.85rem);
  line-height: 1.02;
  margin: 0 0 1rem;
  max-width: 15ch;
  background: linear-gradient(135deg, #fff 0%, #c8d6f0 42%, #67e8f9 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hub-sub {
  font-size: clamp(1.08rem, 2vw, 1.22rem);
  color: var(--text-muted);
  max-width: 46ch;
  margin: 0 0 1.65rem;
  line-height: 1.7;
}
.hub-heading {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 2.8vw, 2rem);
  margin: 0 0 0.85rem;
  letter-spacing: -0.03em;
  line-height: 1.15;
}
.hub-lead {
  color: var(--text-muted);
  max-width: 56ch;
  margin: 0 0 1.5rem;
  line-height: 1.72;
  font-size: 1.05rem;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.75rem;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  color: var(--text-dim);
  font-size: 0.88rem;
}
.hero-meta strong { color: var(--text-muted); font-weight: 600; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.78rem 1.2rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.94rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s var(--ease), box-shadow 0.2s, background 0.2s, border-color 0.2s;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(135deg, #22d3ee, #818cf8);
  color: #041018;
  box-shadow: 0 10px 30px rgba(34,211,238,0.25);
}
.btn-primary:hover { color: #041018; box-shadow: 0 14px 40px rgba(34,211,238,0.35); }
.btn-ghost {
  background: rgba(255,255,255,0.04);
  border-color: var(--border);
  color: var(--text);
}
.btn-ghost:hover {
  border-color: var(--border-strong);
  color: var(--text);
  background: rgba(255,255,255,0.07);
}

/* Cards & grids */
.card-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}
@media (min-width: 700px) {
  .card-grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
  .card-grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
}
@media (min-width: 960px) {
  .card-grid.cols-4 { grid-template-columns: repeat(4, 1fr); }
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.3rem;
  backdrop-filter: blur(10px);
  transition: border-color 0.25s, transform 0.25s var(--ease), box-shadow 0.25s;
}
.card:hover {
  border-color: var(--border-strong);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.card h3, .card h4 {
  margin-top: 0;
  margin-bottom: 0.4rem;
  font-size: 1.05rem;
}
.card p { margin: 0; color: var(--text-muted); font-size: 1rem; line-height: 1.65; }
.card p + p { margin-top: 0.65rem; }
.card .icon {
  width: 40px; height: 40px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  margin-bottom: 0.85rem;
  font-size: 1.1rem;
  background: var(--cyan-soft);
  color: var(--cyan);
}
.card .icon.violet { background: var(--violet-soft); color: var(--violet); }
.card .icon.amber { background: var(--amber-soft); color: var(--amber); }
.card .icon.green { background: var(--green-soft); color: var(--green); }

.track-card {
  display: block;
  padding: 1.4rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: inherit;
  transition: border-color 0.25s, transform 0.25s var(--ease);
}
.track-card:hover {
  border-color: var(--border-strong);
  transform: translateY(-2px);
  color: inherit;
}
.track-card .track-name {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}
.track-card.cyan .track-name { color: var(--cyan); }
.track-card.violet .track-name { color: var(--violet); }
.track-card.amber .track-name { color: var(--amber); }
.track-card.green .track-name { color: var(--green); }
.track-card h3 {
  margin: 0 0 0.4rem;
  font-size: 1.25rem;
}
.track-card p {
  margin: 0 0 1rem;
  color: var(--text-muted);
  font-size: 0.94rem;
}
.track-card .lessons {
  list-style: none;
  margin: 0;
  padding: 0;
}
.track-card .lessons li {
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.4rem 0;
  border-top: 1px solid rgba(148,163,184,0.08);
  font-size: 0.88rem;
  color: var(--text-muted);
}
.track-card .lessons a {
  color: var(--text);
  font-weight: 500;
}
.track-card .lessons a:hover { color: var(--cyan); }

/* Split media */
.split {
  display: grid;
  gap: 2rem;
  align-items: center;
}
@media (min-width: 860px) {
  .split { grid-template-columns: 1.05fr 0.95fr; gap: 2.5rem; }
  .split.reverse { grid-template-columns: 0.95fr 1.05fr; }
  .split.reverse .split-media { order: -1; }
}
.split-media {
  position: relative;
  border-radius: calc(var(--radius) + 4px);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  background: var(--bg-elevated);
}
.split-media img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}
.split-media.square img { aspect-ratio: 1; }
.media-caption {
  position: absolute;
  left: 0.85rem;
  bottom: 0.85rem;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  background: rgba(7,10,18,0.88);
  border: 1px solid rgba(160,176,200,0.22);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  backdrop-filter: blur(8px);
}

.figure {
  margin: 1.5rem 0 1.75rem;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
.figure img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}
.figure.square img { aspect-ratio: 1; max-height: 420px; object-fit: cover; margin-inline: auto; }
.figure figcaption {
  padding: 0.8rem 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--text-muted);
  background: rgba(255,255,255,0.03);
  border-top: 1px solid var(--border);
}

/* Code */
.pre-wrap { position: relative; margin: 1.15rem 0 1.4rem; }
pre {
  margin: 0;
  padding: 1.15rem 1.25rem;
  background: var(--code-bg);
  border: 1px solid rgba(160, 176, 200, 0.2);
  border-radius: var(--radius-sm);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--code-fg);
  tab-size: 2;
}
pre .comment { color: #8b9cb3; }
pre .cmd { color: var(--cyan); }
pre .flag { color: var(--violet); }
pre .str { color: #86efac; }
pre .prompt { color: var(--amber); }

.copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  padding: 0.28rem 0.55rem;
  font-size: 0.85rem;
  font-family: var(--font-mono);
  color: var(--text-dim);
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
}
.copy-btn:hover { color: var(--text); border-color: var(--border-strong); }
.copy-btn.copied { color: var(--green); border-color: rgba(52,211,153,0.4); }

code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  color: #b8f6ff;
  background: rgba(56, 223, 245, 0.14);
  padding: 0.16em 0.45em;
  border-radius: 6px;
  border: 1px solid rgba(56, 223, 245, 0.15);
}
pre code { background: none; padding: 0; color: inherit; font-size: inherit; border: none; }

/* Tables */
.table-wrap {
  overflow-x: auto;
  margin: 1.15rem 0 1.6rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
}
table { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
th, td {
  text-align: left;
  padding: 0.9rem 1.05rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
  line-height: 1.55;
}
th {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-dim);
  background: rgba(255,255,255,0.02);
  white-space: nowrap;
}
td { color: var(--text-muted); }
tr:last-child td { border-bottom: none; }
td:first-child, th:first-child { color: var(--text); }
td code { white-space: nowrap; }

