/* ==========================================================================
   ROBOT ASSISTANT - MODERN LIGHT AURORA DESIGN SYSTEM
   Phong cách: Chữ mỏng thanh lịch (Thin Typography), Nền sáng loang (Aurora Mesh Gradient),
   Dễ nhìn, Bắt mắt & Tinh tế.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@200;300;400;500;600&family=Plus+Jakarta+Sans:wght@300;400;500;600&family=JetBrains+Mono:wght@300;400;500&display=swap');

:root {
  /* Font Families */
  --font-display: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Theme: Pastel Sunrise (Default) */
  --bg-base: #f8fafc;
  --bg-surface: rgba(255, 255, 255, 0.72);
  --bg-surface-elevated: rgba(255, 255, 255, 0.88);
  --bg-surface-hover: rgba(255, 255, 255, 0.95);
  
  /* Aurora Mesh Gradient Colors */
  --aurora-1: rgba(168, 85, 247, 0.28);  /* Soft Purple */
  --aurora-2: rgba(56, 189, 248, 0.32);  /* Sky Cyan */
  --aurora-3: rgba(244, 114, 182, 0.25); /* Rose Pink */
  --aurora-4: rgba(52, 211, 153, 0.24);  /* Mint Green */
  --aurora-5: rgba(251, 146, 60, 0.20);  /* Soft Peach */
  
  /* Text Colors - Tối ưu cho chữ mỏng (Thin font) mà vẫn sắc nét, tương phản cao */
  --text-primary: #0f172a;       /* Slate 900 - Rất rõ ràng, không mỏi mắt */
  --text-secondary: #334155;     /* Slate 700 */
  --text-muted: #64748b;         /* Slate 500 */
  --text-light: #94a3b8;         /* Slate 400 */
  
  /* Brand Accents */
  --accent-primary: #6366f1;
  --accent-secondary: #06b6d4;
  --accent-gradient: linear-gradient(135deg, #4f46e5 0%, #06b6d4 50%, #ec4899 100%);
  --accent-gradient-text: linear-gradient(135deg, #312e81 0%, #4338ca 30%, #0369a1 70%, #9333ea 100%);
  
  /* Borders & Shadows */
  --border-subtle: rgba(255, 255, 255, 0.8);
  --border-glass: rgba(226, 232, 240, 0.7);
  --border-accent: rgba(99, 102, 241, 0.25);
  --shadow-sm: 0 4px 12px rgba(15, 23, 42, 0.03);
  --shadow-md: 0 10px 30px -10px rgba(99, 102, 241, 0.08), 0 4px 16px rgba(15, 23, 42, 0.03);
  --shadow-lg: 0 20px 45px -12px rgba(79, 70, 229, 0.12), 0 8px 24px rgba(15, 23, 42, 0.04);
  --shadow-glow: 0 0 35px rgba(56, 189, 248, 0.25);

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-full: 9999px;

  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Theme 2: Cyber Blue Aurora */
[data-theme="cyan-aurora"] {
  --bg-base: #f0fdfa;
  --aurora-1: rgba(6, 182, 212, 0.32);
  --aurora-2: rgba(59, 130, 246, 0.35);
  --aurora-3: rgba(16, 185, 129, 0.28);
  --aurora-4: rgba(147, 51, 234, 0.22);
  --aurora-5: rgba(14, 165, 233, 0.25);
  --accent-primary: #0284c7;
  --accent-secondary: #0d9488;
  --shadow-glow: 0 0 35px rgba(6, 182, 212, 0.3);
}

/* Theme 3: Sunset Peach Glow */
[data-theme="sunset-glow"] {
  --bg-base: #fff7ed;
  --aurora-1: rgba(244, 63, 94, 0.28);
  --aurora-2: rgba(249, 115, 22, 0.28);
  --aurora-3: rgba(168, 85, 247, 0.25);
  --aurora-4: rgba(234, 179, 8, 0.22);
  --aurora-5: rgba(236, 72, 153, 0.25);
  --accent-primary: #ea580c;
  --accent-secondary: #db2777;
  --shadow-glow: 0 0 35px rgba(249, 115, 22, 0.3);
}

