/* ===========================================
   AI Course Design System v2.0
   - Dark mode default, light mode toggle
   - Glass morphism + gradient AI accents
   - Smooth animations + scroll reveals
   =========================================== */

/* CSS Variables - Dark theme (default) */
:root {
  --bg: #0a0b14;
  --bg-2: #0f1120;
  --bg-3: #161830;
  --surface: #1a1d35;
  --surface-2: #20243f;
  --surface-3: #2a2f50;
  --line: rgba(255, 255, 255, 0.08);
  --line-2: rgba(255, 255, 255, 0.12);
  --ink: #f4f5fb;
  --ink-2: #c8cce0;
  --ink-3: #9aa0bd;
  --muted: #6b7295;
  --brand: #6366f1;
  --brand-2: #8b5cf6;
  --brand-3: #a855f7;
  --accent: #06b6d4;
  --accent-2: #22d3ee;
  --teal: #14b8a6;
  --green: #10b981;
  --pink: #ec4899;
  --orange: #f59e0b;
  --red: #ef4444;
  --gradient-1: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
  --gradient-2: linear-gradient(135deg, #06b6d4 0%, #6366f1 100%);
  --gradient-3: linear-gradient(135deg, #ec4899 0%, #f59e0b 100%);
  --gradient-glow: radial-gradient(circle, rgba(139, 92, 246, 0.4), transparent 60%);
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 48px rgba(0, 0, 0, 0.5);
  --glow: 0 0 30px rgba(139, 92, 246, 0.3);
  --radius: 14px;
  --radius-lg: 20px;
  --font: 'Noto Sans Thai', 'Inter', system-ui, -apple-system, sans-serif;
  --mono: 'SF Mono', Monaco, 'Cascadia Code', monospace;
}

/* Light theme override */
[data-theme="light"] {
  --bg: #fafbfd;
  --bg-2: #f4f5fb;
  --bg-3: #eef0f7;
  --surface: #ffffff;
  --surface-2: #f7f8fc;
  --surface-3: #eef0f7;
  --line: rgba(15, 23, 42, 0.08);
  --line-2: rgba(15, 23, 42, 0.12);
  --ink: #0a0f1f;
  --ink-2: #3b4358;
  --ink-3: #5a6079;
  --muted: #6b7388;
  --shadow: 0 4px 24px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 12px 48px rgba(15, 23, 42, 0.1);
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background .4s, color .4s;
}
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
img { max-width: 100%; }

/* ============ GLOBAL ANIMATIONS ============ */
@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-20px); }
}
@keyframes pulse {
  0%, 100% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.05); }
}
@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}
@keyframes gradient-shift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}
@keyframes fade-up {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes typing {
  0%, 60%, 100% { opacity: 0.3; }
  30% { opacity: 1; }
}
@keyframes blob {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(40px, -30px) scale(1.1); }
  66% { transform: translate(-30px, 40px) scale(0.9); }
}
@keyframes orbit {
  from { transform: rotate(0deg) translateX(120px) rotate(0deg); }
  to { transform: rotate(360deg) translateX(120px) rotate(-360deg); }
}

/* Reveal on scroll */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .8s ease, transform .8s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============ NAV ============ */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 11, 20, 0.7);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
  transition: background .4s;
}
[data-theme="light"] .nav { background: rgba(255, 255, 255, 0.85); }

.nav-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 14px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--gradient-1);
  background-size: 200% 200%;
  animation: gradient-shift 6s ease infinite;
  display: grid;
  place-items: center;
  color: white;
  font-size: 17px;
  font-weight: 800;
  box-shadow: var(--glow);
  position: relative;
}
.brand-mark::after {
  content: '';
  position: absolute;
  inset: -2px;
  border-radius: 11px;
  background: var(--gradient-1);
  opacity: 0.4;
  filter: blur(8px);
  z-index: -1;
}

.nav-links {
  display: flex;
  gap: 4px;
  align-items: center;
}
.nav-links a {
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-2);
  transition: all .2s;
  position: relative;
}
.nav-links a:hover { color: var(--ink); background: var(--surface-2); }
.nav-links a.active {
  color: var(--accent-2);
  background: rgba(6, 182, 212, 0.1);
}
.nav-links a.cta {
  background: var(--gradient-1);
  background-size: 200% 200%;
  color: white !important;
  padding: 9px 18px !important;
  border-radius: 10px;
  font-weight: 600;
  animation: gradient-shift 6s ease infinite;
}
.nav-links a.cta:hover { transform: translateY(-1px); box-shadow: var(--glow); }

