/* =========================================
   MathWiz.space — Design System
   Dark, mathematical, dashing.
   ========================================= */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,300..900&family=JetBrains+Mono:wght@400;500;700&family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
  /* Color tokens */
  --bg-0: #07070d;
  --bg-1: #0c0c18;
  --bg-2: #11112a;
  --surface: rgba(20, 20, 45, 0.55);
  --surface-2: rgba(30, 30, 65, 0.7);
  --border: rgba(140, 130, 255, 0.18);
  --border-strong: rgba(140, 130, 255, 0.4);

  --text-0: #f3f3ff;
  --text-1: #c8c8e6;
  --text-2: #8a8ab3;
  --text-3: #5a5a85;

  --accent-1: #7c5cff;       /* electric purple */
  --accent-2: #00e6ff;       /* cyan */
  --accent-3: #ff5cf2;       /* magenta */
  --accent-4: #ffd166;       /* gold (for highlights) */
  --success: #5cffa0;
  --danger: #ff5577;

  /* Typography */
  --font-display: 'Fraunces', 'Georgia', serif;
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Effects */
  --glow-purple: 0 0 30px rgba(124, 92, 255, 0.45);
  --glow-cyan: 0 0 30px rgba(0, 230, 255, 0.45);
  --glow-magenta: 0 0 30px rgba(255, 92, 242, 0.45);
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;

  --maxw: 1280px;
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-0);
  color: var(--text-0);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Animated mathematical background — graph paper + floating symbols */
.bg-stage {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(ellipse at 20% 10%, rgba(124, 92, 255, 0.18), transparent 50%),
    radial-gradient(ellipse at 80% 90%, rgba(0, 230, 255, 0.12), transparent 50%),
    radial-gradient(ellipse at 50% 50%, rgba(255, 92, 242, 0.05), transparent 60%),
    linear-gradient(180deg, var(--bg-0), var(--bg-1) 40%, var(--bg-0));
}

.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(140, 130, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(140, 130, 255, 0.05) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
  pointer-events: none;
}

.bg-symbols {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
}

.bg-symbols span {
  position: absolute;
  font-family: var(--font-display);
  font-size: clamp(1.2rem, 3vw, 2.4rem);
  color: rgba(124, 92, 255, 0.12);
  user-select: none;
  animation: floatUp linear infinite;
  white-space: nowrap;
}

@keyframes floatUp {
  from { transform: translateY(110vh) rotate(0deg); opacity: 0; }
  10% { opacity: 1; }
  90% { opacity: 1; }
  to { transform: translateY(-15vh) rotate(15deg); opacity: 0; }
}

/* ===== Top nav ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(18px) saturate(180%);
  -webkit-backdrop-filter: blur(18px) saturate(180%);
  background: rgba(7, 7, 13, 0.65);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 18px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-0);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.4rem;
  letter-spacing: -0.01em;
}
.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  display: grid;
  place-items: center;
  font-family: var(--font-display);
  font-weight: 800;
  color: var(--bg-0);
  font-size: 1.1rem;
  box-shadow: var(--glow-purple);
  position: relative;
}
.brand-mark::after {
  content: "";
  position: absolute;
  inset: -2px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
  z-index: -1;
  filter: blur(12px);
  opacity: 0.6;
}
.brand-text .accent { color: var(--accent-2); }
.brand-text small {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 400;
  color: var(--text-2);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-top: -2px;
}

.nav-links {
  display: flex;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  color: var(--text-1);
  text-decoration: none;
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 0.92rem;
  font-weight: 500;
  transition: all 0.2s ease;
}
.nav-links a:hover {
  color: var(--text-0);
  background: var(--surface);
}
.nav-cta {
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  color: var(--bg-0) !important;
  font-weight: 600 !important;
  box-shadow: 0 4px 18px rgba(124, 92, 255, 0.4);
}

/* ===== Hero ===== */
.hero {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 80px 28px 60px;
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 60px;
  align-items: center;
}
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; padding-top: 50px; gap: 40px; }
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent-2);
  margin-bottom: 24px;
  padding: 6px 14px;
  border: 1px solid rgba(0, 230, 255, 0.3);
  border-radius: 100px;
  background: rgba(0, 230, 255, 0.06);
}
.hero-eyebrow .dot {
  width: 8px;
  height: 8px;
  background: var(--accent-2);
  border-radius: 50%;
  box-shadow: 0 0 12px var(--accent-2);
  animation: pulse 1.6s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

h1.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 6vw, 4.5rem);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin: 0 0 24px;
  color: var(--text-0);
}
h1.hero-title .italic {
  font-style: italic;
  font-weight: 400;
  background: linear-gradient(135deg, var(--accent-2), var(--accent-1), var(--accent-3));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--text-1);
  max-width: 540px;
  margin: 0 0 36px;
}