/* Callouts */
.callout {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.85rem;
  padding: 1.05rem 1.15rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
  margin: 1.4rem 0;
}
.callout.tip { border-color: rgba(34,211,238,0.25); background: var(--cyan-soft); }
.callout.warn { border-color: rgba(251,191,36,0.28); background: var(--amber-soft); }
.callout.pro { border-color: rgba(167,139,250,0.28); background: var(--violet-soft); }
.callout.lab { border-color: rgba(52,211,153,0.28); background: var(--green-soft); }
.callout .mark {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--cyan);
  padding-top: 0.15rem;
}
.callout.warn .mark { color: var(--amber); }
.callout.pro .mark { color: var(--violet); }
.callout.lab .mark { color: var(--green); }
.callout p { margin: 0; color: var(--text-muted); font-size: 1.02em; line-height: 1.65; }
.callout p + p { margin-top: 0.5rem; }

/* Lists */
.clean-list { list-style: none; padding: 0; margin: 0 0 1.2rem; }
.clean-list li {
  position: relative;
  padding: 0.65rem 0 0.65rem 1.5rem;
  color: var(--text-muted);
  border-bottom: 1px solid rgba(148,163,184,0.1);
  line-height: 1.65;
  font-size: 1.02em;
}
.clean-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 0.95rem;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--cyan), var(--violet));
}
.clean-list li:last-child { border-bottom: none; }

.steps { counter-reset: step; list-style: none; padding: 0; margin: 1.4rem 0; }
.steps li {
  counter-increment: step;
  position: relative;
  padding: 0 0 1.75rem 3.25rem;
  color: var(--text-muted);
  line-height: 1.7;
  font-size: 1.02em;
}
.steps li:last-child { padding-bottom: 0; }
.steps li::before {
  content: counter(step);
  position: absolute;
  left: 0; top: 0;
  width: 2.1rem; height: 2.1rem;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--cyan);
  background: var(--cyan-soft);
  border: 1px solid rgba(34,211,238,0.3);
}
.steps li::after {
  content: "";
  position: absolute;
  left: 1rem;
  top: 2.25rem;
  bottom: 0.1rem;
  width: 2px;
  background: linear-gradient(180deg, rgba(34,211,238,0.35), transparent);
}
.steps li:last-child::after { display: none; }
.steps strong { display: block; color: var(--text); margin-bottom: 0.15rem; }

/* Prompt pairs */
.prompt-pair {
  display: grid;
  gap: 0.75rem;
  margin: 1.15rem 0 1.5rem;
}
@media (min-width: 760px) {
  .prompt-pair { grid-template-columns: 1fr 1fr; }
}
.prompt-box {
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  padding: 1rem 1.05rem;
  background: var(--bg-card);
}
.prompt-box.bad { border-color: rgba(251,113,133,0.25); background: rgba(251,113,133,0.06); }
.prompt-box.good { border-color: rgba(52,211,153,0.28); background: var(--green-soft); }
.prompt-box .label {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}
.prompt-box.bad .label { color: var(--rose); }
.prompt-box.good .label { color: var(--green); }
.prompt-box p { margin: 0; font-size: 1rem; line-height: 1.65; color: var(--text-muted); }

/* Kbd */
.kbd-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 0.7rem 0 1.15rem;
  align-items: center;
}
kbd, .kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.7em;
  padding: 0.18em 0.5em;
  border-radius: 7px;
  border: 1px solid rgba(148,163,184,0.25);
  background: linear-gradient(180deg, #1a2234, #111827);
  box-shadow: 0 2px 0 rgba(0,0,0,0.35), inset 0 1px 0 rgba(255,255,255,0.05);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text);
  white-space: nowrap;
}
.pill {
  display: inline-flex;
  align-items: center;
  padding: 0.28rem 0.6rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* TOC on hub */
.path-list { display: grid; gap: 0.55rem; }
.path-list a {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.85rem;
  align-items: center;
  padding: 0.9rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-muted);
  transition: border-color 0.2s, transform 0.2s var(--ease);
}
.path-list a:hover {
  border-color: var(--border-strong);
  transform: translateX(3px);
  color: var(--text);
}
.path-list .num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--cyan);
}
.path-list .title { color: var(--text); font-weight: 600; font-size: 0.95rem; }
.path-list .path-blurb {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.45;
}
.path-list .meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* Pager */
.pager {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 0.75rem;
  align-items: stretch;
  margin: 3rem 0 1rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}
.pager-link {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  padding: 1rem 1.1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text);
  min-height: 72px;
  justify-content: center;
}
.pager-link:hover {
  border-color: var(--border-strong);
  color: var(--text);
}
.pager-link.prev { align-items: flex-start; }
.pager-link.next { align-items: flex-end; text-align: right; }
.pager-link.disabled {
  opacity: 0;
  pointer-events: none;
  border: none;
  background: transparent;
}
.pager-dir {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-dim);
}
.pager-title { font-weight: 600; font-size: 0.95rem; }
.pager-home {
  align-self: center;
  font-size: 0.85rem;
  color: var(--text-dim);
  padding: 0.5rem;
}
.pager-home:hover { color: var(--cyan); }

/* Mastery levels */
.mastery-track {
  display: grid;
  gap: 1rem;
}
@media (min-width: 800px) {
  .mastery-track { grid-template-columns: repeat(3, 1fr); }
}
.level {
  position: relative;
  padding: 1.3rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  overflow: hidden;
}
.level::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
}
.level.l1::before { background: linear-gradient(90deg, var(--cyan), transparent); }
.level.l2::before { background: linear-gradient(90deg, var(--violet), transparent); }
.level.l3::before { background: linear-gradient(90deg, var(--amber), transparent); }
.level .badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
  color: var(--cyan);
}
.level.l2 .badge { color: var(--violet); }
.level.l3 .badge { color: var(--amber); }
.level h3 { margin: 0 0 0.45rem; font-size: 1.12rem; }
.level p { margin: 0; color: var(--text-muted); font-size: 0.92rem; }

/* Stats */
.stat-strip {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.7rem;
  margin: 1.5rem 0;
}
@media (min-width: 700px) {
  .stat-strip { grid-template-columns: repeat(4, 1fr); }
}
.stat {
  padding: 0.95rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
}
.stat .n {
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: var(--text);
  letter-spacing: -0.02em;
}
.stat .l {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 0.15rem;
}

/* TOC anchor list in lesson */
.on-this-page {
  margin: 1.25rem 0 2rem;
  padding: 1rem 1.1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
}
.on-this-page strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 0.55rem;
}
.on-this-page a {
  display: block;
  padding: 0.28rem 0;
  color: var(--text-muted);
  font-size: 0.92rem;
}
.on-this-page a:hover { color: var(--cyan); }