/* Theme toggle */
.theme-toggle {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--surface-2);
  display: grid;
  place-items: center;
  color: var(--ink-2);
  font-size: 16px;
  transition: all .2s;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent-2); transform: rotate(15deg); }

/* ============ HERO ============ */
.hero {
  position: relative;
  padding: 100px 28px 90px;
  overflow: hidden;
  min-height: 80vh;
  display: flex;
  align-items: center;
}
.hero-inner {
  max-width: 1280px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
  width: 100%;
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}
.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.5;
  animation: blob 14s ease-in-out infinite;
}
.blob.b1 { width: 500px; height: 500px; background: var(--brand); top: -100px; left: -100px; }
.blob.b2 { width: 400px; height: 400px; background: var(--accent); bottom: -100px; right: 10%; animation-delay: -7s; }
.blob.b3 { width: 350px; height: 350px; background: var(--pink); top: 30%; right: -100px; animation-delay: -3s; opacity: 0.3; }

[data-theme="light"] .blob { opacity: 0.18; }

.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(139, 92, 246, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(139, 92, 246, 0.05) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black, transparent);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black, transparent);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  background: rgba(99, 102, 241, 0.12);
  color: var(--accent-2);
  border: 1px solid rgba(6, 182, 212, 0.2);
  margin-bottom: 20px;
}
.eyebrow .dot {
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent);
  animation: pulse 2s ease infinite;
}

h1.hero-title {
  font-size: clamp(38px, 5.5vw, 64px);
  line-height: 1.1;
  margin: 0 0 22px;
  font-weight: 800;
  letter-spacing: -0.03em;
}
h1.hero-title .grad {
  background: var(--gradient-1);
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: gradient-shift 8s ease infinite;
}
.hero-sub {
  font-size: 19px;
  color: var(--ink-2);
  margin: 0 0 32px;
  max-width: 580px;
  line-height: 1.65;
}

.hero-cta {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 24px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 15px;
  border: none;
  cursor: pointer;
  transition: all .2s;
  text-decoration: none;
}
.btn-primary {
  background: var(--gradient-1);
  background-size: 200% 200%;
  color: white;
  animation: gradient-shift 6s ease infinite;
  box-shadow: var(--glow);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 0 40px rgba(139, 92, 246, 0.5); }
.btn-ghost {
  background: var(--surface);
  color: var(--ink);
  border: 1px solid var(--line);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent-2); }

.hero-stats {
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
}
.hero-stat .num {
  font-size: 28px;
  font-weight: 800;
  background: var(--gradient-2);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1;
}
.hero-stat .lbl {
  font-size: 13px;
  color: var(--muted);
  margin-top: 4px;
  font-weight: 500;
}

/* ============ AI CHAT DEMO (Hero visual) ============ */
.ai-demo {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(10px);
}
.ai-demo::before {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-lg);
  background: var(--gradient-1);
  opacity: 0.3;
  filter: blur(20px);
  z-index: -1;
}
.demo-head {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}
.demo-head .dots { display: flex; gap: 6px; }
.demo-head .dots span {
  width: 11px;
  height: 11px;
  border-radius: 50%;
}
.demo-head .dots span:nth-child(1) { background: var(--red); }
.demo-head .dots span:nth-child(2) { background: var(--orange); }
.demo-head .dots span:nth-child(3) { background: var(--green); }
.demo-head .demo-label {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--muted);
  margin-left: 8px;
}
.demo-head .live {
  margin-left: auto;
  font-size: 12px;
  color: var(--green);
  display: flex;
  align-items: center;
  gap: 6px;
}
.demo-head .live::before {
  content: '';
  width: 6px;
  height: 6px;
  background: var(--green);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

