/* ==========================================================================
   DH SOFTWARE - UNIFIED BRAND DESIGN SYSTEM (DARK TECH THEME)
   Rule 60-30-10: 60% Navy (#0A1529), 30% Deep Blue (#203D71), 10% Cyber Blue (#0291F9)
   Typography: Be Vietnam Pro (Primary Friendly Font), Fira Code (Codes / Tokens)
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;1,400&family=Fira+Code:wght@400;600;700&family=Inter:wght@400;500;600;700&display=swap');

:root {
  /* Brand Core Colors */
  --dh-navy: #0A1529;
  --dh-navy-dark: #060D1A;
  --dh-deep-blue: #203D71;
  --dh-deep-blue-surface: rgba(32, 61, 113, 0.35);
  --dh-deep-blue-hover: rgba(32, 61, 113, 0.65);
  --dh-cyber-blue: #0291F9;
  --dh-cyber-blue-hover: #0077D6;
  --dh-cyber-blue-glow: rgba(2, 145, 249, 0.4);
  --dh-cyber-blue-subtle: rgba(2, 145, 249, 0.12);

  /* Contrast & Neutral */
  --dh-paper: #FFFFFF;
  --dh-text-primary: #F8FAFC;
  --dh-text-secondary: #94A3B8;
  --dh-text-muted: #64748B;
  --dh-border: rgba(255, 255, 255, 0.1);
  --dh-border-accent: rgba(2, 145, 249, 0.3);

  /* Semantics */
  --dh-success: #10B981;
  --dh-success-glow: rgba(16, 185, 129, 0.25);
  --dh-warning: #F59E0B;
  --dh-danger: #EF4444;
  --dh-info: #38BDF8;

  /* Typography */
  --font-primary: 'Inter', system-ui, -apple-system, sans-serif;
  --font-heading: 'Plus Jakarta Sans', 'Inter', system-ui, sans-serif;
  --font-mono: 'Fira Code', 'JetBrains Mono', Consolas, monospace;

  /* Transitions & Shadows */
  --dh-transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --dh-shadow-card: 0 10px 30px -5px rgba(0, 0, 0, 0.5), 0 0 1px 1px rgba(255, 255, 255, 0.05);
  --dh-shadow-glow: 0 0 25px var(--dh-cyber-blue-glow);
}

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

body {
  font-family: var(--font-primary);
  background-color: var(--dh-navy);
  color: var(--dh-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(2, 145, 249, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 85% 65%, rgba(32, 61, 113, 0.25) 0%, transparent 50%),
    radial-gradient(circle at 50% 90%, rgba(2, 145, 249, 0.05) 0%, transparent 40%);
  background-attachment: fixed;
}

/* Typography Hierarchy */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--dh-paper);
  letter-spacing: -0.02em;
  line-height: 1.25;
}

h1 { font-size: 2.75rem; }
h2 { font-size: 2.15rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
  color: var(--dh-text-secondary);
  font-size: 1rem;
}

a {
  color: var(--dh-cyber-blue);
  text-decoration: none;
  transition: var(--dh-transition);
}

a:hover {
  color: #38BDF8;
  text-shadow: 0 0 8px var(--dh-cyber-blue-glow);
}

code, pre, .font-mono {
  font-family:'Montserrat', sans-serif;
}

/* Layout Containers */
.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Navigation Header */
.dh-navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10, 21, 41, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--dh-border-accent);
  padding: 14px 0;
}

.dh-nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.dh-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.dh-brand img {
  height: 44px;
  width: auto;
  filter: drop-shadow(0 0 8px var(--dh-cyber-blue-glow));
}

.dh-brand-text {
  display: flex;
  flex-direction: column;
}

.dh-brand-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--dh-paper);
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 6px;
}

.dh-brand-name span {
  color: var(--dh-cyber-blue);
}

.dh-brand-slogan {
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--dh-text-secondary);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.dh-nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.dh-nav-links a {
  color: var(--dh-text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
}