/* ==========================================================================
   BASE & RESET
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  font-weight: 300; /* Chữ mỏng tự nhiên, thanh thoát */
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text-secondary);
  background-color: var(--bg-base);
  position: relative;
  overflow-x: hidden;
  min-height: 100vh;
}

/* ==========================================================================
   NỀN MÀU SÁNG LOANG (AURORA MESH BACKGROUND ANIMATION)
   ========================================================================== */
.aurora-background {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
  background-color: var(--bg-base);
}

.aurora-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.85;
  will-change: transform;
  animation-iteration-count: infinite;
  animation-timing-function: ease-in-out;
}

.blob-1 {
  width: 65vw;
  height: 65vw;
  max-width: 800px;
  max-height: 800px;
  background: var(--aurora-1);
  top: -15%;
  left: -10%;
  animation: floatOrb1 22s infinite alternate;
}

.blob-2 {
  width: 55vw;
  height: 55vw;
  max-width: 700px;
  max-height: 700px;
  background: var(--aurora-2);
  top: 10%;
  right: -15%;
  animation: floatOrb2 26s infinite alternate;
}

.blob-3 {
  width: 50vw;
  height: 50vw;
  max-width: 650px;
  max-height: 650px;
  background: var(--aurora-3);
  bottom: 15%;
  left: 10%;
  animation: floatOrb3 20s infinite alternate;
}

.blob-4 {
  width: 60vw;
  height: 60vw;
  max-width: 750px;
  max-height: 750px;
  background: var(--aurora-4);
  bottom: -20%;
  right: -10%;
  animation: floatOrb4 24s infinite alternate;
}

.blob-5 {
  width: 45vw;
  height: 45vw;
  max-width: 550px;
  max-height: 550px;
  background: var(--aurora-5);
  top: 40%;
  left: 35%;
  animation: floatOrb5 18s infinite alternate;
}

@keyframes floatOrb1 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(120px, 80px) scale(1.12); }
  100% { transform: translate(-60px, 140px) scale(0.92); }
}

@keyframes floatOrb2 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-140px, 100px) scale(1.08); }
  100% { transform: translate(-80px, -60px) scale(0.95); }
}

@keyframes floatOrb3 {
  0% { transform: translate(0, 0) scale(0.95); }
  50% { transform: translate(100px, -120px) scale(1.15); }
  100% { transform: translate(40px, 80px) scale(1); }
}

@keyframes floatOrb4 {
  0% { transform: translate(0, 0) scale(1.05); }
  50% { transform: translate(-100px, -90px) scale(0.92); }
  100% { transform: translate(80px, -120px) scale(1.1); }
}

@keyframes floatOrb5 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-80px, 60px) scale(1.15); }
  100% { transform: translate(100px, -70px) scale(0.9); }
}

/* Subtle grid overlay tạo chiều sâu công nghệ */
.aurora-grid-overlay {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(rgba(148, 163, 184, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 184, 0.05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(circle at 50% 50%, black 60%, transparent 95%);
  pointer-events: none;
}

/* ==========================================================================
   TYPOGRAPHY - CHỮ MỎNG THANH LỊCH (THIN & ULTRA-SLEEK)
   ========================================================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 300; /* Headings mỏng, chuẩn phong cách cao cấp */
  color: var(--text-primary);
  line-height: 1.25;
  letter-spacing: -0.025em;
}

h1 {
  font-size: clamp(2.5rem, 5.5vw, 4.25rem);
  font-weight: 250; /* Cực mỏng, tinh tế */
}

h2 {
  font-size: clamp(2rem, 3.8vw, 3rem);
  font-weight: 300;
}

h3 {
  font-size: clamp(1.35rem, 2.2vw, 1.75rem);
  font-weight: 350;
}

h4 {
  font-size: 1.2rem;
  font-weight: 400;
}

p {
  font-weight: 300;
  letter-spacing: -0.01em;
}

.text-gradient {
  background: var(--accent-gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
  font-weight: 350;
}

