/* ===================================================================
   KHB.HK — Enterprise AI Influence Platform
   Global stylesheet (single file)
   Style: Deep dark + tech blue + KHB orange accent
   =================================================================== */

/* === 1. CSS Variables ============================================ */
/* KHB Group V2.6 Design System — Graphite + Blue + Orange */
:root,
:root[data-theme="dark"] {
  /* Backgrounds — Graphite palette */
  --bg-void: #111418;
  --bg-surface: #151A21;
  --bg-elevated: #1A202C;
  --bg-card-hover: #202838;
  --bg-footer: #0D1117;
  --bg-overlay: rgba(17, 20, 24, 0.85);

  /* Borders */
  --border-subtle: #263140;
  --border-strong: #2D3748;
  --border-blue: rgba(59, 130, 246, 0.30);

  /* Text — White / Gray hierarchy */
  --text-primary: #FFFFFF;
  --text-secondary: #CBD5E1;
  --text-muted: #94A3B8;
  --text-inverse: #111418;

  /* Brand — AI Blue */
  --brand-blue: #3B82F6;
  --brand-blue-light: #60A5FA;
  --brand-blue-dark: #2563EB;

  /* Accent — CTA Orange */
  --accent-orange: #F97316;
  --accent-orange-dark: #EA580C;

  /* Gradients — subtle */
  --gradient-blue: linear-gradient(135deg, #3B82F6 0%, #60A5FA 100%);
  --gradient-hero: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(59, 130, 246, 0.12) 0%, transparent 60%),
                   radial-gradient(ellipse 60% 50% at 80% 20%, rgba(249, 115, 22, 0.06) 0%, transparent 50%);

  /* Shadows — no glow per V2.6 */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.30);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.40);
  --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.50);
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.25), 0 0 0 1px var(--border-subtle);

  /* Typography */
  --font-display: 'Sora', 'Noto Sans HK', system-ui, sans-serif;
  --font-body: 'IBM Plex Sans', 'Noto Sans HK', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, monospace;

  /* Spacing scale (4px base) */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;
  --space-24: 96px;
  --space-32: 128px;

  /* Radii */
  --radius-sm: 4px;
  --radius: 6px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  --radius-full: 9999px;

  /* Container */
  --container-max: 1280px;
  --container-pad: 24px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition: 250ms ease;
  --transition-slow: 400ms ease;
}

:root[data-theme="light"] {
  --bg-void: #F8FAFC;
  --bg-surface: #FFFFFF;
  --bg-elevated: #F1F5F9;
  --bg-card-hover: #E2E8F0;
  --bg-footer: #0F172A;
  --bg-overlay: rgba(255, 255, 255, 0.92);

  --border-subtle: #E2E8F0;
  --border-strong: #CBD5E1;
  --border-blue: rgba(59, 130, 246, 0.30);

  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #64748B;
  --text-inverse: #FFFFFF;

  --gradient-hero: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(59, 130, 246, 0.08) 0%, transparent 60%),
                   radial-gradient(ellipse 60% 50% at 80% 20%, rgba(249, 115, 22, 0.04) 0%, transparent 50%);

  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.10);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.12);
  --shadow-card: 0 4px 20px rgba(15, 23, 42, 0.06), 0 0 0 1px var(--border-subtle);
}

/* === 2. Reset & Base ============================================= */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background: var(--bg-void);
  color: var(--text-primary);
  line-height: 1.65;
  font-weight: 400;
  min-height: 100vh;
  overflow-x: hidden;
}

/* No-load-animation guarantee: nothing animates on initial render */
img, svg, canvas { display: block; max-width: 100%; }
img { height: auto; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
input, textarea, select { font-family: inherit; font-size: inherit; }
ul, ol { list-style: none; }
hr { border: none; border-top: 1px solid var(--border-subtle); }

::selection { background: var(--brand-blue); color: #fff; }

:focus-visible {
  outline: 2px solid var(--brand-blue-light);
  outline-offset: 2px;
  border-radius: 4px;
}

/* Scrollbar */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-void); }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--brand-blue); }