.dh-nav-links a:hover,
.dh-nav-links a.active {
  color: var(--dh-paper);
}

/* Buttons System */
.dh-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: 8px;
  font-family:'Montserrat', sans-serif;
  font-weight: 600;
  font-size: 0.92rem;
  cursor: pointer;
  border: 1px solid transparent;
  transition: var(--dh-transition);
  text-decoration: none;
  white-space: nowrap;
}

.dh-btn-primary {
  background: linear-gradient(135deg, #0291F9 0%, #0077D6 100%);
  color: #FFFFFF;
  box-shadow: 0 4px 15px var(--dh-cyber-blue-glow);
}

.dh-btn-primary:hover {
  background: linear-gradient(135deg, #24A2FF 0%, #0291F9 100%);
  color: #FFFFFF;
  box-shadow: 0 6px 20px rgba(2, 145, 249, 0.6);
  transform: translateY(-2px);
}

.dh-btn-secondary {
  background: var(--dh-deep-blue-surface);
  color: var(--dh-paper);
  border-color: var(--dh-border-accent);
}

.dh-btn-secondary:hover {
  background: var(--dh-deep-blue-hover);
  border-color: var(--dh-cyber-blue);
  color: #FFFFFF;
  transform: translateY(-2px);
}

.dh-btn-outline {
  background: transparent;
  color: var(--dh-cyber-blue);
  border-color: var(--dh-cyber-blue);
}

.dh-btn-outline:hover {
  background: var(--dh-cyber-blue-subtle);
  color: #FFFFFF;
}

.dh-btn-sm {
  padding: 6px 14px;
  font-size: 0.82rem;
  border-radius: 6px;
}

.dh-btn-lg {
  padding: 14px 28px;
  font-size: 1.05rem;
  border-radius: 10px;
}

/* Hero Section */
.dh-hero {
  padding: 70px 0 60px;
  text-align: center;
  position: relative;
}

.dh-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--dh-cyber-blue-subtle);
  border: 1px solid var(--dh-border-accent);
  border-radius: 9999px;
  color: var(--dh-cyber-blue);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 24px;
}

.dh-hero-title {
  font-size: 3.5rem;
  margin-bottom: 20px;
  line-height: 1.15;
}

.dh-hero-title .highlight {
  background: linear-gradient(135deg, #0291F9 0%, #38BDF8 60%, #FFFFFF 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.dh-hero-subtitle {
  font-size: 1.25rem;
  max-width: 760px;
  margin: 0 auto 36px;
  color: var(--dh-text-secondary);
}

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

/* Cards & Surface Components */
.dh-card {
  background: var(--dh-deep-blue-surface);
  border: 1px solid var(--dh-border-accent);
  border-radius: 16px;
  padding: 24px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--dh-shadow-card);
  transition: var(--dh-transition);
}

.dh-card:hover {
  border-color: var(--dh-cyber-blue);
  box-shadow: 0 12px 35px -5px rgba(0, 0, 0, 0.6), 0 0 20px var(--dh-cyber-blue-glow);
  transform: translateY(-4px);
}

/* Product Showcase Grid */
.dh-section-header {
  text-align: center;
  margin-bottom: 48px;
}

.dh-section-title {
  font-size: 2.25rem;
  margin-bottom: 12px;
}

.dh-grid-tools {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 24px;
  margin-bottom: 70px;
}

.dh-tool-card {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.dh-tool-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 16px;
}

.dh-tool-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: var(--dh-cyber-blue-subtle);
  border: 1px solid var(--dh-border-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--dh-cyber-blue);
  font-size: 1.5rem;
}

.dh-tool-version {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 8px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.08);
  color: var(--dh-text-secondary);
}

.dh-tool-title {
  font-size: 1.35rem;
  margin-bottom: 8px;
  color: var(--dh-paper);
}

.dh-tool-desc {
  font-size: 0.92rem;
  color: var(--dh-text-secondary);
  margin-bottom: 20px;
  flex-grow: 1;
}

.dh-tool-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 20px;
}

.dh-tool-tag {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 4px;
  background: rgba(32, 61, 113, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.06);
  color: #CBD5E1;
}

.dh-tool-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.dh-tool-price {
  font-weight: 700;
  color: var(--dh-paper);
}