.hero-cta {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 26px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.98rem;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  font-family: var(--font-sans);
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  color: var(--bg-0);
  box-shadow: 0 8px 30px rgba(124, 92, 255, 0.4);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 40px rgba(124, 92, 255, 0.6); }
.btn-ghost {
  background: var(--surface);
  color: var(--text-0);
  border-color: var(--border);
  backdrop-filter: blur(10px);
}
.btn-ghost:hover { border-color: var(--border-strong); background: var(--surface-2); }

.hero-stats {
  display: flex;
  gap: 36px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}
.hero-stat .num {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 600;
  background: linear-gradient(135deg, var(--accent-2), var(--accent-1));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-stat .label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-2);
  text-transform: uppercase;
  letter-spacing: 0.15em;
}

/* Hero visual: animated math hero canvas */
.hero-visual {
  position: relative;
  aspect-ratio: 1 / 1;
  max-width: 500px;
  margin: 0 auto;
}
.hv-canvas {
  width: 100%;
  height: 100%;
  display: block;
  border-radius: 24px;
  background: radial-gradient(circle at center, rgba(124, 92, 255, 0.08), transparent 70%);
}
.hv-badge {
  position: absolute;
  padding: 8px 14px;
  background: rgba(7, 7, 13, 0.85);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-1);
  display: flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 8px 20px rgba(0,0,0,0.4);
}
.hv-badge .dot { width: 6px; height: 6px; background: var(--accent-2); border-radius: 50%; }
.hv-1 { top: 8%; left: -8%; }
.hv-2 { bottom: 12%; right: -12%; }
.hv-3 { bottom: 40%; left: -14%; }

/* ===== Section header ===== */
.section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 80px 28px;
}
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 48px;
  gap: 24px;
  flex-wrap: wrap;
}
.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent-2);
  margin-bottom: 12px;
}
h2.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0;
  max-width: 720px;
}
.section-sub {
  color: var(--text-1);
  max-width: 480px;
  margin: 12px 0 0;
}

/* ===== Topic grid ===== */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 22px;
}

.topic-card {
  position: relative;
  display: block;
  padding: 30px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: var(--text-0);
  overflow: hidden;
  transition: all 0.3s ease;
  isolation: isolate;
}
.topic-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%), rgba(124, 92, 255, 0.18), transparent 50%);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: -1;
}
.topic-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4), var(--glow-purple);
}
.topic-card:hover::before { opacity: 1; }

.topic-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  margin-bottom: 22px;
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--bg-0);
  position: relative;
}
.topic-icon.purple { background: linear-gradient(135deg, var(--accent-1), #b794ff); }
.topic-icon.cyan { background: linear-gradient(135deg, var(--accent-2), #66f5ff); }
.topic-icon.magenta { background: linear-gradient(135deg, var(--accent-3), #ff9cf7); }
.topic-icon.gold { background: linear-gradient(135deg, var(--accent-4), #ffec99); }
.topic-icon.green { background: linear-gradient(135deg, var(--success), #b3ffce); }
.topic-icon.coral { background: linear-gradient(135deg, #ff8855, #ffc299); }

.topic-card h3 {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 600;
  margin: 0 0 10px;
  letter-spacing: -0.01em;
}
.topic-card .desc {
  font-size: 0.92rem;
  color: var(--text-2);
  margin: 0 0 22px;
  line-height: 1.55;
}
.topic-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-2);
}
.topic-meta .lessons { color: var(--accent-2); }
.topic-arrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--accent-2);
  font-weight: 600;
}
.topic-card:hover .topic-arrow { transform: translateX(4px); transition: transform 0.3s ease; }
.topic-arrow svg { transition: transform 0.3s ease; }
.topic-card:hover .topic-arrow svg { transform: translateX(4px); }

/* "Featured" badge */
.topic-card.featured {
  background: linear-gradient(135deg, rgba(124, 92, 255, 0.12), rgba(0, 230, 255, 0.08));
  border-color: rgba(124, 92, 255, 0.35);
}
.featured-tag {
  position: absolute;
  top: 18px;
  right: 18px;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  padding: 4px 10px;
  background: var(--accent-2);
  color: var(--bg-0);
  border-radius: 100px;
  font-weight: 700;
}

