*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #0a0a0f;
  --bg-alt: #111118;
  --surface: #1a1a24;
  --surface-hover: #22222e;
  --border: rgba(255, 255, 255, 0.08);
  --text: #f0f0f5;
  --text-muted: #8b8b9e;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --accent: #60a5fa;
  --zalo: #0068ff;
  --zalo-hover: #0050cc;
  --gradient-start: #3b82f6;
  --gradient-end: #8b5cf6;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --transition: 0.2s ease;
}

html {
  scroll-behavior: smooth;
}

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

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--text);
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
}

.logo-icon {
  font-size: 1.4rem;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 28px;
  margin-left: auto;
}

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

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

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.9rem;
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 14px 28px;
  font-size: 1rem;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.4);
}

.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  background: var(--surface);
  color: var(--text);
  border-color: rgba(255, 255, 255, 0.15);
}

.btn-zalo {
  background: var(--zalo);
  color: #fff;
  width: 100%;
  margin-top: 16px;
}

.btn-zalo:hover {
  background: var(--zalo-hover);
  color: #fff;
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(59, 130, 246, 0.18), transparent),
    radial-gradient(ellipse 60% 50% at 80% 60%, rgba(139, 92, 246, 0.12), transparent);
  pointer-events: none;
}

.hero-content {
  position: relative;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(59, 130, 246, 0.15);
  border: 1px solid rgba(59, 130, 246, 0.3);
  border-radius: 100px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}

.gradient-text {
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-highlights {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  max-width: 720px;
  margin: 0 auto 40px;
}

.highlight-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 16px 18px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: left;
  transition: all var(--transition);
}

.highlight-item:hover {
  background: rgba(59, 130, 246, 0.08);
  border-color: rgba(59, 130, 246, 0.25);
  transform: translateY(-2px);
}

.highlight-item-wide {
  grid-column: 1 / -1;
  justify-content: center;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(139, 92, 246, 0.08));
  border-color: rgba(59, 130, 246, 0.2);
}

.highlight-icon {
  font-size: 1.4rem;
  line-height: 1;
  flex-shrink: 0;
}

.highlight-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.highlight-text strong {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
}

.highlight-text span {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.highlight-text a {
  color: var(--accent);
  font-weight: 600;
}

.highlight-text a:hover {
  color: var(--text);
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.hero-stats {
  display: flex;
  gap: 48px;
  justify-content: center;
  flex-wrap: wrap;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.stat-value {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text);
}

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

/* Sections */
.section {
  padding: 100px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-header h2 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.section-header p {
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto;
  font-size: 1.05rem;
}

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 32px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: all var(--transition);
}

.card:hover {
  border-color: rgba(59, 130, 246, 0.3);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* Notice */
.notice {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: rgba(251, 191, 36, 0.08);
  border: 1px solid rgba(251, 191, 36, 0.25);
  border-radius: var(--radius);
  padding: 20px 24px;
}

.notice-icon {
  font-size: 1.4rem;
  flex-shrink: 0;
}

.notice strong {
  display: block;
  margin-bottom: 4px;
  color: #fbbf24;
}

.notice p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Steps */
.steps {
  display: flex;
  flex-direction: column;
  gap: 0;
  max-width: 720px;
  margin: 0 auto;
}

.step {
  display: flex;
  gap: 24px;
  padding: 32px 0;
  border-bottom: 1px solid var(--border);
  position: relative;
}

.step:last-child {
  border-bottom: none;
}

.step-number {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  border-radius: 14px;
  font-weight: 800;
  font-size: 0.9rem;
  color: #fff;
}

.step-content h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.step-content p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

.step-content .btn-download {
  margin-top: 16px;
  background: rgba(34, 197, 94, 0.15);
  color: #4ade80;
  border: 1px solid rgba(34, 197, 94, 0.35);
}

.step-content .btn-download:hover {
  background: rgba(34, 197, 94, 0.25);
  color: #86efac;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(34, 197, 94, 0.2);
}

.step-highlight {
  color: #60a5fa;
}

.tool-guide {
  margin-top: 16px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: #fff;
}

.tool-guide img {
  display: block;
  width: 100%;
  max-width: 520px;
  height: auto;
}

.tool-guide figcaption {
  padding: 10px 14px;
  font-size: 0.8rem;
  color: var(--text-muted);
  background: var(--surface);
  text-align: center;
}

