/* === BIẾN TOÀN CỤC === */
:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --primary-light: #e8f0fe;
  --accent: #34a853;
  --accent-dark: #2d9249;
  --bg-dark: #0f1923;
  --bg-card: #1a2736;
  --bg-card-hover: #213345;
  --text-primary: #e8eaed;
  --text-secondary: #9aa0a6;
  --text-dark: #202124;
  --gradient-primary: linear-gradient(135deg, #1a73e8 0%, #6c5ce7 50%, #a855f7 100%);
  --gradient-accent: linear-gradient(135deg, #34a853 0%, #1a73e8 100%);
  --gradient-hero: linear-gradient(160deg, #0f1923 0%, #1a2f45 40%, #0f1923 100%);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.4);
  --shadow-glow: 0 0 30px rgba(26,115,232,0.3);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  text-decoration: none;
  color: inherit;
}

ul { list-style: none; }

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

/* === TYPOGRAPHY === */
h1, h2, h3, h4, h5 {
  font-weight: 700;
  line-height: 1.2;
}

h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.8rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.5rem); }

.gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* === BỐ CỤC CHUNG === */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 100px 0;
  position: relative;
}

/* === NAVIGATION === */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: var(--transition);
  background: transparent;
}

.navbar.scrolled {
  background: rgba(15, 25, 35, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.05);
  padding: 10px 0;
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.nav-logo .logo-icon {
  width: 36px;
  height: 36px;
  background: var(--gradient-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
  position: relative;
}

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

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: var(--transition);
}

.nav-links a:hover::after {
  width: 100%;
}

.nav-cta {
  padding: 10px 24px !important;
  background: var(--gradient-primary) !important;
  border-radius: var(--radius-xl) !important;
  color: white !important;
  font-weight: 600 !important;
  transition: var(--transition);
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.nav-cta::after {
  display: none !important;
}

/* Hamburger Menu */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}

.nav-hamburger span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: var(--transition);
  border-radius: 2px;
}

/* === NÚT BẤM === */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: var(--radius-xl);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  font-family: inherit;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 4px 15px rgba(26, 115, 232, 0.4);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(26, 115, 232, 0.5);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1.5px solid rgba(255,255,255,0.15);
}

.btn-secondary:hover {
  border-color: var(--primary);
  background: rgba(26, 115, 232, 0.1);
  transform: translateY(-3px);
}

.btn-accent {
  background: var(--gradient-accent);
  color: white;
  box-shadow: 0 4px 15px rgba(52, 168, 83, 0.4);
}

.btn-accent:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(52, 168, 83, 0.5);
}

/* === HERO SECTION === */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
  padding-top: 80px;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(26,115,232,0.12) 0%, transparent 70%);
  border-radius: 50%;
  animation: pulse-glow 6s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(168,85,247,0.08) 0%, transparent 70%);
  border-radius: 50%;
  animation: pulse-glow 8s ease-in-out infinite reverse;
}

@keyframes pulse-glow {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(1.1); opacity: 1; }
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 2;
}

.hero-content {
  animation: fadeInUp 0.8s ease-out;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(26, 115, 232, 0.15);
  border: 1px solid rgba(26, 115, 232, 0.3);
  border-radius: var(--radius-xl);
  font-size: 0.8rem;
  font-weight: 600;
  color: #7abaff;
  margin-bottom: 24px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.hero-badge::before {
  content: '';
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
  animation: blink 2s infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

.hero h1 {
  margin-bottom: 20px;
  letter-spacing: -1px;
}

.hero p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 36px;
  max-width: 500px;
  line-height: 1.8;
}

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

.hero-visual {
  position: relative;
  animation: fadeInRight 1s ease-out 0.3s both;
}

.hero-dashboard {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255,255,255,0.08);
  padding: 24px;
  box-shadow: var(--shadow-lg);
  position: relative;
}

.hero-dashboard::before {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, rgba(26,115,232,0.2), transparent, rgba(168,85,247,0.2));
  z-index: -1;
}