/* === 3. Typography ============================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

h1 { font-size: clamp(1.75rem, 4vw, 2.75rem); font-weight: 800; }
h2 { font-size: clamp(1.5rem, 3vw, 2.125rem); }
h3 { font-size: clamp(1.25rem, 2vw, 1.375rem); }
h4 { font-size: 1.25rem; font-weight: 600; }
h5 { font-size: 1.125rem; font-weight: 600; }
h6 { font-size: 1rem; font-weight: 600; }

p { color: var(--text-secondary); }

.lead { font-size: 1.125rem; line-height: 1.7; color: var(--text-secondary); }
.text-gradient-blue {
  background: var(--gradient-blue);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.text-gradient-orange {
  color: var(--accent-orange);
}
.text-mono { font-family: var(--font-mono); }

/* === 4. Layout ================================================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}

.section {
  padding: clamp(64px, 9vw, 128px) 0;
  position: relative;
}

.section-sm { padding: clamp(48px, 6vw, 80px) 0; }
.section-lg { padding: clamp(96px, 12vw, 160px) 0; }

.section-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-strong), transparent);
  margin: 0;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto clamp(40px, 6vw, 72px);
}

.section-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: rgba(59, 130, 246, 0.08);
  border: 1px solid var(--border-blue);
  color: var(--brand-blue);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  margin-bottom: 20px;
  font-family: var(--font-mono);
}

.section-eyebrow::before {
  content: '';
  width: 6px; height: 6px;
  background: var(--brand-blue);
  border-radius: 50%;
}

.section-title {
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Grids */
.grid { display: grid; gap: var(--space-6); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-auto { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }

.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-col { flex-direction: column; }
.gap-2 { gap: 8px; } .gap-3 { gap: 12px; } .gap-4 { gap: 16px; } .gap-6 { gap: 24px; } .gap-8 { gap: 32px; }

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* === 5. Components ============================================= */

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1;
  border-radius: var(--radius);
  transition: background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  min-height: 44px;
}
.btn svg { width: 16px; height: 16px; }

.btn-primary {
  background: var(--brand-blue);
  color: #fff;
}
.btn-primary:hover {
  background: var(--brand-blue-dark);
  transform: translateY(-1px);
}

.btn-cta {
  background: var(--accent-orange);
  color: #fff;
}
.btn-cta:hover {
  background: var(--accent-orange-dark);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border-strong);
}
.btn-ghost:hover {
  background: var(--bg-elevated);
  border-color: var(--brand-blue);
  color: var(--text-primary);
}

.btn-outline {
  background: transparent;
  color: var(--brand-blue);
  border-color: var(--border-blue);
}
.btn-outline:hover {
  background: rgba(59, 130, 246, 0.08);
}

.btn-lg { padding: 16px 28px; font-size: 1rem; }
.btn-sm { padding: 8px 16px; font-size: 0.8125rem; min-height: 32px; }
.btn-block { width: 100%; }

/* --- Badge / Chip --- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-secondary);
}
.badge-blue { background: rgba(59, 130, 246, 0.10); border-color: var(--border-blue); color: var(--brand-blue); }
.badge-orange { background: rgba(249, 115, 22, 0.10); border-color: rgba(249, 115, 22, 0.30); color: var(--accent-orange); }

/* --- Card --- */
.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: border-color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast);
  position: relative;
  overflow: hidden;
}
.card-hover:hover {
  transform: translateY(-4px);
  border-color: var(--brand-blue);
  background: var(--bg-card-hover);
}
.card-glow::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top right, rgba(59, 130, 246, 0.06), transparent 60%);
  pointer-events: none;
}
.card-icon {
  width: 48px; height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(59, 130, 246, 0.10);
  color: var(--brand-blue);
  margin-bottom: 20px;
}
.card-icon svg { width: 24px; height: 24px; }
.card-icon.orange { background: rgba(249, 115, 22, 0.10); color: var(--accent-orange); }
.card-title { font-size: 1.125rem; font-weight: 600; margin-bottom: 8px; color: var(--text-primary); }
.card-text { color: var(--text-secondary); font-size: 0.9375rem; line-height: 1.6; }