/* Command encyclopedia cards */
.cmd-group { margin: 2rem 0; }
.cmd-group > h3 {
  position: sticky;
  top: calc(var(--nav-h) + 8px);
  z-index: 5;
  background: linear-gradient(180deg, var(--bg) 70%, transparent);
  padding: 0.5rem 0;
  margin: 0 0 0.75rem;
}
.cmd-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1rem 1.1rem;
  margin-bottom: 0.65rem;
  background: var(--bg-card);
}
.cmd-item h4 {
  margin: 0 0 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  letter-spacing: 0;
  color: var(--cyan);
}
.cmd-item .aliases {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-bottom: 0.4rem;
}
.cmd-item p { margin: 0; font-size: 0.92rem; color: var(--text-muted); }

/* Reveal */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.65s var(--ease), transform 0.65s var(--ease);
}
.reveal.visible { opacity: 1; transform: none; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2.25rem 0 3rem;
  color: var(--text-dim);
  font-size: 0.9rem;
  margin-top: 1rem;
}
.site-footer .wrap {
  display: grid;
  gap: 1rem;
}
@media (min-width: 720px) {
  .site-footer .wrap {
    grid-template-columns: 1.4fr 1fr;
    align-items: end;
  }
}
.site-footer h3 {
  font-size: 1.1rem;
  margin: 0 0 0.4rem;
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem 1.1rem;
}
.footer-links a { color: var(--text-muted); }
.footer-links a:hover { color: var(--cyan); }

.back-top {
  position: fixed;
  right: 1.15rem;
  bottom: 1.15rem;
  width: 42px; height: 42px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: rgba(13,17,28,0.9);
  color: var(--text);
  cursor: pointer;
  display: grid;
  place-items: center;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.25s, transform 0.25s var(--ease);
  z-index: 700;
  backdrop-filter: blur(10px);
}
.back-top.show {
  opacity: 1;
  pointer-events: auto;
  transform: none;
}
.back-top:hover { border-color: var(--border-strong); color: var(--cyan); }

.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  border: none;
  margin: 0;
}

.two-col {
  display: grid;
  gap: 1.5rem;
}
@media (min-width: 800px) {
  .two-col { grid-template-columns: 1fr 1fr; gap: 2rem; }
}

::selection {
  background: rgba(34,211,238,0.28);
  color: #fff;
}

/* Search filter on cheatsheet */
.filter-box {
  width: 100%;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: #0a0e18;
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  margin: 0 0 1.25rem;
  outline: none;
}
.filter-box:focus { border-color: var(--border-strong); }
.filter-box::placeholder { color: var(--text-dim); }

.cmd-item.is-hidden { display: none; }

/* ---- Hand-holding pedagogy ---- */
.you-will-see {
  margin: 1.25rem 0 1.5rem;
  padding: 1.1rem 1.2rem;
  border-radius: var(--radius-sm);
  border: 1px dashed rgba(34, 211, 238, 0.35);
  background: rgba(34, 211, 238, 0.06);
}
.you-will-see > strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 0.55rem;
}
.you-will-see p { margin: 0 0 0.55rem; color: var(--text-muted); }
.you-will-see p:last-child { margin-bottom: 0; }
.you-will-see ul {
  margin: 0.35rem 0 0;
  padding-left: 1.15rem;
  color: var(--text-muted);
}

.term {
  border-bottom: 1px dotted rgba(167, 139, 250, 0.55);
  cursor: help;
  color: var(--text);
}

.def-list {
  margin: 1.25rem 0 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--bg-card);
}
.def-list dt {
  font-weight: 600;
  color: var(--text);
  padding: 0.85rem 1rem 0.15rem;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--cyan);
}
.def-list dd {
  margin: 0;
  padding: 0 1rem 0.9rem;
  color: var(--text-muted);
  border-bottom: 1px solid rgba(148, 163, 184, 0.08);
}
.def-list dd:last-of-type { border-bottom: none; }

.if-stuck {
  margin: 1.4rem 0;
  padding: 1.1rem 1.2rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(251, 113, 133, 0.28);
  background: rgba(251, 113, 133, 0.06);
}
.if-stuck > strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--rose);
  margin-bottom: 0.5rem;
}
.if-stuck p, .if-stuck li { color: var(--text-muted); }
.if-stuck p { margin: 0 0 0.5rem; }
.if-stuck ul { margin: 0; padding-left: 1.15rem; }

.plain-box {
  margin: 1.25rem 0;
  padding: 1.1rem 1.2rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
}
.plain-box > strong {
  display: block;
  color: var(--text);
  margin-bottom: 0.4rem;
}
.plain-box p { margin: 0; color: var(--text-muted); }

.lesson-prereq {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0 0 1.25rem;
}
.lesson-prereq span {
  font-size: 0.82rem;
  color: var(--text-dim);
  padding: 0.3rem 0.65rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
}
.lesson-prereq a { color: var(--cyan); }

.steps li p {
  margin: 0.35rem 0 0;
  color: var(--text-muted);
}

.why {
  font-size: 0.92rem;
  color: var(--text-dim);
  border-left: 3px solid rgba(167, 139, 250, 0.45);
  padding: 0.35rem 0 0.35rem 0.85rem;
  margin: 0.65rem 0 1rem;
}

/* ========== Visual polish layer (v2) ========== */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(45, 212, 239, 0.07), transparent 50%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(167, 139, 250, 0.06), transparent 45%),
    radial-gradient(ellipse 50% 30% at 50% 100%, rgba(52, 211, 153, 0.04), transparent 50%);
}
body > * { position: relative; z-index: 1; }

.hub-hero-bg img {
  transform: scale(1.02);
  filter: saturate(1.08) contrast(1.05);
}
.hub-hero-bg::after {
  background:
    linear-gradient(180deg, rgba(6,8,14,0.25) 0%, rgba(6,8,14,0.5) 40%, rgba(6,8,14,0.94) 88%, var(--bg) 100%),
    radial-gradient(ellipse 70% 50% at 70% 30%, rgba(45,212,239,0.14), transparent 55%);
}

.hub-kicker {
  backdrop-filter: blur(10px);
  box-shadow: 0 0 24px rgba(45, 212, 239, 0.08);
}

.btn {
  letter-spacing: -0.01em;
}
.btn-primary {
  background: linear-gradient(135deg, #22d3ee 0%, #818cf8 55%, #a78bfa 100%);
  box-shadow: 0 8px 28px rgba(45, 212, 239, 0.28), inset 0 1px 0 rgba(255,255,255,0.25);
}
.btn-primary:hover {
  box-shadow: 0 12px 36px rgba(45, 212, 239, 0.4), inset 0 1px 0 rgba(255,255,255,0.3);
}