/* ===== Features row ===== */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}
.feature {
  padding: 26px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
}
.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(124, 92, 255, 0.15);
  color: var(--accent-2);
  display: grid;
  place-items: center;
  margin-bottom: 16px;
}
.feature h4 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  margin: 0 0 8px;
  font-weight: 600;
}
.feature p {
  margin: 0;
  color: var(--text-2);
  font-size: 0.92rem;
}

/* ===== Footer ===== */
.footer {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 60px 28px 40px;
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 40px;
}
@media (max-width: 720px) {
  .footer { grid-template-columns: 1fr 1fr; }
}
.footer-col h5 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--text-3);
  margin: 0 0 16px;
}
.footer-col ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.footer-col a { color: var(--text-1); text-decoration: none; font-size: 0.9rem; }
.footer-col a:hover { color: var(--accent-2); }
.footer-tagline { color: var(--text-2); font-size: 0.9rem; max-width: 320px; margin: 8px 0 0; }

.copyright {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 20px 28px 40px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-3);
  text-align: center;
  border-top: 1px solid var(--border);
}

/* =========================================
   TUTORIAL PAGE (matrix.html and others)
   ========================================= */

.tutorial-wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 40px 28px 80px;
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 48px;
  align-items: start;
}
@media (max-width: 980px) {
  .tutorial-wrap { grid-template-columns: 1fr; gap: 24px; }
}

.tut-sidebar {
  position: sticky;
  top: 90px;
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  max-height: calc(100vh - 110px);
  overflow-y: auto;
}
.tut-sidebar h6 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--text-3);
  margin: 0 0 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.tut-sidebar h6 .icon { color: var(--accent-2); }

.tut-progress {
  height: 4px;
  background: rgba(124, 92, 255, 0.15);
  border-radius: 100px;
  margin-bottom: 18px;
  overflow: hidden;
}
.tut-progress-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent-2), var(--accent-1));
  border-radius: 100px;
  transition: width 0.3s ease;
}

.tut-toc {
  list-style: none;
  padding: 0;
  margin: 0;
  counter-reset: toc;
}
.tut-toc li {
  counter-increment: toc;
  margin-bottom: 4px;
}
.tut-toc a {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 10px 12px;
  border-radius: 10px;
  color: var(--text-1);
  text-decoration: none;
  font-size: 0.9rem;
  transition: all 0.15s ease;
  border-left: 2px solid transparent;
}
.tut-toc a:hover { background: rgba(124, 92, 255, 0.08); color: var(--text-0); }
.tut-toc a.active {
  background: rgba(124, 92, 255, 0.12);
  color: var(--text-0);
  border-left-color: var(--accent-2);
}
.tut-toc a::before {
  content: counter(toc, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-3);
  flex-shrink: 0;
  padding-top: 2px;
}
.tut-toc a.active::before { color: var(--accent-2); }
.tut-toc a.done::before { content: "✓"; color: var(--success); }

.tut-main { min-width: 0; }

.tut-breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-2);
  margin-bottom: 14px;
}
.tut-breadcrumb a { color: var(--text-2); text-decoration: none; }
.tut-breadcrumb a:hover { color: var(--accent-2); }

.tut-hero {
  padding: 40px 0 36px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 36px;
}
.tut-hero .eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent-2);
  margin-bottom: 14px;
}
.tut-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 16px;
}
.tut-hero .lead {
  color: var(--text-1);
  font-size: 1.1rem;
  max-width: 680px;
}
.tut-hero-meta {
  display: flex;
  gap: 24px;
  margin-top: 22px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-2);
}
.tut-hero-meta span { display: inline-flex; align-items: center; gap: 6px; }
.tut-hero-meta strong { color: var(--accent-2); font-weight: 500; }

/* ===== Lesson blocks ===== */
.lesson {
  margin-bottom: 80px;
  scroll-margin-top: 90px;
}
.lesson-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 22px;
}
.lesson-num {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  color: var(--bg-0);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.9rem;
  flex-shrink: 0;
}
.lesson h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0;
}

.lesson-body p {
  color: var(--text-1);
  font-size: 1.02rem;
  margin: 0 0 18px;
}
.lesson-body strong { color: var(--text-0); font-weight: 600; }