.bubble {
  padding: 12px 16px;
  border-radius: 14px;
  max-width: 85%;
  font-size: 14px;
  margin-bottom: 10px;
  animation: fade-up .4s ease backwards;
}
.bubble.you {
  background: var(--surface-2);
  color: var(--ink);
  border-bottom-left-radius: 4px;
  margin-right: auto;
}
.bubble.ai {
  background: var(--gradient-1);
  background-size: 200% 200%;
  color: white;
  border-bottom-right-radius: 4px;
  margin-left: auto;
  animation: fade-up .4s ease backwards, gradient-shift 6s ease infinite;
}
.bubble.ai b { font-weight: 700; }
.bubble .typing {
  display: inline-flex;
  gap: 4px;
  margin-left: 6px;
}
.bubble .typing span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  animation: typing 1.4s infinite;
}
.bubble .typing span:nth-child(2) { animation-delay: .2s; }
.bubble .typing span:nth-child(3) { animation-delay: .4s; }

/* ============ SECTION ============ */
.section {
  padding: 90px 28px;
  position: relative;
}
.section-alt { background: var(--bg-2); }
.section-inner {
  max-width: 1280px;
  margin: 0 auto;
}
.section-head {
  text-align: center;
  margin-bottom: 56px;
}
.section-head .kicker {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  color: var(--accent-2);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 12px;
}
.section-head h2 {
  font-size: clamp(30px, 4.2vw, 46px);
  margin: 0 0 14px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
}
.section-head h2 .grad {
  background: var(--gradient-1);
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: gradient-shift 8s ease infinite;
}
.section-head p {
  font-size: 17px;
  color: var(--ink-2);
  margin: 0 auto;
  max-width: 640px;
}

/* ============ CARDS ============ */
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform .3s, border-color .3s, box-shadow .3s;
}
.card:hover {
  transform: translateY(-4px);
  border-color: var(--line-2);
  box-shadow: var(--shadow);
}
.card .card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-size: 24px;
  margin-bottom: 16px;
  background: var(--gradient-1);
  background-size: 200% 200%;
  animation: gradient-shift 6s ease infinite;
  color: white;
}
.card h3 { font-size: 19px; margin: 0 0 8px; font-weight: 700; }
.card p { font-size: 14.5px; color: var(--ink-2); margin: 0; line-height: 1.65; }

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 24px;
}

/* Glass card variant */
.glass {
  background: rgba(26, 29, 53, 0.5);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-lg);
  padding: 32px;
}
[data-theme="light"] .glass {
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(15, 23, 42, 0.06);
}

/* ============ TIPS / CHAPTERS ============ */
.tips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
}
.tip-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
  position: relative;
  overflow: hidden;
  transition: transform .3s, border-color .3s, box-shadow .3s;
}
.tip-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--tip-accent, var(--brand));
}
.tip-card:hover {
  transform: translateY(-4px);
  border-color: var(--tip-accent, var(--brand));
  box-shadow: var(--shadow);
}
.tip-card .tip-num {
  display: inline-grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--tip-bg, rgba(99, 102, 241, 0.12));
  color: var(--tip-accent, var(--brand));
  font-weight: 800;
  font-size: 16px;
  margin-bottom: 14px;
}
.tip-card .tip-emoji { font-size: 28px; display: block; margin-bottom: 10px; }
.tip-card h4 { font-size: 19px; margin: 0 0 10px; font-weight: 700; }
.tip-card p { font-size: 14.5px; color: var(--ink-2); margin: 0 0 16px; line-height: 1.65; }

.tip-card.c1 { --tip-accent: #6366f1; --tip-bg: rgba(99, 102, 241, 0.12); }
.tip-card.c2 { --tip-accent: #06b6d4; --tip-bg: rgba(6, 182, 212, 0.12); }
.tip-card.c3 { --tip-accent: #f59e0b; --tip-bg: rgba(245, 158, 11, 0.12); }
.tip-card.c4 { --tip-accent: #ec4899; --tip-bg: rgba(236, 72, 153, 0.12); }
.tip-card.c5 { --tip-accent: #10b981; --tip-bg: rgba(16, 185, 129, 0.12); }
.tip-card.c6 { --tip-accent: #8b5cf6; --tip-bg: rgba(139, 92, 246, 0.12); }

/* ============ FOOTER ============ */
.footer {
  padding: 50px 28px 30px;
  border-top: 1px solid var(--line);
  background: var(--bg-2);
  font-size: 14px;
}
.footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
}
.footer .brand { color: var(--ink); }
.footer-links { display: flex; gap: 4px; flex-wrap: wrap; }
.footer-links a {
  padding: 6px 12px;
  border-radius: 6px;
  color: var(--ink-2);
  font-size: 13.5px;
}
.footer-links a:hover { color: var(--accent-2); background: var(--surface); }

