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

:root {
  --primary-color: #407CE0;
  --primary-dark: #2c5ba3;
  --secondary-color: #10b981;
  --background: #f8fafc;
  --surface: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --border: #e2e8f0;
  --success: #10b981;
  --gradient: linear-gradient(135deg, #407CE0 0%, #0ea5e9 100%);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #0f172a;
    --surface: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border: #334155;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
  }
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--background);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
  transition: background-color 0.3s, color 0.3s;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.content {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 20px;
}

.logo {
  width: 120px;
  height: 120px;
  border-radius: 28px;
  margin-bottom: 32px;
  box-shadow: var(--shadow-lg);
}

h1 {
  font-size: 3rem;
  font-weight: 800;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.tagline {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 48px;
  font-weight: 500;
}

.download-section {
  margin: 20px 0 60px;
  width: 100%;
  max-width: 400px;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 16px 32px;
  font-size: 1.1rem;
  font-weight: 600;
  color: white;
  background: var(--gradient);
  border: none;
  border-radius: 16px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  width: 100%;
  max-width: 300px;
  box-shadow: 0 4px 12px rgba(64, 124, 224, 0.3);
}

.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 16px rgba(64, 124, 224, 0.4);
}

.download-btn:active {
  transform: translateY(0);
}

.download-btn svg {
  width: 24px;
  height: 24px;
}

.qr-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.qr-codes {
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
  justify-content: center;
}

.qr-code {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.qr-code-image {
  width: 180px;
  height: 180px;
  background: white;
  padding: 12px;
  border-radius: 20px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
}

.qr-code-image canvas, .qr-code-image img {
  width: 100%;
  height: 100%;
  border-radius: 8px;
}

.qr-label {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 32px;
  width: 100%;
  max-width: 1000px;
}

.feature {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 32px;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  text-align: left;
  box-shadow: var(--shadow-sm);
}

.feature:hover {
  transform: translateY(-4px);
  border-color: var(--primary-color);
  box-shadow: var(--shadow);
}

.feature .icon {
  font-size: 2.5rem;
  display: block;
  margin-bottom: 20px;
}

.feature h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.feature p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.6;
}

footer {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
  margin-top: 80px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
}

.footer-links {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: center;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}

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

.separator {
  color: var(--border);
}

/* Responsive */
@media (max-width: 768px) {
  h1 {
    font-size: 2.25rem;
  }

  .tagline {
    font-size: 1.1rem;
    margin-bottom: 40px;
  }
  
  .content {
    padding: 40px 20px;
  }

  .features {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .feature {
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 20px;
    text-align: left;
  }
  
  .feature .icon {
    margin-bottom: 0;
    font-size: 2rem;
  }
  
  .feature div {
     flex: 1;
  }

  .qr-codes {
    flex-direction: column;
    gap: 30px;
  }
}

/* Loading animation */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}