.callout {
  padding: 18px 22px;
  border-radius: var(--radius);
  margin: 22px 0;
  display: flex;
  gap: 14px;
  align-items: flex-start;
}
.callout-icon {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
}
.callout-insight { background: rgba(124, 92, 255, 0.1); border: 1px solid rgba(124, 92, 255, 0.25); }
.callout-insight .callout-icon { background: var(--accent-1); color: var(--bg-0); }
.callout-tip { background: rgba(0, 230, 255, 0.08); border: 1px solid rgba(0, 230, 255, 0.25); }
.callout-tip .callout-icon { background: var(--accent-2); color: var(--bg-0); }
.callout-warn { background: rgba(255, 92, 242, 0.08); border: 1px solid rgba(255, 92, 242, 0.25); }
.callout-warn .callout-icon { background: var(--accent-3); color: var(--bg-0); }
.callout-body { color: var(--text-0); font-size: 0.96rem; }
.callout-body strong { color: var(--accent-2); font-weight: 600; }

/* Math display */
.math-block {
  margin: 24px 0;
  padding: 22px 24px;
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--text-0);
  text-align: center;
  overflow-x: auto;
  position: relative;
}
.math-block::before {
  content: "Math";
  position: absolute;
  top: 10px;
  left: 14px;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--text-3);
}
.math-inline {
  font-family: var(--font-display);
  font-style: italic;
  color: var(--accent-2);
  padding: 0 4px;
}

/* ===== Demo widget ===== */
.demo {
  margin: 32px 0;
  padding: 26px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  position: relative;
}
.demo-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
  gap: 12px;
  flex-wrap: wrap;
}
.demo-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--accent-2);
  background: rgba(0, 230, 255, 0.1);
  padding: 4px 10px;
  border-radius: 100px;
  border: 1px solid rgba(0, 230, 255, 0.25);
}
.demo h4 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  margin: 0;
}
.demo-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0;
  align-items: center;
}
.demo-controls label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-2);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.demo-controls input[type=number],
.demo-controls select {
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--border);
  color: var(--text-0);
  padding: 6px 10px;
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  width: 70px;
}
.demo-controls select { width: auto; }
.btn-mini {
  padding: 8px 14px;
  border-radius: 8px;
  background: rgba(124, 92, 255, 0.18);
  color: var(--text-0);
  border: 1px solid rgba(124, 92, 255, 0.35);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  cursor: pointer;
  font-weight: 500;
  transition: all 0.15s ease;
}
.btn-mini:hover { background: rgba(124, 92, 255, 0.32); }
.btn-mini.primary { background: linear-gradient(135deg, var(--accent-1), var(--accent-3)); color: var(--bg-0); border: none; }

.demo-stage {
  margin-top: 14px;
  padding: 24px;
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  justify-content: center;
  align-items: center;
  min-height: 120px;
}

.matrix-grid {
  display: inline-grid;
  gap: 4px;
  padding: 8px;
  background: rgba(7, 7, 13, 0.6);
  border-radius: 8px;
  border: 1px solid var(--border);
  position: relative;
}
.matrix-bracket-l,
.matrix-bracket-r {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 6px;
  pointer-events: none;
}
.matrix-bracket-l { left: -2px; border-left: 2px solid var(--accent-2); border-top: 2px solid var(--accent-2); border-bottom: 2px solid var(--accent-2); border-top-left-radius: 8px; border-bottom-left-radius: 8px; }
.matrix-bracket-r { right: -2px; border-right: 2px solid var(--accent-2); border-top: 2px solid var(--accent-2); border-bottom: 2px solid var(--accent-2); border-top-right-radius: 8px; border-bottom-right-radius: 8px; }

.m-cell {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  background: rgba(124, 92, 255, 0.08);
  border: 1px solid rgba(124, 92, 255, 0.18);
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-0);
  transition: all 0.2s ease;
  position: relative;
}
.m-cell:hover { background: rgba(124, 92, 255, 0.18); }
.m-cell.highlight { background: rgba(0, 230, 255, 0.22); border-color: var(--accent-2); color: var(--text-0); }
.m-cell.active { background: rgba(255, 92, 242, 0.22); border-color: var(--accent-3); }
.m-cell.result { background: rgba(92, 255, 160, 0.18); border-color: var(--success); }
.m-cell input {
  width: 100%;
  height: 100%;
  background: transparent;
  border: none;
  color: var(--text-0);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  text-align: center;
  outline: none;
}
.m-cell input:focus { background: rgba(124, 92, 255, 0.2); border-radius: 6px; }

.m-symbol {
  font-family: var(--font-display);
  font-size: 1.8rem;
  color: var(--accent-2);
  font-weight: 600;
  padding: 0 8px;
}

.matrix-label {
  text-align: center;
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.1rem;
  color: var(--accent-2);
  margin-top: 8px;
}

.demo-result {
  margin-top: 16px;
  padding: 14px 18px;
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-1);
  min-height: 44px;
  border-left: 3px solid var(--accent-2);
}
.demo-result .ok { color: var(--success); }
.demo-result .err { color: var(--danger); }