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: var(--bg-overlay);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  transition: background var(--transition);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}
.nav-brand img { width: 50px; height: auto; }
.nav-brand sup {
  font-size: 0.5em;
  position: relative;
  top: -0.55em;
  margin-left: 1px;
  color: var(--accent-orange);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-link {
  padding: 8px 14px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius);
  transition: color var(--transition-fast), background var(--transition-fast);
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.nav-link:hover, .nav-link.active {
  color: var(--brand-blue);
  background: var(--bg-elevated);
}
.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -1px; left: 14px; right: 14px;
  height: 2px;
  background: var(--brand-blue);
  border-radius: 1px;
}
.nav-cta {
  display: flex;
  align-items: center;
  gap: 10px;
}
.nav-toggle {
  display: none;
  width: 40px; height: 40px;
  border-radius: var(--radius);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  align-items: center;
  justify-content: center;
}
.nav-toggle svg { width: 20px; height: 20px; }

/* Dropdown */
.has-dropdown { position: relative; }
.dropdown {
  position: absolute;
  top: 100%; left: 0;
  min-width: 220px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: 8px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
  margin-top: 8px;
}
.has-dropdown:hover .dropdown,
.has-dropdown:focus-within .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.dropdown-link {
  display: block;
  padding: 10px 12px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast), color var(--transition-fast);
}
.dropdown-link:hover {
  background: var(--bg-surface);
  color: var(--brand-blue);
}
.dropdown-link .coming {
  margin-left: 6px;
  font-size: 0.6875rem;
  color: var(--text-muted);
  background: var(--bg-surface);
  padding: 2px 6px;
  border-radius: var(--radius-full);
}

/* --- Theme & Lang toggles --- */
.theme-toggle, .lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 36px;
  padding: 0 10px;
  border-radius: var(--radius-full);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  font-size: 0.8125rem;
  color: var(--text-secondary);
  transition: background var(--transition-fast), border-color var(--transition-fast);
}
.theme-toggle:hover, .lang-switch:hover {
  border-color: var(--border-blue);
  color: var(--text-primary);
}
.theme-toggle svg { width: 16px; height: 16px; }
.lang-switch .lang-btn {
  padding: 2px 8px;
  border-radius: var(--radius-full);
  color: var(--text-muted);
  font-weight: 500;
  transition: background var(--transition-fast), color var(--transition-fast);
}
.lang-switch .lang-btn.active {
  background: var(--brand-blue);
  color: #fff;
}

/* --- Form --- */
.form-group { margin-bottom: 18px; }
.form-label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 6px;
}
.form-label .req { color: var(--accent-orange); }
.input, .textarea, .select {
  width: 100%;
  padding: 12px 14px;
  background: var(--bg-void);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.9375rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.input::placeholder, .textarea::placeholder { color: var(--text-muted); }
.input:focus, .textarea:focus, .select:focus {
  outline: none;
  border-color: var(--brand-blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}
.textarea { min-height: 120px; resize: vertical; }

/* --- Toast --- */
.toast {
  position: fixed;
  bottom: 24px; left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: var(--bg-elevated);
  border: 1px solid var(--border-blue);
  border-radius: var(--radius-md);
  padding: 14px 20px;
  color: var(--text-primary);
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  opacity: 0;
  transition: transform var(--transition), opacity var(--transition);
  display: flex;
  align-items: center;
  gap: 10px;
}
.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}
.toast svg { width: 18px; height: 18px; color: var(--accent-orange); }

/* === 6. Page-specific ========================================== */

/* --- Hero --- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 0 80px;
  overflow: hidden;
  background: var(--bg-void);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background: var(--gradient-hero);
  z-index: 0;
}
.hero-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  opacity: 0.5;
}
.hero-inner {
  position: relative;
  z-index: 2;
  max-width: 920px;
  margin: 0 auto;
  padding: 0 var(--container-pad);
}
.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
}
.hero-eyebrow .dot {
  width: 6px; height: 6px;
  background: var(--accent-orange);
  border-radius: 50%;
}
.hero-title {
  font-size: clamp(2rem, 5vw, 2.75rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}
.hero-subtitle {
  font-size: clamp(1.0625rem, 1.6vw, 1.25rem);
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 680px;
  margin: 0 auto 36px;
}
.hero-cta {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 64px;
}
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  max-width: 760px;
  margin: 0 auto;
  padding: 28px 0;
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}
.hero-stat-num {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  color: var(--brand-blue);
  line-height: 1;
  margin-bottom: 6px;
}
.hero-stat-label {
  font-size: 0.8125rem;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