.card {
  position: relative;
  overflow: hidden;
}
.card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(145deg, rgba(45,212,239,0.18), transparent 40%, rgba(167,139,250,0.12));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
  opacity: 0.6;
}
.card:hover::before { opacity: 1; }

.track-card {
  position: relative;
  overflow: hidden;
}
.track-card::after {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), transparent);
  opacity: 0.85;
}
.track-card.violet::after { background: linear-gradient(90deg, var(--violet), transparent); }
.track-card.amber::after { background: linear-gradient(90deg, var(--amber), transparent); }
.track-card.green::after { background: linear-gradient(90deg, var(--green), transparent); }

/* Path stepper (hub) */
.path-stepper {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.65rem;
  margin: 1.5rem 0 0.5rem;
  position: relative;
}
@media (max-width: 800px) {
  .path-stepper { grid-template-columns: 1fr 1fr; }
}
.path-step {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  padding: 1rem 0.9rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-muted);
  transition: border-color 0.25s, transform 0.25s var(--ease), box-shadow 0.25s;
  min-height: 118px;
}
.path-step:hover {
  border-color: var(--border-strong);
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  color: var(--text);
}
.path-step .step-num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--cyan);
}
.path-step.violet .step-num { color: var(--violet); }
.path-step.amber .step-num { color: var(--amber); }
.path-step.green .step-num { color: var(--green); }
.path-step strong {
  color: var(--text);
  font-size: 0.98rem;
  letter-spacing: -0.02em;
}
.path-step span.desc {
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--text-muted);
}

/* Ship feature cards with media */
.ship-card {
  display: flex;
  flex-direction: column;
  padding: 0;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: border-color 0.25s, transform 0.25s var(--ease), box-shadow 0.25s;
}
.ship-card:hover {
  border-color: var(--border-strong);
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}
.ship-card .ship-media {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
}
.ship-card .ship-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s var(--ease);
}
.ship-card:hover .ship-media img { transform: scale(1.04); }
.ship-card .ship-body {
  padding: 1.25rem 1.3rem 1.4rem;
}
.ship-card .ship-body h3 {
  margin: 0 0 0.45rem;
  font-size: 1.15rem;
}
.ship-card .ship-body p {
  margin: 0 0 1rem;
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.65;
}
.ship-card .btn { align-self: flex-start; }

/* Progress pill in nav */
.progress-pill {
  display: none;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-dim);
  padding: 0.3rem 0.65rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.03);
}
@media (min-width: 720px) {
  .progress-pill { display: inline-flex; }
}
.progress-pill strong { color: var(--cyan); font-weight: 600; }

/* Sidebar done check */
.side-link.done .side-title::before {
  content: "✓ ";
  color: var(--green);
  font-size: 0.88em;
}
.side-link.done { opacity: 1; }

/* Path list row done */
.path-list a.done .num {
  color: var(--green);
}
.path-list a.done .title {
  opacity: 1;
}
.path-list a.done .title::after {
  content: " · opened";
  font-weight: 400;
  font-size: 0.8em;
  color: var(--green);
}

/* Ambient section band */
.section-band {
  position: relative;
}
.section-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent, rgba(45,212,239,0.03), transparent);
  pointer-events: none;
}

/* Banner under hero */
.journey-banner {
  border-radius: calc(var(--radius) + 6px);
  overflow: hidden;
  border: 1px solid var(--border);
  margin: 0 0 1.5rem;
  box-shadow: var(--shadow);
}
.journey-banner img {
  width: 100%;
  aspect-ratio: 21 / 7;
  object-fit: cover;
  max-height: 220px;
}
.journey-banner figcaption {
  padding: 0.75rem 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.45;
  color: var(--text-muted);
  background: rgba(0,0,0,0.35);
  border-top: 1px solid var(--border);
}

/* Favicon-friendly brand pulse */
.brand-mark {
  animation: brand-pulse 4s ease-in-out infinite;
}
@keyframes brand-pulse {
  0%, 100% { box-shadow: 0 0 18px rgba(34, 211, 238, 0.35); }
  50% { box-shadow: 0 0 28px rgba(167, 139, 250, 0.45); }
}

/* Smooth reveal stagger helper */
.reveal.delay-1 { transition-delay: 0.08s; }
.reveal.delay-2 { transition-delay: 0.16s; }
.reveal.delay-3 { transition-delay: 0.24s; }

/* Pager glow */
.pager-link:hover {
  box-shadow: 0 0 0 1px rgba(45,212,239,0.2), var(--shadow);
}

/* Lesson header accent line */
.lesson-header {
  position: relative;
}
.lesson-header::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: min(120px, 30%);
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), transparent);
  border-radius: 2px;
}

/* Table polish */
.table-wrap {
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.03);
}
th {
  background: rgba(45, 212, 239, 0.04);
}

/* Callout icons via mark spacing */
.callout {
  backdrop-filter: blur(8px);
}

/* Mobile nav brand shrink */
@media (max-width: 480px) {
  .brand-text { font-size: 0.9rem; }
  .hero-actions .btn { width: 100%; justify-content: center; }
}

/* Focus visible for a11y */
a:focus-visible, button:focus-visible, .btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* Reduce motion */
@media (prefers-reduced-motion: reduce) {
  .brand-mark { animation: none; }
  .reveal { transition: none; opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
  body { opacity: 1 !important; }
}



/* ========== Phase 1: mastery progress ========== */
.lesson-complete-bar {
  margin: 2rem 0 1rem;
  padding: 1.15rem 1.25rem;
  border-radius: var(--radius);
  border: 1px solid var(--border-strong);
  background: var(--cyan-soft);
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  align-items: flex-start;
}
.complete-hint {
  margin: 0;
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.55;
  max-width: 60ch;
}
.complete-status {
  font-weight: 600;
  color: var(--text);
}
.complete-status.is-complete,
.complete-btn.is-complete {
  color: var(--green);
}
.phase-check {
  margin: 0.75rem 0 1.25rem;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(74, 222, 128, 0.08);
}
.phase-check label {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--text);
  font-weight: 500;
  cursor: pointer;
  font-size: 1rem;
}
.phase-check input {
  width: 1.15rem;
  height: 1.15rem;
  accent-color: var(--green);
}
.self-check {
  margin: 2.5rem 0 1.5rem;
  padding: 1.35rem 1.4rem;
  border-radius: var(--radius);
  border: 1px solid var(--border-strong);
  background: var(--bg-card);
}
.self-check h2 {
  margin-top: 0;
}
.self-check fieldset {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin: 0 0 1rem;
  padding: 0.85rem 1rem 1rem;
}
.self-check legend {
  color: var(--text);
  font-weight: 600;
  padding: 0 0.35rem;
}
.self-check label {
  display: flex;
  gap: 0.55rem;
  align-items: flex-start;
  margin: 0.45rem 0;
  color: var(--text-muted);
  cursor: pointer;
  line-height: 1.5;
}
.self-check-result {
  margin: 0.85rem 0 0;
  font-weight: 600;
}
.self-check-result.ok { color: var(--green); }
.self-check-result.bad { color: var(--amber); }
.continue-card {
  border-radius: calc(var(--radius) + 4px);
  border: 1px solid var(--border-strong);
  background: linear-gradient(145deg, rgba(56,223,245,0.1), rgba(167,139,250,0.08));
  padding: 1.5rem 1.6rem;
  box-shadow: var(--shadow);
}
.continue-card-body .hub-heading { margin-bottom: 0.5rem; }
.side-link.completed .side-title::before {
  content: "✓ ";
  color: var(--green);
}
.side-link.opened:not(.completed) .side-title::before {
  content: "· ";
  color: var(--text-dim);
}
.path-list a.completed .num { color: var(--green); }
.path-list a.opened:not(.completed) .num { color: var(--amber); }