.text-thin {
  font-weight: 200;
}

.text-light {
  font-weight: 300;
}

.text-regular {
  font-weight: 400;
}

.text-medium {
  font-weight: 500;
}

/* ==========================================================================
   LAYOUT CONTAINERS & GLASSMORPHISM
   ========================================================================== */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.glass-panel {
  background: var(--bg-surface);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-smooth);
}

.glass-panel:hover {
  background: var(--bg-surface-hover);
  border-color: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-lg);
}

.glass-card {
  background: var(--bg-surface);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.85);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth), border-color var(--transition-smooth);
  position: relative;
  overflow: hidden;
}

.glass-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, rgba(99, 102, 241, 0.3), transparent);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.glass-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-accent);
}

.glass-card:hover::before {
  opacity: 1;
}

/* ==========================================================================
   HEADER & NAVBAR
   ========================================================================== */
.navbar-wrapper {
  position: fixed;
  top: 1rem;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 0 1.5rem;
  transition: all var(--transition-smooth);
}

.navbar {
  max-width: 1240px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.5rem;
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: var(--radius-full);
  box-shadow: 0 8px 30px rgba(15, 23, 42, 0.05);
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
}

.brand-avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, #e0e7ff 0%, #fae8ff 100%);
  border: 1px solid rgba(99, 102, 241, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  box-shadow: 0 4px 10px rgba(99, 102, 241, 0.15);
}

.brand-avatar svg {
  width: 20px;
  height: 20px;
  color: var(--accent-primary);
}

.status-dot {
  position: absolute;
  bottom: 0px;
  right: 0px;
  width: 10px;
  height: 10px;
  background-color: #10b981;
  border: 2px solid #ffffff;
  border-radius: 50%;
  animation: pulseGreen 2.5s infinite;
}

@keyframes pulseGreen {
  0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.6); }
  70% { box-shadow: 0 0 0 6px rgba(16, 185, 129, 0); }
  100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.brand-name span {
  font-weight: 250;
  color: var(--text-muted);
  margin-left: 0.25rem;
  font-size: 0.95rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.925rem;
  font-weight: 300;
  transition: color var(--transition-fast);
  position: relative;
  padding: 0.35rem 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
  font-weight: 400;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--accent-primary);
  transition: width var(--transition-fast);
  border-radius: 2px;
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Theme picker pill */
.theme-switcher {
  display: flex;
  align-items: center;
  background: rgba(241, 245, 249, 0.8);
  border: 1px solid rgba(226, 232, 240, 0.8);
  border-radius: var(--radius-full);
  padding: 3px;
  gap: 3px;
}

.theme-btn {
  background: transparent;
  border: none;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast), background var(--transition-fast);
}

.theme-btn span {
  display: block;
  width: 14px;
  height: 14px;
  border-radius: 50%;
}

.theme-btn[data-theme="pastel"] span {
  background: linear-gradient(135deg, #c4b5fd, #fbcfe8);
}

.theme-btn[data-theme="cyan-aurora"] span {
  background: linear-gradient(135deg, #38bdf8, #34d399);
}

.theme-btn[data-theme="sunset-glow"] span {
  background: linear-gradient(135deg, #fb923c, #f472b6);
}

.theme-btn.active {
  background: #ffffff;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
  transform: scale(1.1);
}

/* ==========================================================================
   BUTTONS & BADGES
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.6rem;
  border-radius: var(--radius-full);
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 400;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-smooth);
  border: none;
  outline: none;
  white-space: nowrap;
}

.btn-primary {
  background: #0f172a;
  color: #ffffff;
  box-shadow: 0 6px 20px -4px rgba(15, 23, 42, 0.25);
}

.btn-primary:hover {
  background: #1e293b;
  transform: translateY(-2px);
  box-shadow: 0 10px 25px -4px rgba(15, 23, 42, 0.35);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.85);
  color: var(--text-primary);
  border: 1px solid rgba(203, 213, 225, 0.8);
  backdrop-filter: blur(12px);
}

.btn-secondary:hover {
  background: #ffffff;
  border-color: rgba(148, 163, 184, 0.8);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn-gradient {
  background: linear-gradient(135deg, #4f46e5 0%, #06b6d4 100%);
  color: #ffffff;
  box-shadow: 0 8px 24px -6px rgba(79, 70, 229, 0.4);
}