.dashboard-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.dashboard-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.dashboard-dot.red { background: #ea4335; }
.dashboard-dot.yellow { background: #fbbc04; }
.dashboard-dot.green { background: #34a853; }

.dashboard-title {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-left: 8px;
}

.dashboard-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

.stat-card {
  background: rgba(255,255,255,0.03);
  border-radius: var(--radius-sm);
  padding: 16px;
  border: 1px solid rgba(255,255,255,0.04);
}

.stat-card .stat-label {
  font-size: 0.7rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}

.stat-card .stat-value {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
}

.stat-card .stat-change {
  font-size: 0.7rem;
  color: var(--accent);
  margin-top: 4px;
}

.stat-card .stat-change.negative {
  color: #ea4335;
}

.dashboard-chart {
  height: 120px;
  background: linear-gradient(180deg, rgba(26,115,232,0.1) 0%, transparent 100%);
  border-radius: var(--radius-sm);
  position: relative;
  overflow: hidden;
}

.chart-line {
  position: absolute;
  bottom: 20px;
  left: 0;
  right: 0;
  height: 2px;
}

.chart-line svg {
  width: 100%;
  height: 80px;
  position: absolute;
  bottom: 0;
}

/* Floating Cards */
.floating-card {
  position: absolute;
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  box-shadow: var(--shadow-md);
  animation: float 4s ease-in-out infinite;
  z-index: 3;
}

.floating-card.card-1 {
  top: -20px;
  right: -30px;
  animation-delay: 0s;
}

.floating-card.card-2 {
  bottom: -15px;
  left: -20px;
  animation-delay: 2s;
}

.floating-card .fc-icon {
  font-size: 1.2rem;
  margin-bottom: 4px;
}

.floating-card .fc-label {
  font-size: 0.65rem;
  color: var(--text-secondary);
}

.floating-card .fc-value {
  font-size: 0.9rem;
  font-weight: 700;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInRight {
  from { opacity: 0; transform: translateX(30px); }
  to { opacity: 1; transform: translateX(0); }
}

/* === FEATURES SECTION === */
.features {
  background: var(--bg-dark);
}

.section-header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 64px;
}

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(26, 115, 232, 0.1);
  border: 1px solid rgba(26, 115, 232, 0.2);
  border-radius: var(--radius-xl);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 16px;
}

.section-header p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-top: 12px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
  transform: scaleX(0);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-8px);
  border-color: rgba(26,115,232,0.2);
  box-shadow: var(--shadow-md);
}

.feature-card:hover::before {
  transform: scaleX(1);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
}

.feature-icon.blue { background: rgba(26,115,232,0.15); }
.feature-icon.green { background: rgba(52,168,83,0.15); }
.feature-icon.purple { background: rgba(168,85,247,0.15); }
.feature-icon.orange { background: rgba(251,188,4,0.15); }
.feature-icon.red { background: rgba(234,67,53,0.15); }
.feature-icon.teal { background: rgba(0,188,212,0.15); }

.feature-card h3 {
  margin-bottom: 10px;
  font-size: 1.15rem;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

/* === STATS SECTION === */
.stats-section {
  background: linear-gradient(180deg, var(--bg-dark) 0%, #0d1820 100%);
  padding: 80px 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.stats-item {
  text-align: center;
  padding: 32px 20px;
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg);
  transition: var(--transition);
}

.stats-item:hover {
  transform: translateY(-4px);
  border-color: rgba(26,115,232,0.2);
}

.stats-number {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.stats-label {
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
}

/* === WORKFLOW SECTION === */
.workflow {
  background: var(--bg-dark);
}

.workflow-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  position: relative;
}

.workflow-steps::before {
  content: '';
  position: absolute;
  top: 36px;
  left: 14%;
  right: 14%;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  opacity: 0.3;
}

.workflow-step {
  text-align: center;
  position: relative;
}

.step-number {
  width: 72px;
  height: 72px;
  margin: 0 auto 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 800;
  background: var(--bg-card);
  border: 2px solid rgba(26,115,232,0.3);
  color: var(--primary);
  position: relative;
  z-index: 2;
  transition: var(--transition);
}