/* ========== Phase 2: search / jump palette ========== */
.search-open-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin-left: 0.35rem;
  padding: 0.35rem 0.65rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(14, 20, 32, 0.9);
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  cursor: pointer;
  flex-shrink: 0;
  transition: border-color 0.15s var(--ease), color 0.15s var(--ease), background 0.15s var(--ease);
}
.search-open-btn:hover,
.search-open-btn:focus-visible {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--cyan-soft);
  outline: none;
}
.search-open-label { display: none; }
@media (min-width: 900px) {
  .search-open-label { display: inline; }
}
.search-open-kbd {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.12rem 0.35rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: rgba(7, 10, 18, 0.85);
  color: var(--text-dim);
}

body.palette-open { overflow: hidden; }

.search-palette {
  position: fixed;
  inset: 0;
  z-index: 1200;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: min(12vh, 5rem) 1rem 2rem;
}
.search-palette[hidden] { display: none !important; }
.search-palette-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(4, 6, 12, 0.72);
  backdrop-filter: blur(6px);
}
.search-palette-panel {
  position: relative;
  z-index: 1;
  width: min(560px, 100%);
  max-height: min(70vh, 520px);
  display: flex;
  flex-direction: column;
  border-radius: calc(var(--radius) + 4px);
  border: 1px solid var(--border-strong);
  background: #0e1420;
  box-shadow: var(--shadow), 0 0 0 1px rgba(56, 223, 245, 0.08);
  overflow: hidden;
}
.search-palette-head {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border);
}
.search-palette-label {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.search-palette-input {
  flex: 1;
  min-width: 0;
  border: none;
  background: transparent;
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1.05rem;
  line-height: 1.4;
  outline: none;
  padding: 0.25rem 0;
}
.search-palette-input::placeholder { color: var(--text-dim); }
.search-palette-esc {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.15rem 0.4rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  color: var(--text-dim);
  flex-shrink: 0;
}
.search-palette-results {
  list-style: none;
  margin: 0;
  padding: 0.4rem;
  overflow-y: auto;
  flex: 1;
}
.search-result {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  padding: 0.65rem 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  border: 1px solid transparent;
}
.search-result:hover,
.search-result.is-active {
  background: var(--cyan-soft);
  border-color: rgba(56, 223, 245, 0.25);
}
.search-result-title {
  color: var(--text);
  font-weight: 600;
  font-size: 0.98rem;
}
.search-result-track {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--cyan);
}
.search-result-blurb {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.4;
}
.search-palette-empty {
  margin: 0;
  padding: 1.25rem 1rem;
  text-align: center;
  color: var(--text-dim);
}
.search-palette-hint {
  margin: 0;
  padding: 0.55rem 1rem 0.75rem;
  border-top: 1px solid var(--border);
  font-size: 0.78rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}


/* ========== Phase 3: last-verified version ribbon ========== */
.version-ribbon {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.4rem 0.75rem;
  margin: 0.85rem 0 1.25rem;
  padding: 0.7rem 0.95rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(252, 211, 77, 0.35);
  background: linear-gradient(135deg, rgba(252, 211, 77, 0.1), rgba(56, 223, 245, 0.06));
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.45;
}
.version-ribbon.is-stale {
  border-color: rgba(251, 113, 133, 0.45);
  background: linear-gradient(135deg, rgba(251, 113, 133, 0.12), rgba(252, 211, 77, 0.06));
}
.version-ribbon-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 600;
  color: var(--amber);
  padding: 0.12rem 0.4rem;
  border-radius: 6px;
  border: 1px solid rgba(252, 211, 77, 0.35);
  background: var(--amber-soft);
}
.version-ribbon.is-stale .version-ribbon-badge {
  color: var(--rose);
  border-color: rgba(251, 113, 133, 0.4);
  background: rgba(251, 113, 133, 0.12);
}
.version-ribbon-date {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text);
  font-size: 0.92rem;
}
.version-ribbon-cadence {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-dim);
}
.version-ribbon-note {
  flex: 1 1 100%;
  font-size: 0.86rem;
  color: var(--text-muted);
}
.version-ribbon-note code {
  font-size: 0.85em;
  padding: 0.05em 0.3em;
  border-radius: 4px;
  background: var(--code-bg);
  color: var(--code-fg);
}

/* ========== Walkthrough chrome: phase spy, badges, prompt bundles ========== */
.wt-sticky-spy {
  position: sticky;
  top: var(--nav-h);
  z-index: 80;
  margin: 0 0 0.75rem;
  padding: 0.55rem 0.85rem;
  background: rgba(8, 12, 20, 0.94);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-strong);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}
.wt-phase-spy {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.wt-spy-host .wt-phase-spy {
  margin-bottom: 0.65rem;
  padding-bottom: 0.65rem;
  border-bottom: 1px solid var(--border);
}
.wt-phase-spy-main {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.wt-phase-spy-label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  letter-spacing: -0.02em;
}
.wt-phase-spy-count {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--cyan);
  font-weight: 600;
}
.wt-phase-spy-next {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-muted);
}
.wt-phase-spy.is-complete .wt-phase-spy-label { color: var(--green); }
.wt-phase-spy-dots {
  list-style: none;
  margin: 0.25rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.wt-spy-dot {
  width: 1.65rem;
  height: 1.65rem;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  border: 1px solid var(--border);
  color: var(--text-dim);
  background: rgba(14, 20, 32, 0.9);
}
.wt-spy-dot.is-done {
  color: #04120a;
  background: var(--green);
  border-color: rgba(74, 222, 128, 0.5);
}
.wt-spy-dot.is-current {
  color: #041016;
  background: var(--cyan);
  border-color: rgba(56, 223, 245, 0.55);
  box-shadow: 0 0 0 2px rgba(56, 223, 245, 0.25);
}
.wt-spy-dot.is-todo {
  opacity: 0.85;
}