.btn-gradient:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -6px rgba(79, 70, 229, 0.55);
  filter: brightness(1.05);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.825rem;
  font-weight: 400;
  letter-spacing: 0.02em;
}

.badge-aurora {
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(226, 232, 240, 0.9);
  color: var(--text-primary);
  backdrop-filter: blur(12px);
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.06);
}

.badge-aurora .sparkle {
  color: #f59e0b;
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */
.hero-section {
  padding-top: calc(5.5rem + 3vw);
  padding-bottom: 5rem;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.95fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.hero-title {
  margin-top: 0.5rem;
  line-height: 1.15;
}

.hero-desc {
  font-size: 1.15rem;
  line-height: 1.8;
  color: var(--text-secondary);
  font-weight: 300;
  max-width: 580px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 0.5rem;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(203, 213, 225, 0.4);
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.stat-number {
  font-family: var(--font-display);
  font-size: 1.85rem;
  font-weight: 250;
  color: var(--text-primary);
  letter-spacing: -0.03em;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 300;
}

/* Hero Showcase Visual Card */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.hero-card {
  position: relative;
  width: 100%;
  max-width: 520px;
  background: rgba(255, 255, 255, 0.65);
  backdrop-filter: blur(28px);
  -webkit-backdrop-filter: blur(28px);
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: var(--radius-xl);
  padding: 1.25rem;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transition: transform var(--transition-smooth);
}

.hero-card:hover {
  transform: translateY(-4px);
}

.robot-image-wrap {
  position: relative;
  width: 100%;
  border-radius: calc(var(--radius-xl) - 8px);
  overflow: hidden;
  background: #ffffff;
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.04);
}

.robot-image-wrap img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.hero-card:hover .robot-image-wrap img {
  transform: scale(1.02);
}

/* Floating interactive HUD pill over robot image */
.hud-pill {
  position: absolute;
  bottom: 1rem;
  left: 1rem;
  right: 1rem;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.95);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.1);
}

.hud-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.hud-wave-bars {
  display: flex;
  align-items: center;
  gap: 3px;
  height: 20px;
}

.wave-bar {
  width: 3px;
  background: var(--accent-primary);
  border-radius: 2px;
  animation: waveBar 1.2s ease-in-out infinite;
}

.wave-bar:nth-child(1) { height: 8px; animation-delay: 0.1s; }
.wave-bar:nth-child(2) { height: 16px; animation-delay: 0.3s; }
.wave-bar:nth-child(3) { height: 22px; animation-delay: 0.2s; }
.wave-bar:nth-child(4) { height: 14px; animation-delay: 0.4s; }
.wave-bar:nth-child(5) { height: 9px; animation-delay: 0.15s; }

@keyframes waveBar {
  0%, 100% { transform: scaleY(0.4); }
  50% { transform: scaleY(1); }
}

.hud-text {
  display: flex;
  flex-direction: column;
}

.hud-title {
  font-size: 0.825rem;
  font-weight: 500;
  color: var(--text-primary);
}

.hud-status {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 300;
}

.hud-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  background: rgba(99, 102, 241, 0.1);
  color: var(--accent-primary);
  padding: 0.25rem 0.55rem;
  border-radius: var(--radius-full);
}

/* ==========================================================================
   INTERACTIVE SIMULATOR & PLAYGROUND SECTION
   ========================================================================== */
.section {
  padding: 5.5rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 3.5rem auto;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  align-items: center;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  font-weight: 300;
  line-height: 1.7;
}

.simulator-wrapper {
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid rgba(255, 255, 255, 0.95);
  border-radius: var(--radius-xl);
  padding: 2.25rem;
  box-shadow: var(--shadow-lg);
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 2.5rem;
  align-items: stretch;
}

/* Left side of simulator: Virtual Robot Screen & Expression Controls */
.sim-robot-pane {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  align-items: center;
}

.virtual-screen-box {
  width: 100%;
  max-width: 380px;
  background: #090d16;
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  border: 2px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 15px 35px -5px rgba(15, 23, 42, 0.3), inset 0 0 20px rgba(56, 189, 248, 0.08);
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.screen-glare {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 50%;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.05), transparent);
  pointer-events: none;
}

