/* ==========================================================================
   HEALTHCARE TECH STRATEGY & ARCHITECTURE - CORE DESIGN SYSTEM
   ========================================================================== */

:root {
  /* Brand Clinical Tech Palette */
  --bg-primary: #080d1a;
  --bg-secondary: #0d1527;
  --bg-card: rgba(16, 26, 49, 0.72);
  --bg-card-hover: rgba(22, 36, 68, 0.85);
  --bg-glass: rgba(13, 21, 39, 0.85);
  --bg-glass-subtle: rgba(255, 255, 255, 0.03);

  /* Borders & Accents */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-glass: rgba(45, 212, 191, 0.2);
  --border-glow: rgba(34, 211, 238, 0.35);

  /* Typography Colors */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-highlight: #38bdf8;
  
  /* Primary & Accents */
  --teal-400: #14b8a6;
  --teal-300: #2dd4bf;
  --cyan-400: #22d3ee;
  --cyan-500: #06b6d4;
  --blue-500: #3b82f6;
  --emerald-400: #34d399;
  --amber-400: #fbbf24;

  /* Gradients */
  --grad-primary: linear-gradient(135deg, #14b8a6 0%, #06b6d4 50%, #3b82f6 100%);
  --grad-clinical: linear-gradient(135deg, #0d9488 0%, #0284c7 100%);
  --grad-card: linear-gradient(180deg, rgba(20, 34, 62, 0.6) 0%, rgba(10, 18, 34, 0.85) 100%);
  --grad-badge: linear-gradient(90deg, rgba(20, 184, 166, 0.15) 0%, rgba(6, 182, 212, 0.15) 100%);
  --grad-hero-glow: radial-gradient(circle at 50% 15%, rgba(6, 182, 212, 0.15) 0%, rgba(8, 13, 26, 0) 70%);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px -4px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 16px 40px -8px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 25px rgba(34, 211, 238, 0.2);
  --shadow-teal: 0 0 25px rgba(20, 184, 166, 0.25);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', Consolas, Monaco, monospace;

  /* Layout Spacing */
  --container-max: 1240px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  /* Transitions */
  --trans-fast: 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  --trans-base: 0.28s cubic-bezier(0.16, 1, 0.3, 1);
  --trans-slow: 0.45s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  color-scheme: dark;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(6, 182, 212, 0.07) 0%, transparent 40%),
    radial-gradient(circle at 90% 60%, rgba(20, 184, 166, 0.05) 0%, transparent 45%),
    linear-gradient(to bottom, #080d1a, #091021);
  background-attachment: fixed;
}

/* Subtle Technical Grid Background */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(rgba(255, 255, 255, 0.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.018) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

/* Focus States for WCAG 2.1 AA Accessibility */
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 3px;
}

/* Typography Utilities */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.025em;
}

h1 { font-size: clamp(2.1rem, 4.5vw + 0.5rem, 3.75rem); }
h2 { font-size: clamp(1.75rem, 3vw + 0.5rem, 2.65rem); }
h3 { font-size: clamp(1.25rem, 2vw + 0.25rem, 1.65rem); }
h4 { font-size: 1.15rem; }

p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.7;
}

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

.text-mono {
  font-family: var(--font-mono);
  font-size: 0.9em;
  letter-spacing: -0.01em;
}

/* Layout Containers */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: clamp(1rem, 4vw, 2rem);
  padding-right: clamp(1rem, 4vw, 2rem);
  position: relative;
  z-index: 1;
}

.section {
  padding-top: clamp(4rem, 8vw, 7.5rem);
  padding-bottom: clamp(4rem, 8vw, 7.5rem);
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 780px;
  margin: 0 auto clamp(2.5rem, 5vw, 4.5rem) auto;
}

.section-header p {
  margin-top: 1rem;
  font-size: 1.125rem;
}

/* Pill Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.375rem 0.875rem;
  background: var(--grad-badge);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--teal-300);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.badge-pulse {
  width: 8px;
  height: 8px;
  background-color: var(--emerald-400);
  border-radius: 50%;
  display: inline-block;
  box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.7);
  animation: pulse-ring 2s infinite cubic-bezier(0.45, 0, 0.2, 1);
}

@keyframes pulse-ring {
  0% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.7); }
  70% { box-shadow: 0 0 0 8px rgba(52, 211, 153, 0); }
  100% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0); }
}

/* Button Component System (48px+ touch targets for mobile) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.625rem;
  padding: 0.75rem 1.625rem;
  min-height: 48px;
  border-radius: var(--radius-sm);
  font-size: 0.975rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--trans-base);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: var(--grad-clinical);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.15);
  box-shadow: 0 4px 16px rgba(13, 148, 136, 0.35);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #0f766e 0%, #0369a1 100%);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(13, 148, 136, 0.45);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--border-glass);
  color: var(--cyan-400);
  transform: translateY(-2px);
}

.btn-outline-cyan {
  background: transparent;
  color: var(--cyan-400);
  border: 1px solid rgba(34, 211, 238, 0.4);
}

.btn-outline-cyan:hover {
  background: rgba(34, 211, 238, 0.1);
  border-color: var(--cyan-400);
  box-shadow: var(--shadow-glow);
}

.btn-sm {
  min-height: 40px;
  padding: 0.45rem 1rem;
  font-size: 0.875rem;
}

.btn-full-mobile {
  width: 100%;
}

@media (min-width: 640px) {
  .btn-full-mobile {
    width: auto;
  }
}

/* Glassmorphic Cards */
.card {
  background: var(--grad-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: clamp(1.25rem, 3vw, 2rem);
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  transition: transform var(--trans-base), border-color var(--trans-base), box-shadow var(--trans-base);
  position: relative;
  overflow: hidden;
}

.card:hover {
  border-color: var(--border-glass);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

/* Decorative subtle top highlight line on cards */
.card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(34, 211, 238, 0.25), transparent);
}