/* ===== Quiz ===== */
.quiz {
  margin: 28px 0;
  padding: 26px;
  background: linear-gradient(135deg, rgba(0, 230, 255, 0.06), rgba(124, 92, 255, 0.08));
  border: 1px solid rgba(0, 230, 255, 0.2);
  border-radius: var(--radius-lg);
}
.quiz-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--accent-2);
  margin-bottom: 8px;
}
.quiz h4 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  margin: 0 0 14px;
}
.quiz-question {
  color: var(--text-0);
  font-size: 1.02rem;
  margin-bottom: 16px;
}
.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.quiz-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.15s ease;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  color: var(--text-1);
}
.quiz-option:hover { border-color: var(--accent-2); background: rgba(0, 230, 255, 0.05); }
.quiz-option .key {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  background: rgba(124, 92, 255, 0.15);
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 0.78rem;
  color: var(--accent-2);
  flex-shrink: 0;
}
.quiz-option.correct {
  background: rgba(92, 255, 160, 0.12);
  border-color: var(--success);
  color: var(--text-0);
}
.quiz-option.correct .key { background: var(--success); color: var(--bg-0); }
.quiz-option.wrong {
  background: rgba(255, 85, 119, 0.1);
  border-color: var(--danger);
  color: var(--text-1);
}
.quiz-option.wrong .key { background: var(--danger); color: var(--bg-0); }
.quiz-option.disabled { pointer-events: none; opacity: 0.6; }
.quiz-option.correct.disabled, .quiz-option.wrong.disabled { opacity: 1; }

.quiz-feedback {
  margin-top: 14px;
  padding: 14px 18px;
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius);
  font-size: 0.92rem;
  color: var(--text-1);
  display: none;
}
.quiz-feedback.show { display: block; }
.quiz-feedback strong { color: var(--accent-2); }

/* ===== Glossary ===== */
.glossary {
  margin: 36px 0;
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.glossary h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  margin: 0 0 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.glossary-search {
  width: 100%;
  padding: 12px 16px;
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text-0);
  font-family: var(--font-mono);
  font-size: 0.92rem;
  margin-bottom: 18px;
}
.glossary-search:focus { outline: none; border-color: var(--accent-2); }
.glossary-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
}
.glossary-item {
  padding: 14px 16px;
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.glossary-item .term {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1rem;
  color: var(--accent-2);
  margin-bottom: 4px;
}
.glossary-item .def {
  font-size: 0.85rem;
  color: var(--text-2);
  line-height: 1.5;
}

/* ===== Next / prev nav ===== */
.tut-pager {
  display: flex;
  justify-content: space-between;
  margin-top: 60px;
  padding-top: 30px;
  border-top: 1px solid var(--border);
  gap: 16px;
}
.tut-pager a {
  text-decoration: none;
  color: var(--text-1);
  padding: 18px 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  flex: 1;
  max-width: 360px;
  transition: all 0.2s ease;
}
.tut-pager a:hover { border-color: var(--accent-2); background: rgba(0, 230, 255, 0.05); }
.tut-pager .dir { font-family: var(--font-mono); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.18em; color: var(--text-3); display: block; margin-bottom: 4px; }
.tut-pager .label { font-family: var(--font-display); font-size: 1.1rem; font-weight: 600; color: var(--text-0); }
.tut-pager .next { text-align: right; margin-left: auto; }
.tut-pager .next .dir { color: var(--accent-2); }

/* Reveal animation (gentle; elements stay visible without JS) */
.topic-card, .feature {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.js-reveal .topic-card, .js-reveal .feature {
  opacity: 0;
  transform: translateY(20px);
}
.topic-card.reveal-in, .feature.reveal-in {
  opacity: 1 !important;
  transform: translateY(0) !important;
}

/* ===== Utility ===== */
.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 12px 0;
}
.tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 4px 10px;
  border-radius: 100px;
  background: rgba(124, 92, 255, 0.12);
  color: var(--accent-2);
  border: 1px solid rgba(124, 92, 255, 0.25);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-2), var(--accent-1), var(--accent-3));
  z-index: 200;
  width: 0%;
  transition: width 0.1s ease;
}

/* =========================================
   AUTHOR PAGE
   ========================================= */

.author-hero {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 80px 28px 60px;
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 60px;
  align-items: center;
}
@media (max-width: 900px) {
  .author-hero { grid-template-columns: 1fr; padding-top: 50px; gap: 40px; }
}