.screen-header-bar {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: #64748b;
}

.virtual-face-canvas {
  width: 240px;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.face-eyes {
  display: flex;
  gap: 48px;
  align-items: center;
}

.eye {
  width: 42px;
  height: 48px;
  background: #38bdf8;
  border-radius: 24px;
  box-shadow: 0 0 18px #38bdf8, 0 0 35px rgba(56, 189, 248, 0.5);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Eye state variations */
.virtual-screen-box[data-emotion="happy"] .eye {
  height: 24px;
  border-radius: 24px 24px 6px 6px;
  transform: translateY(-4px);
}

.virtual-screen-box[data-emotion="listening"] .eye {
  height: 52px;
  background: #a855f7;
  box-shadow: 0 0 20px #a855f7;
  animation: pulseEye 1s infinite alternate;
}

.virtual-screen-box[data-emotion="thinking"] .eye {
  width: 36px;
  height: 36px;
  background: #f59e0b;
  box-shadow: 0 0 20px #f59e0b;
  animation: spinEye 2.5s infinite linear;
}

.virtual-screen-box[data-emotion="talking"] .eye {
  background: #10b981;
  box-shadow: 0 0 20px #10b981;
}

@keyframes pulseEye {
  from { transform: scale(0.95); }
  to { transform: scale(1.08); }
}

@keyframes spinEye {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.screen-subtext {
  margin-top: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: #94a3b8;
  text-align: center;
  min-height: 22px;
}

/* Face Emotion Switcher buttons */
.emotion-picker {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  width: 100%;
}

.emotion-btn {
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(226, 232, 240, 0.9);
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 300;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.emotion-btn:hover, .emotion-btn.active {
  background: var(--text-primary);
  color: #ffffff;
  border-color: var(--text-primary);
}

/* Right side of simulator: Interactive Prompts & Live Pipeline */
.sim-pipeline-pane {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.sim-pane-title {
  font-size: 1.2rem;
  font-weight: 400;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.prompt-chips {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.prompt-chip {
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(226, 232, 240, 0.9);
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem;
  font-size: 0.88rem;
  font-weight: 300;
  color: var(--text-secondary);
  text-align: left;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  transition: all var(--transition-fast);
}

.prompt-chip:hover {
  background: #ffffff;
  border-color: var(--accent-primary);
  transform: translateX(4px);
  box-shadow: var(--shadow-sm);
  color: var(--text-primary);
}

.prompt-chip.active {
  background: rgba(99, 102, 241, 0.08);
  border-color: var(--accent-primary);
  color: var(--text-primary);
  font-weight: 400;
}

.chip-arrow {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Pipeline Flow Visualizer Box */
.pipeline-terminal {
  background: #0f172a;
  border-radius: var(--radius-md);
  padding: 1.25rem;
  color: #e2e8f0;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  min-height: 240px;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.4);
}

.terminal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding-bottom: 0.5rem;
  color: #94a3b8;
  font-size: 0.75rem;
}

.terminal-dots {
  display: flex;
  gap: 5px;
}

.t-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #475569;
}

.terminal-logs {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  overflow-y: auto;
  max-height: 200px;
}

.log-entry {
  display: flex;
  gap: 0.5rem;
  line-height: 1.5;
  animation: fadeInLog 0.3s ease-out;
}

@keyframes fadeInLog {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

.log-tag {
  color: #38bdf8;
  flex-shrink: 0;
}

.log-tag.router { color: #a855f7; }
.log-tag.mcp { color: #f59e0b; }
.log-tag.tts { color: #10b981; }

.log-msg {
  color: #cbd5e1;
}

.json-block {
  background: rgba(255, 255, 255, 0.04);
  padding: 0.5rem;
  border-radius: 6px;
  color: #93c5fd;
  font-size: 0.75rem;
}

/* ==========================================================================
   FEATURES GRID (CÁC TÍNH NĂNG VƯỢT TRỘI)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-card {
  padding: 2.25rem 1.85rem;
  display: flex;
  flex-direction: column;
  gap: 1.15rem;
  position: relative;
}