.phase-check {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem 1rem;
  margin: 0.5rem 0 1rem;
}
.wt-phase-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-weight: 600;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--text-dim);
  background: rgba(14, 20, 32, 0.85);
  white-space: nowrap;
}
.wt-phase-badge.is-done {
  color: var(--green);
  border-color: rgba(74, 222, 128, 0.4);
  background: var(--green-soft);
}
.wt-phase-badge.is-current {
  color: var(--cyan);
  border-color: rgba(56, 223, 245, 0.45);
  background: var(--cyan-soft);
}
.wt-phase-badge.is-todo {
  color: var(--text-dim);
}
h2.wt-phase-current {
  scroll-margin-top: calc(var(--nav-h) + 4.5rem);
}
h2.wt-phase-done {
  opacity: 0.92;
}
h2.wt-phase-done::after {
  content: " ✓";
  color: var(--green);
  font-weight: 600;
}

.pre-wrap.has-prompt-bundle {
  position: relative;
  padding-top: 2.4rem;
}
.prompt-bundle-btn {
  position: absolute;
  top: 0.45rem;
  right: 0.45rem;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.65rem;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: rgba(12, 18, 30, 0.95);
  color: var(--cyan);
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s var(--ease), color 0.15s var(--ease), border-color 0.15s var(--ease);
}
.prompt-bundle-btn:hover,
.prompt-bundle-btn:focus-visible {
  background: var(--cyan-soft);
  color: var(--text);
  outline: none;
}
.prompt-bundle-btn.is-current-phase {
  border-color: rgba(56, 223, 245, 0.55);
  box-shadow: 0 0 0 1px rgba(56, 223, 245, 0.2);
}
.prompt-bundle-btn.is-copied {
  color: var(--green);
  border-color: rgba(74, 222, 128, 0.45);
}
/* Don't collide with generic copy-btn from main.js */
.pre-wrap.has-prompt-bundle .copy-btn {
  top: 0.45rem;
  right: auto;
  left: 0.45rem;
}
@media (max-width: 560px) {
  .prompt-bundle-btn {
    position: static;
    margin: 0 0 0.5rem;
    width: 100%;
    justify-content: center;
  }
  .pre-wrap.has-prompt-bundle { padding-top: 0.5rem; }
}

/* ========== A11y: skip link, focus, reduced motion ========== */
.skip-link {
  position: absolute;
  left: 0.75rem;
  top: 0.75rem;
  z-index: 2000;
  padding: 0.55rem 0.9rem;
  border-radius: var(--radius-sm);
  background: var(--cyan);
  color: #041016;
  font-weight: 700;
  font-size: 0.9rem;
  text-decoration: none;
  transform: translateY(-150%);
  transition: transform 0.15s var(--ease);
  box-shadow: var(--shadow);
}
.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline: 3px solid var(--amber);
  outline-offset: 2px;
  color: #041016;
}

:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}
button:focus-visible,
a:focus-visible,
input:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* Keyboard path: visible focus on interactive chrome */
.search-open-btn:focus-visible,
.nav-toggle:focus-visible,
.complete-btn:focus-visible,
.prompt-bundle-btn:focus-visible,
.copy-btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

#main-content:focus {
  outline: none;
}
#main-content:focus-visible {
  outline: 2px dashed rgba(56, 223, 245, 0.45);
  outline-offset: 4px;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
}

/* ========== Perf: stable image layout ========== */
img {
  max-width: 100%;
  height: auto;
}
.figure img,
.hub-hero-bg img {
  width: 100%;
  object-fit: cover;
}

/* ========== Print: cheatsheet + lessons + walkthrough prompts ========== */
@media print {
  :root {
    --bg: #fff;
    --text: #111;
    --text-muted: #333;
    --text-dim: #444;
    --border: #ccc;
    --code-bg: #f4f4f4;
    --code-fg: #111;
  }
  html, body {
    background: #fff !important;
    background-color: #fff !important;
    color: #111 !important;
    font-size: 11pt;
    line-height: 1.45;
  }
  body { opacity: 1 !important; }

  .no-print,
  .site-nav,
  [data-topnav],
  .sidebar,
  [data-sidebar],
  .nav-drawer,
  .nav-overlay,
  .nav-toggle,
  .back-top,
  #scroll-progress,
  .search-palette,
  .search-open-btn,
  .wt-sticky-spy,
  .skip-link,
  .copy-btn,
  .prompt-bundle-btn,
  .complete-btn,
  .lesson-complete-bar,
  .pager,
  .hero-actions .btn-ghost,
  #reset-progress-btn,
  .path-stepper,
  .site-footer .footer-links {
    display: none !important;
  }

  .layout {
    display: block !important;
  }
  .main-col, .wrap, .prose, article {
    max-width: none !important;
    width: 100% !important;
    margin: 0 !important;
    padding: 0 !important;
  }

  a { color: #000 !important; text-decoration: underline; }
  a[href^="http"]::after,
  a[href^="../"]::after,
  a[href^="pages/"]::after {
    content: " (" attr(href) ")";
    font-size: 0.85em;
    color: #444;
    word-break: break-all;
  }
  a[href^="#"]::after { content: none; }

  .pre-wrap, pre, code {
    background: #f4f4f4 !important;
    color: #111 !important;
    border: 1px solid #ccc;
    white-space: pre-wrap;
    break-inside: avoid;
    page-break-inside: avoid;
  }
  .callout, .card, .prompt-box, .on-this-page, .version-ribbon, .wt-phase-spy {
    break-inside: avoid;
    page-break-inside: avoid;
    border: 1px solid #bbb !important;
    background: #fff !important;
    color: #111 !important;
    box-shadow: none !important;
  }
  .hub-hero-bg, .figure img {
    max-height: 180px;
    object-fit: cover;
  }
  h1, h2, h3 {
    color: #000 !important;
    page-break-after: avoid;
  }
  .print-only { display: block !important; }
}

.print-only { display: none; }

/* ========== Build With Grok: legal disclaimer + journey polish ========== */
.site-disclaimer,
[data-legal-disclaimer] {
  margin: 1rem 0 0;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(8, 12, 20, 0.85);
  color: var(--text-dim);
  font-size: 0.82rem;
  line-height: 1.55;
  max-width: 70ch;
}
.site-disclaimer strong {
  color: var(--text-muted);
  font-weight: 600;
}
.footer-legal {
  margin-top: 0.75rem;
  padding-bottom: 1.25rem;
}
.site-footer .footer-legal {
  border-top: 1px solid var(--border);
  padding-top: 1rem;
}
.practice-due-cue {
  color: var(--amber);
  font-weight: 500;
}
.practice-due-cue a {
  font-weight: 600;
}
@media print {
  .site-disclaimer,
  [data-legal-disclaimer] {
    color: #333 !important;
    border-color: #ccc !important;
    background: #fff !important;
  }
}