.author-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent-3);
  margin-bottom: 24px;
  padding: 6px 14px;
  border: 1px solid rgba(255, 92, 242, 0.3);
  border-radius: 100px;
  background: rgba(255, 92, 242, 0.06);
}
.author-eyebrow .dot {
  width: 8px; height: 8px;
  background: var(--accent-3);
  border-radius: 50%;
  box-shadow: 0 0 12px var(--accent-3);
}

.author-name {
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 6.5vw, 4.8rem);
  font-weight: 600;
  line-height: 1.02;
  letter-spacing: -0.03em;
  margin: 0 0 22px;
  color: var(--text-0);
}
.author-name .last {
  background: linear-gradient(135deg, var(--accent-3), var(--accent-1), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.author-role {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 400;
  font-style: italic;
  color: var(--text-1);
  margin: 0 0 18px;
}
.author-role .div { color: var(--text-3); margin: 0 10px; }

.author-tagline {
  font-size: 1.08rem;
  color: var(--text-1);
  max-width: 580px;
  margin: 0 0 32px;
  line-height: 1.6;
}
.author-tagline em {
  color: var(--accent-2);
  font-style: normal;
  font-weight: 500;
}

.author-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

/* Monogram avatar */
.author-visual {
  position: relative;
  aspect-ratio: 1 / 1;
  max-width: 460px;
  margin: 0 auto;
  width: 100%;
}
.av-frame {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 32px;
  background: radial-gradient(circle at 30% 25%, rgba(124, 92, 255, 0.3), transparent 60%),
              radial-gradient(circle at 75% 80%, rgba(255, 92, 242, 0.22), transparent 60%),
              rgba(12, 12, 24, 0.7);
  border: 1px solid var(--border);
  overflow: hidden;
  display: grid;
  place-items: center;
  box-shadow: 0 30px 80px rgba(0,0,0,0.5), 0 0 60px rgba(124, 92, 255, 0.25);
}
.av-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
.av-monogram {
  position: relative;
  z-index: 2;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(6rem, 14vw, 9rem);
  line-height: 1;
  background: linear-gradient(135deg, #ffffff 0%, var(--accent-2) 40%, var(--accent-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.05em;
  filter: drop-shadow(0 8px 30px rgba(124, 92, 255, 0.5));
  animation: monogramFloat 6s ease-in-out infinite;
}
@keyframes monogramFloat {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-6px) scale(1.02); }
}
.av-corner {
  position: absolute;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-2);
  padding: 6px 12px;
  background: rgba(7, 7, 13, 0.7);
  border: 1px solid var(--border);
  border-radius: 100px;
  backdrop-filter: blur(10px);
  z-index: 3;
}
.av-corner.top-l { top: 18px; left: 18px; }
.av-corner.bot-r { bottom: 18px; right: 18px; color: var(--accent-2); }

/* Facts grid */
.facts {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 28px 40px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}
.fact {
  padding: 22px 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
  transition: all 0.25s ease;
}
.fact:hover {
  border-color: var(--border-strong);
  transform: translateY(-3px);
}
.fact::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(124, 92, 255, 0.08), transparent 60%);
  opacity: 0;
  transition: opacity 0.25s ease;
}
.fact:hover::before { opacity: 1; }
.fact-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--text-3);
  margin-bottom: 8px;
}
.fact-value {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-0);
  letter-spacing: -0.01em;
}
.fact-value a { color: var(--accent-2); text-decoration: none; }
.fact-value a:hover { text-decoration: underline; }

/* Story / split sections */
.story-section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 60px 28px;
}
.story-grid {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 60px;
  align-items: start;
}
@media (max-width: 900px) {
  .story-grid { grid-template-columns: 1fr; gap: 30px; }
}
.story-grid h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0;
  line-height: 1.15;
}
.story-grid h2 .italic {
  font-style: italic;
  font-weight: 400;
  background: linear-gradient(135deg, var(--accent-2), var(--accent-1));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.story-body p {
  color: var(--text-1);
  font-size: 1.05rem;
  line-height: 1.75;
  margin: 0 0 22px;
}
.story-body p strong { color: var(--text-0); font-weight: 600; }
.story-body p em { color: var(--accent-2); font-style: normal; font-weight: 500; }
.story-body .lead {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-style: italic;
  color: var(--text-0);
  line-height: 1.5;
  border-left: 3px solid var(--accent-3);
  padding-left: 22px;
  margin: 0 0 32px;
}