.feature-icon-wrapper {
  width: 54px;
  height: 54px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.95), rgba(241, 245, 249, 0.7));
  border: 1px solid rgba(255, 255, 255, 0.95);
  box-shadow: 0 8px 18px -4px rgba(99, 102, 241, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
}

.feature-title {
  font-size: 1.35rem;
  font-weight: 350;
  color: var(--text-primary);
  line-height: 1.35;
}

.feature-desc {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text-secondary);
  font-weight: 300;
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: auto;
  padding-top: 0.5rem;
}

.feature-tag {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  background: rgba(241, 245, 249, 0.8);
  border: 1px solid rgba(226, 232, 240, 0.8);
  color: var(--text-muted);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-full);
}

/* ==========================================================================
   ARCHITECTURE SECTION (KIẾN TRÚC 4 THÀNH PHẦN)
   ========================================================================== */
.arch-container {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 2.5rem;
  align-items: center;
}

.arch-nav {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.arch-tab-btn {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(226, 232, 240, 0.8);
  border-radius: var(--radius-md);
  padding: 1.15rem 1.4rem;
  text-align: left;
  cursor: pointer;
  transition: all var(--transition-smooth);
  display: flex;
  align-items: center;
  gap: 1rem;
}

.arch-tab-btn:hover {
  background: rgba(255, 255, 255, 0.95);
  transform: translateX(4px);
  border-color: rgba(99, 102, 241, 0.3);
}

.arch-tab-btn.active {
  background: #ffffff;
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-md);
}

.arch-tab-icon {
  font-size: 1.5rem;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(241, 245, 249, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.arch-tab-btn.active .arch-tab-icon {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(6, 182, 212, 0.15));
}

.arch-tab-text h4 {
  font-size: 1.05rem;
  font-weight: 400;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}

.arch-tab-text p {
  font-size: 0.825rem;
  color: var(--text-muted);
  font-weight: 300;
}

.arch-display-panel {
  min-height: 420px;
  padding: 2.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.arch-badge-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.arch-detail-title {
  font-size: 1.85rem;
  font-weight: 300;
  margin-bottom: 1rem;
}

.arch-detail-desc {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-secondary);
  font-weight: 300;
  margin-bottom: 1.75rem;
}

.arch-feature-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 2rem;
}

.arch-list-item {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 300;
}

.arch-list-item svg {
  width: 18px;
  height: 18px;
  color: var(--accent-primary);
  flex-shrink: 0;
  margin-top: 2px;
}

.arch-footer-tags {
  display: flex;
  gap: 0.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(226, 232, 240, 0.8);
}

/* ==========================================================================
   HARDWARE & CRAFTSMANSHIP SHOWCASE
   ========================================================================== */
.hardware-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.hw-card {
  padding: 1.75rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.hw-icon {
  font-size: 1.75rem;
  margin-bottom: 0.25rem;
}

.hw-name {
  font-size: 1.15rem;
  font-weight: 400;
  color: var(--text-primary);
}

.hw-spec {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent-primary);
  background: rgba(99, 102, 241, 0.08);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  display: inline-block;
  width: fit-content;
}

.hw-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  font-weight: 300;
  line-height: 1.6;
}

/* ==========================================================================
   SAFETY & JEV DECISION ENGINE
   ========================================================================== */
.safety-box {
  padding: 3rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.safety-info {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.risk-level-cards {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.risk-card {
  padding: 1.15rem 1.4rem;
  border-radius: var(--radius-md);
  border: 1px solid;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  background: rgba(255, 255, 255, 0.8);
}

.risk-card.low {
  border-color: rgba(16, 185, 129, 0.3);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.05);
}

.risk-card.medium {
  border-color: rgba(245, 158, 11, 0.3);
  box-shadow: 0 4px 12px rgba(245, 158, 11, 0.05);
}

.risk-card.high {
  border-color: rgba(239, 68, 68, 0.3);
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.05);
}

.risk-meta {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.risk-title {
  font-weight: 400;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.risk-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 300;
}

