/* ==========================================================================
   Base Design Tokens & Resets
   Secure Medical QR Prototype
   ========================================================================== */

:root {
  /* Color Palette - High Contrast & Accessible */
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-surface-hover: #f1f5f9;
  --color-border: #cbd5e1;
  --color-border-subtle: #e2e8f0;

  --color-text-main: #0f172a;
  --color-text-muted: #475569;
  --color-text-light: #64748b;
  --color-text-inverse: #ffffff;

  /* Accent & Status Colors */
  --color-primary: #0284c7;
  --color-primary-hover: #0369a1;
  --color-primary-bg: #e0f2fe;

  --color-danger: #dc2626;
  --color-danger-hover: #b91c1c;
  --color-danger-bg: #fee2e2;
  --color-danger-border: #fca5a5;

  --color-warning: #d97706;
  --color-warning-hover: #b45309;
  --color-warning-bg: #fef3c7;
  --color-warning-border: #fcd34d;

  --color-success: #16a34a;
  --color-success-hover: #15803d;
  --color-success-bg: #dcfce7;
  --color-success-border: #86efac;

  /* Typography */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;

  /* Radii & Shadows */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);

  --max-width-content: 1100px;
  --max-width-emergency: 580px;
}

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text-main);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--color-text-main);
  line-height: 1.25;
  font-weight: 700;
}

h1 { font-size: 1.875rem; margin-bottom: var(--space-4); }
h2 { font-size: 1.5rem; margin-bottom: var(--space-3); }
h3 { font-size: 1.25rem; margin-bottom: var(--space-2); }

p {
  margin-bottom: var(--space-4);
  color: var(--color-text-muted);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Screen reader only utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--max-width-content);
  margin-left: auto;
  margin-right: auto;
  padding: var(--space-4);
}

/* Nav header */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border-subtle);
  box-shadow: var(--shadow-sm);
}

.site-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-3) var(--space-4);
  max-width: var(--max-width-content);
  margin: 0 auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-text-main);
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-badge {
  font-size: 0.75rem;
  background: var(--color-danger-bg);
  color: var(--color-danger);
  border: 1px solid var(--color-danger-border);
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-weight: 600;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-subtle);
  padding: var(--space-6) var(--space-4);
  margin-top: auto;
  font-size: 0.875rem;
  color: var(--color-text-light);
  text-align: center;
}

.footer-notice {
  font-weight: 600;
  color: var(--color-danger);
  margin-bottom: var(--space-2);
}