/* --- AI Models Strip --- */
.ai-models {
  padding: 48px 0;
  border-bottom: 1px solid var(--border-subtle);
}
.ai-models-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
}
.ai-models-label {
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}
.ai-models-list {
  display: flex;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}
.ai-model-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.9375rem;
  opacity: 0.8;
  transition: opacity var(--transition-fast), color var(--transition-fast);
}
.ai-model-item:hover { opacity: 1; color: var(--text-primary); }
.ai-model-item .dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--brand-blue);
}

/* --- Influence Card --- */
.influence-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.influence-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.influence-ring {
  width: 120px; height: 120px;
  margin: 0 auto 20px;
  position: relative;
}
.influence-ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.influence-ring .track { stroke: var(--border-subtle); }
.influence-ring .fill {
  stroke: url(#grad-blue);
  stroke-linecap: round;
  transition: stroke-dashoffset 1s ease;
}
.influence-ring.orange .fill { stroke: url(#grad-orange); }
.influence-ring .num {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-primary);
}
.influence-card .label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 4px;
}
.influence-card .desc {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* --- Product Matrix --- */
.product-matrix {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.product-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px;
  position: relative;
  transition: transform var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast);
}
.product-card:hover {
  transform: translateY(-4px);
  border-color: var(--brand-blue);
  background: var(--bg-card-hover);
}
.product-card.featured {
  background: linear-gradient(180deg, rgba(59, 130, 246, 0.04), var(--bg-elevated));
  border-color: var(--border-blue);
}
.product-tier {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--brand-blue);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: rgba(59, 130, 246, 0.08);
  border: 1px solid var(--border-blue);
  margin-bottom: 16px;
}
.product-card.featured .product-tier {
  background: rgba(249, 115, 22, 0.10);
  color: var(--accent-orange);
  border-color: rgba(249, 115, 22, 0.30);
}
.product-name {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
}
.product-desc {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.6;
  margin-bottom: 20px;
  min-height: 48px;
}
.product-features {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 24px;
}
.product-feature {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}
.product-feature svg {
  width: 14px; height: 14px;
  color: var(--brand-blue);
  flex-shrink: 0;
  margin-top: 3px;
}

/* --- KAIF Timeline --- */
.kaif-timeline {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 12px;
  position: relative;
  margin-top: 48px;
}
.kaif-timeline::before {
  content: '';
  position: absolute;
  top: 24px; left: 7%; right: 7%;
  height: 2px;
  background: linear-gradient(90deg, var(--brand-blue-dark), var(--brand-blue), var(--accent-orange));
  z-index: 0;
}
.kaif-step {
  text-align: center;
  position: relative;
  z-index: 1;
}
.kaif-num {
  width: 48px; height: 48px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: var(--bg-elevated);
  border: 2px solid var(--brand-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--brand-blue);
  font-size: 1rem;
  box-shadow: 0 0 0 6px var(--bg-void);
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}
.kaif-step:hover .kaif-num {
  transform: scale(1.05);
}
.kaif-step:last-child .kaif-num {
  border-color: var(--accent-orange);
  color: var(--accent-orange);
}
.kaif-name {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 4px;
}
.kaif-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* --- AI Board Agents --- */
.agent-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 16px;
}
.agent-card {
  text-align: center;
  padding: 24px 12px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}
.agent-card:hover {
  transform: translateY(-4px);
  border-color: var(--brand-blue);
}
.agent-avatar {
  width: 72px; height: 72px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--brand-blue-dark), var(--brand-blue));
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  color: #fff;
  border: 2px solid var(--border-strong);
  position: relative;
}
.agent-avatar::after {
  content: '';
  position: absolute;
  bottom: 2px; right: 2px;
  width: 12px; height: 12px;
  background: #10B981;
  border: 2px solid var(--bg-elevated);
  border-radius: 50%;
}
.agent-role {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--brand-blue);
  margin-bottom: 4px;
}
.agent-name {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* --- CTA Banner --- */
.cta-banner {
  position: relative;
  padding: clamp(64px, 8vw, 96px) 0;
  text-align: center;
  background:
    radial-gradient(ellipse 60% 80% at 50% 50%, rgba(59, 130, 246, 0.10) 0%, transparent 70%),
    var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  overflow: hidden;
}
.cta-banner::before, .cta-banner::after {
  content: '';
  position: absolute;
  width: 300px; height: 300px;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.25;
  pointer-events: none;
}
.cta-banner::before {
  top: -100px; left: -100px;
  background: var(--brand-blue);
}
.cta-banner::after {
  bottom: -100px; right: -100px;
  background: var(--accent-orange);
}
.cta-banner-inner {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin: 0 auto;
  padding: 0 var(--container-pad);
}
.cta-banner h2 { margin-bottom: 16px; }
.cta-banner p { margin-bottom: 32px; font-size: 1.0625rem; }
.cta-banner-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