.risk-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-full);
}

.risk-card.low .risk-badge { background: #d1fae5; color: #047857; }
.risk-card.medium .risk-badge { background: #fef3c7; color: #b45309; }
.risk-card.high .risk-badge { background: #fee2e2; color: #b91c1c; }

/* ==========================================================================
   ROADMAP SECTION
   ========================================================================== */
.roadmap-timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  position: relative;
}

.timeline-step {
  padding: 1.75rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  position: relative;
}

.timeline-step.active {
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-md);
}

.step-phase {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent-primary);
  font-weight: 500;
}

.step-title {
  font-size: 1.2rem;
  font-weight: 350;
  color: var(--text-primary);
}

.step-points {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 300;
}

.step-points li {
  position: relative;
  padding-left: 1.15rem;
}

.step-points li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--accent-primary);
}

/* ==========================================================================
   CODE & QUICK START TAB
   ========================================================================== */
.code-showcase-box {
  background: #0f172a;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.code-nav-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #1e293b;
  padding: 0.75rem 1.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.code-tabs {
  display: flex;
  gap: 0.5rem;
}

.code-tab-btn {
  background: transparent;
  border: none;
  color: #94a3b8;
  padding: 0.4rem 0.85rem;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.code-tab-btn.active, .code-tab-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
}

.code-pre {
  padding: 1.75rem;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: #e2e8f0;
  line-height: 1.7;
  overflow-x: auto;
  min-height: 180px;
}

.code-comment { color: #64748b; }
.code-cmd { color: #38bdf8; }
.code-flag { color: #a855f7; }
.code-string { color: #34d399; }

/* ==========================================================================
   FAQ SECTION (STATIC CLEAN ACCORDION GRID)
   ========================================================================== */
.faq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.faq-card {
  padding: 1.5rem 1.75rem;
  cursor: pointer;
  transition: all var(--transition-smooth);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.faq-question h4 {
  font-size: 1.05rem;
  font-weight: 350;
  color: var(--text-primary);
}

.faq-icon {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: transform var(--transition-smooth);
}

.faq-answer {
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--text-secondary);
  font-weight: 300;
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid rgba(226, 232, 240, 0.8);
  display: none;
}

.faq-card.open .faq-answer {
  display: block;
  animation: fadeInLog 0.3s ease;
}

.faq-card.open .faq-icon {
  transform: rotate(180deg);
  color: var(--accent-primary);
}

/* ==========================================================================
   CALL TO ACTION & FOOTER
   ========================================================================== */
.cta-box {
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.85), rgba(240, 249, 255, 0.85));
  backdrop-filter: blur(24px);
  border: 1px solid rgba(255, 255, 255, 0.95);
  border-radius: var(--radius-xl);
  padding: 4rem 2.5rem;
  text-align: center;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  position: relative;
  overflow: hidden;
}

.cta-box::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 60%);
  pointer-events: none;
}

.site-footer {
  padding: 4.5rem 0 2.5rem 0;
  border-top: 1px solid rgba(226, 232, 240, 0.8);
  background: rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(12px);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3.5rem;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-col-title {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.88rem;
  font-weight: 300;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--text-primary);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid rgba(226, 232, 240, 0.6);
  font-size: 0.825rem;
  color: var(--text-muted);
  font-weight: 300;
}

/* ==========================================================================
   TOAST NOTIFICATION
   ========================================================================== */
.toast-msg {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: #0f172a;
  color: #ffffff;
  padding: 0.85rem 1.4rem;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  z-index: 1000;
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.toast-msg.show {
  transform: translateY(0);
  opacity: 1;
}

/* ==========================================================================
   RESPONSIVE DESIGN (TABLET & MOBILE)
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .hero-visual {
    order: -1;
  }

  .simulator-wrapper {
    grid-template-columns: 1fr;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .arch-container {
    grid-template-columns: 1fr;
  }

  .hardware-grid, .roadmap-timeline {
    grid-template-columns: repeat(2, 1fr);
  }

  .safety-box {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .features-grid, .faq-grid {
    grid-template-columns: 1fr;
  }

  .hardware-grid, .roadmap-timeline {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }

  .arch-feature-list {
    grid-template-columns: 1fr;
  }
}