/* Contact cards */
.contact-section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 60px 28px 80px;
}
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 18px;
  margin-top: 36px;
}
.contact-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 26px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: var(--text-0);
  position: relative;
  overflow: hidden;
  transition: all 0.3s ease;
  isolation: isolate;
}
.contact-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%), rgba(124, 92, 255, 0.2), transparent 50%);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: -1;
}
.contact-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
}
.contact-card:hover::before { opacity: 1; }
.contact-card .icon-wrap {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: rgba(124, 92, 255, 0.15);
  color: var(--accent-2);
}
.contact-card.personal .icon-wrap { background: rgba(0, 230, 255, 0.15); color: var(--accent-2); }
.contact-card.work .icon-wrap { background: rgba(124, 92, 255, 0.18); color: var(--accent-1); }
.contact-card.web .icon-wrap { background: rgba(255, 92, 242, 0.15); color: var(--accent-3); }

.contact-card .cc-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--text-3);
}
.contact-card .cc-value {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-0);
  letter-spacing: -0.01em;
  word-break: break-word;
}
.contact-card .cc-hint {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-2);
  margin-top: auto;
  padding-top: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.contact-card:hover .cc-hint { color: var(--accent-2); }

/* Pillars / values */
.pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-top: 36px;
}
.pillar {
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  position: relative;
}
.pillar-num {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 600;
  background: linear-gradient(135deg, var(--accent-2), var(--accent-1));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}
.pillar h4 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0 0 8px;
  color: var(--text-0);
}
.pillar p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--text-2);
  line-height: 1.55;
}

/* CTA strip */
.cta-strip {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 60px 28px;
}
.cta-inner {
  padding: 50px;
  background: linear-gradient(135deg, rgba(124, 92, 255, 0.12), rgba(255, 92, 242, 0.08), rgba(0, 230, 255, 0.06));
  border: 1px solid rgba(124, 92, 255, 0.3);
  border-radius: var(--radius-lg);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-inner::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(124, 92, 255, 0.18), transparent 70%);
  pointer-events: none;
}
.cta-inner h2 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
  position: relative;
}
.cta-inner p {
  color: var(--text-1);
  margin: 0 auto 28px;
  max-width: 520px;
  position: relative;
}
.cta-inner .btn { position: relative; }

/* Typewriter cursor effect for tagline */
.typing-cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--accent-2);
  margin-left: 4px;
  vertical-align: text-bottom;
  animation: blink 1s steps(2) infinite;
}
@keyframes blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}


/* =========================================
   MOBILE RESPONSIVE ADDITIONS
   ========================================= */

/* ===== Mobile Nav / Hamburger ===== */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
}
.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text-0);
  border-radius: 2px;
  transition: all 0.25s ease;
  transform-origin: center;
}
.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;
  transform: scaleX(0);
}
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 768px) {
  .nav-toggle { display: flex; }

  .nav-inner { padding: 14px 18px; }

  /* Brand: hide tagline on tiny screens */
  .brand-text small { display: none; }

  /* Nav menu: slide-down drawer */
  nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(7, 7, 13, 0.97);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--border);
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
  }
  nav.open {
    max-height: 400px;
    padding: 12px 0 20px;
  }
  .nav-links {
    flex-direction: column;
    gap: 2px;
    padding: 0 18px;
  }
  .nav-links li { width: 100%; }
  .nav-links a {
    display: block;
    padding: 12px 16px;
    font-size: 1rem;
    border-radius: 10px;
  }
  .nav-cta { text-align: center; margin-top: 6px; }
}

/* ===== Hero section — mobile ===== */
@media (max-width: 768px) {
  .hero {
    padding: 40px 18px 50px;
    gap: 36px;
  }

  .hero-sub { font-size: 1rem; margin-bottom: 28px; }

  .hero-stats {
    gap: 20px;
    margin-top: 32px;
    padding-top: 24px;
  }
  .hero-stat .num { font-size: 1.5rem; }

  /* Hero visual: constrain and fix badge overflow */
  .hero-visual {
    max-width: 340px;
    width: 100%;
    overflow: visible;
  }
  .hv-badge {
    font-size: 0.65rem;
    padding: 6px 10px;
    gap: 6px;
    white-space: nowrap;
  }
  /* Reposition badges so they don't overflow the viewport */
  .hv-1 { top: 5%; left: 4%; }
  .hv-2 { bottom: 8%; right: 4%; }
  .hv-3 { bottom: 38%; left: 4%; }
}

@media (max-width: 480px) {
  .hero { padding: 32px 16px 40px; }

  h1.hero-title { font-size: 2.1rem; }

  .hero-cta { gap: 10px; }
  .btn { padding: 12px 20px; font-size: 0.9rem; }

  /* Hide hero badges on very small screens to avoid clutter */
  .hv-badge { display: none; }