/* ============ CHAT WIDGET (floating) ============ */
.chat-fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 99;
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: var(--gradient-1);
  background-size: 200% 200%;
  animation: gradient-shift 6s ease infinite;
  border: none;
  color: white;
  font-size: 26px;
  cursor: pointer;
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.4);
  transition: transform .2s;
}
.chat-fab:hover { transform: scale(1.08); }
.chat-fab .ping {
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 2px solid var(--brand);
  animation: pulse 2s infinite;
}

.chat-panel {
  position: fixed;
  bottom: 100px;
  right: 24px;
  z-index: 98;
  width: 360px;
  max-width: calc(100vw - 48px);
  height: 500px;
  max-height: 70vh;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  display: none;
  flex-direction: column;
  overflow: hidden;
  backdrop-filter: blur(20px);
}
.chat-panel.open { display: flex; animation: fade-up .3s ease; }
.chat-head {
  padding: 16px 20px;
  background: var(--gradient-1);
  background-size: 200% 200%;
  animation: gradient-shift 6s ease infinite;
  color: white;
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 14px;
}
.chat-head .avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: rgba(255,255,255,0.2);
  display: grid;
  place-items: center;
  font-size: 16px;
}
.chat-head .close {
  margin-left: auto;
  background: rgba(255,255,255,0.15);
  border: none;
  color: white;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 14px;
}
.chat-body {
  flex: 1;
  padding: 16px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.chat-msg {
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 13.5px;
  max-width: 85%;
  line-height: 1.5;
}
.chat-msg.bot {
  background: var(--surface-2);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}
.chat-msg.user {
  background: var(--gradient-1);
  background-size: 200% 200%;
  color: white;
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}
.chat-quick {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.chat-quick button {
  font-size: 12px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  color: var(--ink-2);
}
.chat-quick button:hover { background: var(--surface-3); color: var(--ink); }

/* ============ FORM ELEMENTS ============ */
input, textarea, select {
  font-family: inherit;
  font-size: 14.5px;
  padding: 12px 16px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--surface-2);
  color: var(--ink);
  outline: none;
  transition: border-color .2s, box-shadow .2s;
  width: 100%;
}
input:focus, textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.15);
}
textarea { resize: vertical; min-height: 100px; line-height: 1.6; }
label { font-size: 14px; font-weight: 600; color: var(--ink-2); display: block; margin-bottom: 8px; }

/* ============ PROMPT CODE BLOCK ============ */
.code-block {
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--ink-2);
  overflow-x: auto;
  white-space: pre-wrap;
  position: relative;
}
[data-theme="light"] .code-block { background: var(--bg-2); }
.code-block .cmt { color: var(--muted); font-style: italic; }
.code-block .kw { color: var(--pink); }
.code-block .str { color: var(--green); }
.code-block .var { color: var(--orange); }

/* ============ UTILS ============ */
.text-grad {
  background: var(--gradient-1);
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: gradient-shift 8s ease infinite;
}
.text-grad-2 {
  background: var(--gradient-2);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.badge {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.5px;
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent-2);
  border: 1px solid rgba(6, 182, 212, 0.2);
}

.divider {
  height: 1px;
  background: var(--line);
  margin: 60px 0;
}

.tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 3px 8px;
  border-radius: 4px;
  background: var(--surface-2);
  color: var(--muted);
  margin-right: 4px;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 960px) {
  .hero { padding: 60px 20px 70px; min-height: auto; }
  .hero-inner { grid-template-columns: 1fr; gap: 50px; }
  .section { padding: 60px 20px; }
  .nav-links a:not(.cta) { display: none; }
  .nav-inner { padding: 12px 20px; }
  .footer-inner { flex-direction: column; text-align: center; }
}
@media (max-width: 560px) {
  h1.hero-title { font-size: 36px; }
  .hero-cta { flex-direction: column; align-items: stretch; }
  .btn { justify-content: center; }
  .hero-stats { gap: 20px; }
  .chat-panel { right: 12px; left: 12px; width: auto; }
  .chat-fab { right: 16px; bottom: 16px; }
}