.dh-tool-price span {
  font-size: 0.8rem;
  color: var(--dh-text-secondary);
  font-weight: 400;
}

/* Decoy Pricing Section */
.dh-pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
  align-items: center;
  margin-bottom: 80px;
}

.dh-pricing-card {
  position: relative;
  background: var(--dh-deep-blue-surface);
  border: 1px solid var(--dh-border-accent);
  border-radius: 20px;
  padding: 36px 28px;
  text-align: center;
  transition: var(--dh-transition);
}

.dh-pricing-card.featured {
  background: linear-gradient(180deg, rgba(32, 61, 113, 0.6) 0%, rgba(10, 21, 41, 0.8) 100%);
  border: 2px solid var(--dh-cyber-blue);
  box-shadow: 0 0 35px var(--dh-cyber-blue-glow);
  transform: scale(1.04);
}

.dh-pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #0291F9 0%, #0077D6 100%);
  color: #FFFFFF;
  padding: 4px 16px;
  border-radius: 9999px;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  box-shadow: 0 2px 10px var(--dh-cyber-blue-glow);
}

.dh-plan-name {
  font-size: 1.4rem;
  margin-bottom: 8px;
}

.dh-plan-desc {
  font-size: 0.88rem;
  margin-bottom: 24px;
  color: var(--dh-text-secondary);
}

.dh-plan-price {
  font-size: 2.75rem;
  font-weight: 800;
  color: var(--dh-paper);
  margin-bottom: 6px;
}

.dh-plan-price small {
  font-size: 1rem;
  font-weight: 500;
  color: var(--dh-text-secondary);
}

.dh-plan-savings {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--dh-success);
  margin-bottom: 24px;
}

.dh-plan-features {
  list-style: none;
  text-align: left;
  margin-bottom: 32px;
}

.dh-plan-features li {
  font-size: 0.92rem;
  color: var(--dh-text-primary);
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.dh-plan-features li svg {
  color: var(--dh-cyber-blue);
  flex-shrink: 0;
}

/* Forms & Inputs */
.dh-form-group {
  margin-bottom: 18px;
  text-align: left;
}

.dh-label {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--dh-text-primary);
  margin-bottom: 8px;
}

.dh-input, .dh-select, .dh-textarea {
  width: 100%;
  padding: 12px 16px;
  background: rgba(10, 21, 41, 0.85);
  border: 1px solid var(--dh-border-accent);
  border-radius: 8px;
  color: var(--dh-paper);
  font-family:'Montserrat', sans-serif;
  font-size: 0.95rem;
  transition: var(--dh-transition);
}

.dh-input:focus, .dh-select:focus, .dh-textarea:focus {
  outline: none;
  border-color: var(--dh-cyber-blue);
  box-shadow: 0 0 12px var(--dh-cyber-blue-glow);
}

/* Checkout VietQR Box */
.dh-qr-box {
  background: #FFFFFF;
  padding: 18px;
  border-radius: 14px;
  display: inline-block;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.4);
}

.dh-qr-box img {
  width: 240px;
  height: 240px;
  display: block;
}

.dh-countdown {
  font-family:'Montserrat', sans-serif;
  font-size: 1.35rem;
  color: var(--dh-warning);
  font-weight: 700;
}

.dh-token-display {
  background: var(--dh-navy-dark);
  border: 1px dashed var(--dh-cyber-blue);
  border-radius: 8px;
  padding: 16px;
  font-family:'Montserrat', sans-serif;
  font-size: 0.85rem;
  color: #38BDF8;
  word-break: break-all;
  user-select: all;
  margin: 16px 0;
}

/* Footer */
.dh-footer {
  background: var(--dh-navy-dark);
  border-top: 1px solid var(--dh-border-accent);
  padding: 48px 0 24px;
  margin-top: 80px;
}

.dh-footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.85rem;
  color: var(--dh-text-muted);
}

/* Responsive */
@media (max-width: 768px) {
  .dh-hero-title { font-size: 2.25rem; }
  .dh-nav-links { display: none; }
  .dh-grid-tools { grid-template-columns: 1fr; }
  .dh-pricing-card.featured { transform: none; }
}