  .hero-stats { gap: 16px; flex-wrap: wrap; }
}

/* ===== Sections — mobile ===== */
@media (max-width: 768px) {
  .section { padding: 56px 18px; }

  .section-head { flex-direction: column; align-items: flex-start; gap: 16px; margin-bottom: 32px; }

  h2.section-title { font-size: 1.7rem; }
}

/* ===== Topic grid — mobile ===== */
@media (max-width: 480px) {
  .topic-grid { grid-template-columns: 1fr; gap: 16px; }
  .topic-card { padding: 22px 18px; }
  .topic-icon { width: 48px; height: 48px; margin-bottom: 16px; font-size: 1.4rem; }
}

/* ===== Features row — mobile ===== */
@media (max-width: 480px) {
  .features { grid-template-columns: 1fr; gap: 14px; }
  .feature { padding: 20px 18px; }
}

/* ===== CTA strip — mobile ===== */
@media (max-width: 768px) {
  .cta-inner { padding: 36px 24px; }
}
@media (max-width: 480px) {
  .cta-inner { padding: 28px 18px; }
  .cta-inner h2 { font-size: 1.5rem; }
}

/* ===== Footer — mobile ===== */
@media (max-width: 480px) {
  .footer {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 18px 30px;
  }
}

/* ===== Tutorial page — mobile ===== */
@media (max-width: 768px) {
  .tutorial-wrap { padding: 24px 18px 60px; gap: 0; }

  /* Sidebar becomes a collapsible at top on mobile */
  .tut-sidebar {
    position: static;
    max-height: none;
    overflow: visible;
    padding: 18px;
    margin-bottom: 28px;
  }

  .lesson { margin-bottom: 56px; }
  .lesson h2 { font-size: 1.5rem; }
}

/* Matrix demo cells — shrink on mobile */
@media (max-width: 600px) {
  .m-cell {
    width: 38px;
    height: 38px;
    font-size: 0.82rem;
  }
  .m-cell input { font-size: 0.82rem; }

  .demo { padding: 18px 14px; }
  .demo-stage {
    padding: 16px 10px;
    gap: 10px;
    overflow-x: auto;
  }

  /* Allow horizontal scroll for large matrix layouts */
  .demo-stage > * { flex-shrink: 0; }
}

@media (max-width: 480px) {
  .tut-hero h1 { font-size: 2rem; }
  .tut-hero .lead { font-size: 1rem; }
  .tut-hero-meta { gap: 14px; font-size: 0.72rem; }

  .callout { padding: 14px 16px; gap: 10px; }
  .quiz { padding: 18px 16px; }
  .quiz-option { padding: 12px 14px; font-size: 0.85rem; }

  .tut-pager { flex-direction: column; gap: 12px; }
  .tut-pager a { max-width: 100%; }
}

/* ===== Author page — mobile ===== */
@media (max-width: 768px) {
  .author-hero { padding: 48px 18px 40px; gap: 32px; }
  .author-visual { max-width: 300px; }
  .av-monogram { font-size: 5rem; }

  .facts { padding: 0 18px 32px; }

  .story-section { padding: 40px 18px; }
  .contact-section { padding: 40px 18px 60px; }

  .cta-strip { padding: 40px 18px; }
}

@media (max-width: 480px) {
  .author-name { font-size: 2.4rem; }
  .author-role { font-size: 1.1rem; }

  .contact-grid { grid-template-columns: 1fr; }
  .pillars { grid-template-columns: 1fr; }
}

/* ===== General touch improvements ===== */
@media (hover: none) {
  /* Remove hover-only effects that don't work on touch */
  .topic-card:hover { transform: none; }
  .fact:hover { transform: none; }
  .contact-card:hover { transform: none; }
  .btn-primary:hover { transform: none; }

  /* Increase tap target sizes */
  .nav-links a { padding: 12px 16px; }
  .quiz-option { padding: 16px 18px; }
  .tut-toc a { padding: 12px 14px; }
}

/* ===== Reduced motion ===== */
@media (prefers-reduced-motion: reduce) {
  .bg-symbols span,
  .hero-eyebrow .dot,
  .av-monogram,
  .typing-cursor {
    animation: none;
  }
  * { transition-duration: 0.01ms !important; }
}

/* ===== Prevent horizontal overflow globally ===== */
@media (max-width: 768px) {
  .bg-grid { background-size: 40px 40px; }
  .nav { position: sticky; }
}