:root {
  /* Color palette */
  --bg-base: #020617;
  --bg-card: #0f172a;
  --border: #1e293b;
  --text-main: #f8fafc;
  --text-secondary: #94a3b8;
  --text-dim: #64748b;

  /* Accent colors */
  --accent-security: #3b82f6;
  --accent-medical: #06b6d4;
  --accent-alert: #ef4444;
  --accent-success: #10b981;

  /* Typography */
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-display: 'Orbitron', sans-serif;
  --font-mono: 'Courier New', 'Consolas', monospace;
}

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

body {
  font-family: var(--font-main);
  background-color: var(--bg-base);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  font-size: 16px;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
}

/* Navigation */
nav {
  position: fixed;
  top: 0;
  width: 100%;
  height: 70px;
  background: rgba(2, 6, 23, 0.95);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 40px;
}

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

.logo img {
  height: 45px;
  width: auto;
}

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

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  transition: color 0.2s;
  padding-bottom: 2px;
}

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

/* Main container */
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 100px 40px 60px;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 14px 28px;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-decoration: none;
  border-radius: 4px;
  transition: all 0.3s;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent-security);
  color: white;
}

.btn-primary:hover {
  background: #2563eb;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
  background: transparent;
  color: var(--text-main);
  border: 2px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--accent-security);
  color: var(--accent-security);
}

/* Cards */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 32px;
  transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

/* Panel styling for demos */
.panel {
  background: rgba(15, 23, 42, 0.95);
  padding: 20px;
  border-radius: 4px;
  border: 1px solid var(--border);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(10px);
}

/* Footer */
footer {
  padding: 60px 40px;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
  background: var(--bg-base);
  margin-top: 80px;
}

/* Utility classes */
.text-secondary {
  color: var(--text-secondary);
}

.text-dim {
  color: var(--text-dim);
}

.mb-4 {
  margin-bottom: 1.5rem;
}

.mb-8 {
  margin-bottom: 3rem;
}

.mt-4 {
  margin-top: 1.5rem;
}

/* Responsive */
@media (max-width: 768px) {
  nav {
    padding: 0 20px;
  }

  .nav-links {
    display: none;
  }

  .container {
    padding: 80px 20px 40px;
  }

  h1 {
    font-size: 1.8rem !important;
  }
}