/* ========== Showcase beautify layer (v3 masterpiece) ========== */
html {
  background:
    radial-gradient(1200px 600px at 12% -8%, rgba(60, 228, 247, 0.09), transparent 55%),
    radial-gradient(900px 500px at 92% 0%, rgba(184, 160, 255, 0.08), transparent 50%),
    var(--bg);
}

body {
  background-color: #06080f;
  background-image:
    radial-gradient(ellipse 90% 55% at 50% -20%, rgba(60, 228, 247, 0.06), transparent 55%);
}

/* Fine grain (no image asset) */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9998;
  opacity: 0.035;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.site-nav, [data-topnav] {
  background: rgba(6, 9, 16, 0.72);
  backdrop-filter: var(--surface-glass);
  -webkit-backdrop-filter: var(--surface-glass);
  border-bottom: 1px solid rgba(160, 176, 200, 0.12);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.25);
  height: var(--nav-h);
}

.nav-brand {
  font-size: 1.02rem;
  letter-spacing: -0.03em;
  gap: 0.7rem;
}
.brand-mark {
  width: 28px;
  height: 28px;
  border-radius: 9px;
  background: linear-gradient(135deg, #3ce4f7 0%, #818cf8 48%, #c4b5fd 100%);
  box-shadow: var(--glow-cyan);
}
.brand-mark::after {
  inset: 7px;
  border-width: 2px;
  border-color: rgba(6, 9, 16, 0.55);
}

.progress-pill {
  border-radius: 999px;
  border: 1px solid rgba(60, 228, 247, 0.22);
  background: linear-gradient(135deg, rgba(60, 228, 247, 0.1), rgba(184, 160, 255, 0.08));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

/* Hub hero — cinematic */
.hub-hero {
  min-height: min(92vh, 900px);
  padding: calc(var(--nav-h) + 2.5rem) 0 4rem;
  isolation: isolate;
}
.hub-hero-bg img {
  opacity: 0.42;
  filter: saturate(1.15) contrast(1.08) brightness(0.92);
  transform: scale(1.04);
}
.hub-hero-bg::after {
  background:
    linear-gradient(105deg, rgba(6, 8, 15, 0.88) 0%, rgba(6, 8, 15, 0.45) 42%, rgba(6, 8, 15, 0.75) 100%),
    linear-gradient(180deg, rgba(6, 8, 15, 0.2) 0%, rgba(6, 8, 15, 0.55) 50%, rgba(6, 8, 15, 0.98) 92%, var(--bg) 100%),
    radial-gradient(ellipse 55% 45% at 75% 35%, rgba(60, 228, 247, 0.18), transparent 60%),
    radial-gradient(ellipse 40% 35% at 20% 70%, rgba(184, 160, 255, 0.12), transparent 55%);
}

/* Mesh orbs */
.hub-hero-orbs {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}
.hub-hero-orbs span {
  position: absolute;
  border-radius: 50%;
  filter: blur(40px);
  opacity: 0.55;
}
.hub-hero-orbs .orb-a {
  width: 280px; height: 280px;
  top: 12%; left: 8%;
  background: rgba(60, 228, 247, 0.22);
}
.hub-hero-orbs .orb-b {
  width: 320px; height: 320px;
  top: 25%; right: 5%;
  background: rgba(184, 160, 255, 0.18);
}
.hub-hero-orbs .orb-c {
  width: 200px; height: 200px;
  bottom: 18%; left: 40%;
  background: rgba(82, 232, 146, 0.1);
}

.hub-kicker {
  background: rgba(8, 14, 24, 0.65);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(60, 228, 247, 0.28);
  box-shadow: var(--glow-cyan), inset 0 1px 0 rgba(255, 255, 255, 0.08);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.78rem;
}

.hub-hero h1 {
  font-size: clamp(2.6rem, 7vw, 4.35rem);
  letter-spacing: -0.045em;
  max-width: 12ch;
  background: linear-gradient(125deg, #ffffff 0%, #e8eefc 28%, #7df0ff 58%, #c4b5fd 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 12px 40px rgba(60, 228, 247, 0.15));
  margin-bottom: 1.15rem;
}

.hub-sub {
  font-size: clamp(1.1rem, 2.1vw, 1.28rem);
  max-width: 48ch;
  color: var(--text-muted);
  line-height: 1.75;
}

.hero-actions { gap: 0.85rem; margin-bottom: 2rem; }

.hero-meta {
  gap: 0.65rem 1rem;
}
.hero-meta span {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(8, 12, 22, 0.55);
  backdrop-filter: blur(8px);
  font-size: 0.84rem;
}

/* Buttons — jewel quality */
.btn {
  padding: 0.85rem 1.35rem;
  border-radius: 999px;
  font-size: 0.95rem;
  letter-spacing: -0.015em;
  transition: transform 0.22s var(--ease), box-shadow 0.22s var(--ease), background 0.2s, border-color 0.2s, filter 0.2s;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }
.btn-primary {
  background: linear-gradient(135deg, #3ce4f7 0%, #6d8bff 45%, #b8a0ff 100%);
  color: #041018;
  border: 1px solid rgba(255, 255, 255, 0.18);
  box-shadow:
    0 12px 36px rgba(60, 228, 247, 0.32),
    inset 0 1px 0 rgba(255, 255, 255, 0.35);
}
.btn-primary:hover {
  color: #041018;
  filter: brightness(1.05);
  box-shadow:
    0 16px 48px rgba(60, 228, 247, 0.42),
    inset 0 1px 0 rgba(255, 255, 255, 0.4);
}
.btn-ghost {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(160, 176, 200, 0.22);
  backdrop-filter: blur(8px);
}
.btn-ghost:hover {
  background: rgba(60, 228, 247, 0.08);
  border-color: rgba(60, 228, 247, 0.35);
  box-shadow: var(--ring);
}

/* Glass cards */
.card, .track-card, .ship-card, .continue-card, .path-step {
  background: linear-gradient(160deg, rgba(22, 32, 52, 0.88), rgba(12, 18, 30, 0.78));
  border: 1px solid rgba(160, 176, 200, 0.14);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(12px);
}
.card {
  border-radius: var(--radius);
  padding: 1.4rem 1.45rem;
}
.card:hover {
  transform: translateY(-4px);
  border-color: rgba(60, 228, 247, 0.28);
  box-shadow: var(--shadow), var(--glow-cyan);
}
.card::before {
  opacity: 0.85;
  background: linear-gradient(145deg, rgba(60, 228, 247, 0.35), transparent 42%, rgba(184, 160, 255, 0.22));
}