.step-example {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 12px;
  padding: 10px 16px;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.25);
  border-radius: 8px;
}

.step-example-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.step-example code {
  font-family: 'Inter', monospace;
  font-size: 1rem;
  font-weight: 700;
  color: #4ade80;
  letter-spacing: 0.05em;
}

.btn-step {
  margin-top: 14px;
  width: auto;
  display: inline-flex;
}

.step-note {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-top: 14px;
  padding: 12px 16px;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: 8px;
}

.step-note span {
  font-size: 1.1rem;
  flex-shrink: 0;
}

.step-note p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* Pricing Tabs */
.price-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 24px;
}

.price-tab {
  padding: 12px 28px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

.price-tab:hover {
  color: var(--text);
  border-color: rgba(255, 255, 255, 0.15);
}

.price-tab.active {
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.35);
}

.price-panel {
  display: none;
}

.price-panel.active {
  display: block;
}

/* Pricing Table */
.price-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.price-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  min-width: 480px;
}

.price-table thead tr {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.2), rgba(139, 92, 246, 0.15));
}

.price-table th {
  padding: 16px 18px;
  text-align: left;
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--text);
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
  background: inherit;
}

.price-table th:not(:first-child) {
  text-align: right;
}

.price-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}

.price-table tbody tr:last-child td {
  border-bottom: none;
}

.price-table tbody tr:hover {
  background: rgba(59, 130, 246, 0.05);
}

.price-name {
  color: var(--text);
  font-weight: 500;
  line-height: 1.5;
  min-width: 320px;
}

.price-col {
  text-align: right;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.price-highlight {
  color: #4ade80;
  font-weight: 700;
}

.price-note {
  margin-top: 20px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 800px;
  margin: 0 auto;
  align-items: start;
}

.contact-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.contact-card-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}

.contact-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  font-size: 1.5rem;
}

.zalo-icon {
  background: rgba(0, 104, 255, 0.15);
  color: var(--zalo);
}

.bank-icon {
  background: rgba(34, 197, 94, 0.15);
}

.contact-card-header h3 {
  font-size: 1.1rem;
  font-weight: 700;
}

.contact-card-header p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.contact-value {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: 0.02em;
}

.contact-value:hover {
  color: var(--zalo);
}

.qr-wrapper {
  display: flex;
  justify-content: center;
  margin-bottom: 20px;
}

.qr-image {
  width: 220px;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #fff;
}

.bank-info {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.bank-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.bank-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  min-width: 110px;
}

.bank-value {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  font-family: 'Inter', monospace;
  letter-spacing: 0.05em;
}

.bank-note {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0;
}

.copy-btn {
  background: var(--surface-hover);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 8px;
  cursor: pointer;
  color: var(--text-muted);
  transition: all var(--transition);
  display: flex;
  align-items: center;
}

.copy-btn:hover {
  color: var(--text);
  border-color: rgba(255, 255, 255, 0.2);
}

.copy-btn.copied {
  color: #22c55e;
  border-color: rgba(34, 197, 94, 0.4);
}

/* Footer */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  color: var(--text-muted);
}

.footer-copy {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Float Zalo */
.float-zalo {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 56px;
  height: 56px;
  background: var(--zalo);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 4px 20px rgba(0, 104, 255, 0.5);
  z-index: 99;
  transition: all var(--transition);
  animation: pulse 2.5s infinite;
}

.float-zalo:hover {
  background: var(--zalo-hover);
  color: #fff;
  transform: scale(1.08);
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 4px 20px rgba(0, 104, 255, 0.5); }
  50% { box-shadow: 0 4px 32px rgba(0, 104, 255, 0.8); }
}

/* Mobile nav */
.nav.open .nav-links {
  display: flex;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
    gap: 16px;
    margin-left: 0;
  }

  .nav.open .nav-links {
    display: flex;
  }

  .nav .btn-primary.btn-sm {
    display: none;
  }

  .menu-toggle {
    display: flex;
    margin-left: auto;
  }

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

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

  .hero-highlights {
    grid-template-columns: 1fr;
    max-width: 400px;
  }

  .highlight-item-wide {
    grid-column: auto;
  }

  .hero-stats {
    gap: 32px;
  }

  .step {
    flex-direction: column;
    gap: 16px;
  }

  .section {
    padding: 72px 0;
  }
}