/* --- Footer --- */
.footer {
  background: var(--bg-footer);
  border-top: 1px solid var(--border-subtle);
  padding: 64px 0 24px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr 1.4fr;
  gap: 40px;
  margin-bottom: 48px;
}
.footer-brand .nav-brand { margin-bottom: 16px; }
.footer-brand p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 280px;
}
.footer-col h4 {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col a {
  font-size: 0.875rem;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}
.footer-col a:hover { color: var(--brand-blue); }
.footer-col .coming {
  font-size: 0.6875rem;
  color: var(--text-muted);
  background: var(--bg-elevated);
  padding: 2px 6px;
  border-radius: var(--radius-full);
  margin-left: 6px;
}
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 24px;
  border-top: 1px solid var(--border-subtle);
  flex-wrap: wrap;
  gap: 16px;
}
.footer-bottom p {
  font-size: 0.8125rem;
  color: var(--text-muted);
}
.footer-legal {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}
.footer-legal a {
  font-size: 0.8125rem;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}
.footer-legal a:hover { color: var(--text-secondary); }
.footer-beian a {
  color: var(--text-muted) !important;
  text-decoration: none !important;
}
.footer-beian a:hover { color: var(--text-secondary) !important; }

/* === 7. Page-specific: subpages ============================== */

/* --- Page Header (subpages) --- */
.page-header {
  position: relative;
  padding: 140px 0 80px;
  text-align: center;
  background: var(--gradient-hero);
  border-bottom: 1px solid var(--border-subtle);
  overflow: hidden;
}
.page-header-inner { max-width: 820px; margin: 0 auto; padding: 0 var(--container-pad); position: relative; z-index: 1; }
.page-header h1 { margin-bottom: 20px; }
.page-header .lead { color: var(--text-secondary); }

/* --- Feature grid (GEO Master etc.) --- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

/* --- Two column layout --- */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.two-col-text h2 { margin-bottom: 20px; }
.two-col-text p { margin-bottom: 16px; }
.two-col-visual {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 32px;
  min-height: 360px;
  position: relative;
  overflow: hidden;
}

/* --- Vertical timeline (KAIF page) --- */
.v-timeline {
  position: relative;
  padding-left: 40px;
}
.v-timeline::before {
  content: '';
  position: absolute;
  left: 14px; top: 8px; bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--brand-blue), var(--accent-orange));
}
.v-timeline-item {
  position: relative;
  padding-bottom: 48px;
}
.v-timeline-item:last-child { padding-bottom: 0; }
.v-timeline-item::before {
  content: '';
  position: absolute;
  left: -33px; top: 4px;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--brand-blue);
  border: 3px solid var(--bg-void);
  box-shadow: 0 0 0 2px var(--brand-blue);
}
.v-timeline-item:last-child::before { background: var(--accent-orange); box-shadow: 0 0 0 2px var(--accent-orange); }
.v-timeline-step {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--brand-blue);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 6px;
}
.v-timeline-title { font-size: 1.5rem; margin-bottom: 10px; }
.v-timeline-text { color: var(--text-secondary); }