.section-label {
  letter-spacing: 0.14em;
  font-size: 0.78rem;
  color: var(--cyan);
  opacity: 0.95;
}
.hub-heading {
  letter-spacing: -0.035em;
  background: linear-gradient(180deg, #fff 0%, #d5e0f2 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* Path stepper jewel */
.path-stepper {
  gap: 0.85rem;
  margin-top: 2rem;
}
.path-step {
  min-height: 132px;
  padding: 1.15rem 1rem;
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
}
.path-step::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(120% 80% at 0% 0%, rgba(60, 228, 247, 0.12), transparent 55%);
  pointer-events: none;
}
.path-step:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow), 0 0 0 1px rgba(60, 228, 247, 0.15);
}
.path-step .step-num {
  font-size: 0.78rem;
  letter-spacing: 0.12em;
}
.path-step strong {
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  color: var(--text);
}

/* Continue card */
.continue-card {
  border-radius: var(--radius-lg);
  border: 1px solid rgba(60, 228, 247, 0.28);
  background:
    radial-gradient(ellipse 80% 80% at 100% 0%, rgba(184, 160, 255, 0.12), transparent 50%),
    radial-gradient(ellipse 70% 70% at 0% 100%, rgba(60, 228, 247, 0.12), transparent 50%),
    linear-gradient(145deg, rgba(18, 28, 48, 0.95), rgba(10, 16, 28, 0.92));
  box-shadow: var(--shadow), var(--glow-cyan);
  padding: 1.75rem 1.85rem;
}

/* Ship cards */
.ship-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(160, 176, 200, 0.16);
  transition: transform 0.28s var(--ease), box-shadow 0.28s var(--ease), border-color 0.28s;
}
.ship-card:hover {
  transform: translateY(-6px);
  border-color: rgba(60, 228, 247, 0.3);
  box-shadow: var(--shadow), var(--glow-violet);
}
.ship-media img {
  transition: transform 0.5s var(--ease);
}
.ship-card:hover .ship-media img {
  transform: scale(1.04);
}

/* Showcase strip */
.hub-showcase {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(60, 228, 247, 0.22);
  background:
    linear-gradient(125deg, rgba(14, 22, 40, 0.95), rgba(18, 14, 36, 0.92));
  padding: clamp(1.5rem, 3vw, 2.25rem);
  box-shadow: var(--shadow-soft);
}
.hub-showcase::before {
  content: "";
  position: absolute;
  inset: -40% -20% auto auto;
  width: 55%;
  height: 120%;
  background: radial-gradient(circle, rgba(60, 228, 247, 0.16), transparent 65%);
  pointer-events: none;
}
.hub-showcase-grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 1.25rem;
  grid-template-columns: 1fr;
}
@media (min-width: 800px) {
  .hub-showcase-grid {
    grid-template-columns: 1.4fr 1fr;
    align-items: center;
  }
}
.hub-showcase .showcase-kicker {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--violet);
  margin-bottom: 0.65rem;
}
.hub-showcase h2 {
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2.6vw, 1.9rem);
  letter-spacing: -0.03em;
  margin: 0 0 0.75rem;
  color: var(--text);
}
.hub-showcase p {
  margin: 0;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 52ch;
}
.showcase-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.65rem;
}
.showcase-stat {
  padding: 0.9rem 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(160, 176, 200, 0.14);
  background: rgba(8, 12, 22, 0.55);
  text-align: center;
}
.showcase-stat strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: -0.03em;
  color: var(--cyan);
  margin-bottom: 0.2rem;
}
.showcase-stat span {
  font-size: 0.78rem;
  color: var(--text-dim);
  line-height: 1.35;
}

/* Lesson surfaces */
.lesson-header h1 {
  font-family: var(--font-display);
  letter-spacing: -0.035em;
  font-size: clamp(1.85rem, 3.5vw, 2.45rem);
  line-height: 1.12;
  background: linear-gradient(135deg, #fff 0%, #d0dbf0 70%, #9aeef8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.lesson-meta {
  gap: 0.5rem;
}
.on-this-page {
  border-radius: var(--radius);
  border: 1px solid rgba(160, 176, 200, 0.16);
  background: linear-gradient(160deg, rgba(16, 24, 40, 0.9), rgba(10, 14, 24, 0.85));
  box-shadow: var(--shadow-soft);
}
.callout {
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
}
.pre-wrap {
  border-radius: var(--radius-sm);
  border: 1px solid rgba(125, 211, 252, 0.12);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.03), var(--shadow-soft);
}
.prose h2 {
  letter-spacing: -0.03em;
  scroll-margin-top: calc(var(--nav-h) + 1.5rem);
}
.prose code {
  border-radius: 6px;
  border: 1px solid rgba(160, 176, 200, 0.12);
}

.site-footer {
  border-top: 1px solid rgba(160, 176, 200, 0.12);
  background:
    linear-gradient(180deg, transparent, rgba(8, 12, 22, 0.85)),
    var(--bg);
  padding: 2.5rem 0 1.5rem;
}
.site-footer h3 {
  font-family: var(--font-display);
  letter-spacing: -0.02em;
}

.sidebar {
  background: linear-gradient(180deg, rgba(8, 12, 20, 0.98), rgba(6, 10, 18, 0.99));
  border-right: 1px solid rgba(160, 176, 200, 0.1);
}
.side-link {
  border-radius: 10px;
  transition: background 0.15s, color 0.15s, box-shadow 0.15s;
}
.side-link.active {
  background: rgba(60, 228, 247, 0.1);
  box-shadow: inset 3px 0 0 var(--cyan);
}

/* Section band refinement */
.section-band {
  position: relative;
}
.section-band::before {
  opacity: 0.9;
  background:
    radial-gradient(ellipse 70% 80% at 50% 0%, rgba(60, 228, 247, 0.06), transparent 60%),
    linear-gradient(180deg, rgba(12, 18, 30, 0.4), transparent);
}

/* Search open btn glass */
.search-open-btn {
  backdrop-filter: blur(10px);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

/* Reduced motion keeps polish, not motion */
@media (prefers-reduced-motion: reduce) {
  .ship-card:hover .ship-media img,
  .card:hover,
  .path-step:hover,
  .btn:hover {
    transform: none;
  }
}

/* Design system markers for integrity (do not remove) */
.design-system-v3-showcase { --beautify-marker: 1; }