.workflow-step:hover .step-number {
  background: var(--gradient-primary);
  color: white;
  border-color: transparent;
  box-shadow: var(--shadow-glow);
}

.workflow-step h3 {
  margin-bottom: 8px;
  font-size: 1.05rem;
}

.workflow-step p {
  color: var(--text-secondary);
  font-size: 0.85rem;
}

/* === CTA SECTION === */
.cta-section {
  background: var(--bg-dark);
  position: relative;
  overflow: hidden;
}

.cta-box {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-xl);
  padding: 80px 60px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-box::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center, rgba(26,115,232,0.1) 0%, transparent 70%);
}

.cta-box h2 {
  margin-bottom: 16px;
  position: relative;
}

.cta-box p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: 36px;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
  position: relative;
}

.cta-buttons {
  display: flex;
  justify-content: center;
  gap: 16px;
  position: relative;
}

/* === FOOTER === */
.footer {
  background: #0a1018;
  padding: 64px 0 32px;
  border-top: 1px solid rgba(255,255,255,0.04);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin-top: 12px;
  max-width: 280px;
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 16px;
  color: var(--text-secondary);
}

.footer-col a {
  display: block;
  color: var(--text-secondary);
  font-size: 0.85rem;
  padding: 4px 0;
  transition: var(--transition);
}

.footer-col a:hover {
  color: var(--primary);
  transform: translateX(4px);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid rgba(255,255,255,0.06);
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-secondary);
  font-size: 0.8rem;
}

.footer-bottom-links {
  display: flex;
  gap: 24px;
}

.footer-bottom-links a {
  color: var(--text-secondary);
  transition: var(--transition);
}

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

/* === TRANG PHỤ: ABOUT, PRIVACY, CONTACT === */
.page-hero {
  padding: 140px 0 80px;
  background: var(--gradient-hero);
  text-align: center;
  position: relative;
}

.page-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(26,115,232,0.1) 0%, transparent 70%);
  border-radius: 50%;
}

.page-hero h1 {
  position: relative;
  margin-bottom: 12px;
}

.page-hero p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  position: relative;
}

.page-content {
  padding: 80px 0;
}

.page-content .container {
  max-width: 800px;
}

.content-section {
  margin-bottom: 48px;
}

.content-section h2 {
  font-size: 1.4rem;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.content-section p,
.content-section li {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.8;
  margin-bottom: 12px;
}

.content-section ul {
  padding-left: 20px;
  list-style: disc;
}

.content-section ul li {
  margin-bottom: 8px;
}

/* Contact Form */
.contact-form {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-lg);
  padding: 40px;
}

.form-group {
  margin-bottom: 24px;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: inherit;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26,115,232,0.15);
}

.form-group textarea {
  min-height: 140px;
  resize: vertical;
}

/* === TEAM SECTION === */
.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 48px;
}

.team-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  transition: var(--transition);
}

.team-card:hover {
  transform: translateY(-4px);
  border-color: rgba(26,115,232,0.2);
}

.team-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  margin: 0 auto 16px;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
}

.team-card h3 {
  margin-bottom: 4px;
}

.team-card .role {
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 500;
}

/* === RESPONSIVE === */
@media (max-width: 1024px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero p { margin: 0 auto 36px; }
  .hero-buttons { justify-content: center; }
  .hero-visual { max-width: 500px; margin: 0 auto; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .workflow-steps { grid-template-columns: repeat(2, 1fr); }
  .workflow-steps::before { display: none; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(15,25,35,0.98);
    backdrop-filter: blur(20px);
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }
  .nav-hamburger { display: flex; }
  .features-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .workflow-steps { grid-template-columns: 1fr; }
  .cta-box { padding: 48px 24px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 12px; }
  .team-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .hero-buttons { flex-direction: column; }
  .btn { width: 100%; justify-content: center; }
  .stats-grid { grid-template-columns: 1fr; }
  .cta-buttons { flex-direction: column; align-items: center; }
}