/* --- Workflow diagram (AI Board) --- */
.workflow-diagram {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 48px;
  position: relative;
}
.workflow-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}
.workflow-node {
  padding: 12px 20px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
}
.workflow-arrow {
  color: var(--brand-blue);
  font-size: 1.25rem;
}

/* --- Contact layout --- */
.contact-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 48px;
  align-items: start;
}
.contact-info-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 16px;
}
.contact-info-item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 14px 0;
  border-bottom: 1px solid var(--border-subtle);
}
.contact-info-item:last-child { border-bottom: none; }
.contact-info-item .icon {
  width: 36px; height: 36px;
  border-radius: var(--radius);
  background: rgba(59, 130, 246, 0.10);
  color: var(--brand-blue);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.contact-info-item .icon svg { width: 18px; height: 18px; }
.contact-info-item .label { font-size: 0.8125rem; color: var(--text-muted); margin-bottom: 2px; }
.contact-info-item .value { font-size: 0.9375rem; color: var(--text-primary); }

/* --- Demo dashboard (AI Checkup) --- */
.demo-dashboard {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 32px;
  position: relative;
  overflow: hidden;
}
.demo-row { display: flex; gap: 16px; margin-bottom: 16px; }
.demo-card {
  flex: 1;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  padding: 16px;
}
.demo-card .label { font-size: 0.75rem; color: var(--text-muted); margin-bottom: 6px; }
.demo-card .num {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}
.demo-card .num .unit { font-size: 0.875rem; color: var(--text-muted); font-weight: 400; margin-left: 4px; }
.demo-bar {
  height: 6px;
  background: var(--bg-void);
  border-radius: 3px;
  margin-top: 8px;
  overflow: hidden;
}
.demo-bar .fill {
  height: 100%;
  background: var(--brand-blue);
  border-radius: 3px;
}

/* === 8. Responsive ============================================= */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-brand { grid-column: 1 / -1; margin-bottom: 16px; }
  .product-matrix { grid-template-columns: repeat(2, 1fr); }
  .kaif-timeline { grid-template-columns: repeat(4, 1fr); gap: 24px; }
  .kaif-timeline::before { display: none; }
  .agent-grid { grid-template-columns: repeat(4, 1fr); }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 24px; }
}

@media (max-width: 768px) {
  :root { --container-pad: 16px; }

  .nav-links, .nav-cta .lang-switch { display: none; }
  .nav-toggle { display: flex; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px; left: 0; right: 0;
    background: var(--bg-void);
    border-bottom: 1px solid var(--border-subtle);
    padding: 16px;
    align-items: stretch;
    gap: 4px;
  }
  .nav-links.open .nav-link { padding: 12px 14px; }
  .nav-links.open .dropdown {
    position: static;
    opacity: 1; visibility: visible; transform: none;
    box-shadow: none;
    background: var(--bg-elevated);
    margin: 4px 0 4px 14px;
  }

  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .product-matrix { grid-template-columns: 1fr; }
  .influence-grid { grid-template-columns: 1fr; }
  .kaif-timeline { grid-template-columns: repeat(2, 1fr); }
  .agent-grid { grid-template-columns: repeat(2, 1fr); }
  .two-col { grid-template-columns: 1fr; gap: 32px; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }

  .hero { padding: 100px 0 60px; min-height: auto; }
  .hero-cta { flex-direction: column; }
  .hero-cta .btn { width: 100%; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 20px; }

  .section { padding: 56px 0; }
  .card { padding: 20px; }
  .workflow-diagram { padding: 24px; }
}

@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
  .kaif-timeline { grid-template-columns: 1fr; }
  .agent-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: 1fr; }
  .demo-row { flex-direction: column; }
}

/* === 9. Utility =============================================== */
.hidden { display: none !important; }
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .hero-canvas { display: none; }
}

/* === Form Message (submit result) === */
.form-message { margin-top:16px; padding:14px 18px; border-radius:10px; font-size:0.9rem; display:none; }
.form-message.success { display:block; background:rgba(34,197,94,0.12); border:1px solid rgba(34,197,94,0.4); color:#4ade80; }
.form-message.error { display:block; background:rgba(239,68,68,0.12); border:1px solid rgba(239,68,68,0.4); color:#f87171; }