/* ===================================
   AI Platform Privacy Policy
   Modern CSS (2025 Standards)
   =================================== */

/* ===================================
   CSS Custom Properties (Design Tokens)
   =================================== */
:root {
  /* Typography Scale - Fluid with clamp() */
  --font-size-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --font-size-sm: clamp(0.875rem, 0.825rem + 0.25vw, 1rem);
  --font-size-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --font-size-lg: clamp(1.125rem, 1.05rem + 0.375vw, 1.25rem);
  --font-size-xl: clamp(1.25rem, 1.15rem + 0.5vw, 1.5rem);
  --font-size-2xl: clamp(1.5rem, 1.35rem + 0.75vw, 1.875rem);
  --font-size-3xl: clamp(1.875rem, 1.65rem + 1.125vw, 2.25rem);
  --font-size-4xl: clamp(2.25rem, 1.95rem + 1.5vw, 3rem);

  /* Font Weights */
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* Line Heights */
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing Scale (8px base) */
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */

  /* Modern Color Palette */
  --color-primary: #6366f1;
  --color-primary-hover: #4f46e5;
  --color-primary-light: #818cf8;
  --color-primary-dark: #3730a3;

  --color-success: #10b981;
  --color-success-light: #d1fae5;
  --color-info: #3b82f6;
  --color-info-light: #dbeafe;
  --color-warning: #f59e0b;
  --color-warning-light: #fef3c7;

  /* Neutral Colors */
  --color-white: #ffffff;
  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2937;
  --color-gray-900: #111827;

  /* Semantic Colors */
  --color-text-primary: var(--color-gray-900);
  --color-text-secondary: var(--color-gray-600);
  --color-text-muted: var(--color-gray-500);
  --color-background: var(--color-white);
  --color-background-alt: var(--color-gray-50);
  --color-border: var(--color-gray-200);

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 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);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Container Width */
  --container-max-width: 56rem; /* 896px */
}

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-gray-50);
  min-height: 100vh;
}

/* ===================================
   Skip Link (Accessibility)
   =================================== */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  z-index: 100;
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-primary);
  color: var(--color-white);
  text-decoration: none;
  font-weight: var(--font-weight-semibold);
  border-radius: 0 0 var(--radius-md) 0;
}

.skip-link:focus {
  top: 0;
}

/* ===================================
   Container
   =================================== */
.container {
  max-width: var(--container-max-width);
  margin-inline: auto;
  padding-inline: var(--space-4);
  background-color: var(--color-background);
  box-shadow: var(--shadow-md);
  min-height: 100vh;
}

@media (min-width: 48rem) {
  .container {
    padding-inline: var(--space-6);
  }
}

/* ===================================
   Header
   =================================== */
.page-header {
  padding-block: var(--space-12);
  text-align: center;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-white);
  margin-inline: calc(-1 * var(--space-4));
  margin-block-start: 0;
  margin-block-end: var(--space-12);
}

@media (min-width: 48rem) {
  .page-header {
    margin-inline: calc(-1 * var(--space-6));
    padding-block: var(--space-16);
  }
}

.page-header h1 {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  margin-block-end: var(--space-3);
  letter-spacing: -0.025em;
}

.last-updated {
  font-size: var(--font-size-sm);
  opacity: 0.9;
  font-style: italic;
  font-weight: var(--font-weight-normal);
}

/* ===================================
   Typography
   =================================== */
main h2 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  margin-block-start: var(--space-12);
  margin-block-end: var(--space-6);
  padding-block-end: var(--space-3);
  border-block-end: 2px solid var(--color-primary);
  line-height: var(--line-height-tight);
}

main h3 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-block-start: var(--space-8);
  margin-block-end: var(--space-4);
  line-height: var(--line-height-tight);
}

main h4 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-gray-700);
  margin-block-start: var(--space-6);
  margin-block-end: var(--space-3);
  line-height: var(--line-height-tight);
}

p {
  margin-block-end: var(--space-4);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

strong {
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
}

/* ===================================
   Sections & Articles
   =================================== */
section {
  margin-block-end: var(--space-12);
  scroll-margin-block-start: var(--space-4);
}

article {
  margin-block-end: var(--space-8);
}

.subsection {
  margin-inline-start: var(--space-6);
  padding-inline-start: var(--space-4);
  border-inline-start: 3px solid var(--color-gray-200);
}

/* Visually hidden but accessible to screen readers */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* ===================================
   Introduction Section
   =================================== */
.intro {
  background-color: var(--color-info-light);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border-inline-start: 4px solid var(--color-info);
  margin-block-end: var(--space-10);
}

.intro p {
  color: var(--color-text-primary);
}

.intro p:last-child {
  margin-block-end: 0;
}

/* ===================================
   Table of Contents
   =================================== */
.table-of-contents {
  background-color: var(--color-background-alt);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  margin-block-end: var(--space-10);
  border: 1px solid var(--color-border);
}

.table-of-contents h2 {
  color: var(--color-primary);
  font-size: var(--font-size-xl);
  margin-block: 0 var(--space-4);
  padding-block-end: 0;
  border-block-end: none;
}

.table-of-contents ol {
  list-style-position: inside;
  padding: 0;
  counter-reset: toc-counter;
}

.table-of-contents li {
  counter-increment: toc-counter;
  margin-block-end: var(--space-3);
  padding: var(--space-3);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.table-of-contents li::marker {
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
}

.table-of-contents li:hover {
  background-color: var(--color-info-light);
}

.table-of-contents a {
  color: var(--color-text-primary);
  text-decoration: none;
  font-weight: var(--font-weight-medium);
  transition: color var(--transition-fast);
}

.table-of-contents a:hover {
  color: var(--color-primary);
}

.table-of-contents a:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ===================================
   Lists
   =================================== */
ul,
ol {
  margin-inline-start: var(--space-6);
  margin-block-end: var(--space-4);
}

li {
  margin-block-end: var(--space-2);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

li ul,
li ol {
  margin-block-start: var(--space-2);
  margin-block-end: var(--space-2);
}

/* ===================================
   Callouts
   =================================== */
.callout {
  padding: var(--space-4);
  border-radius: var(--radius-md);
  margin-block: var(--space-4);
  font-weight: var(--font-weight-medium);
  border-inline-start: 4px solid;
}

.callout-info {
  background-color: var(--color-info-light);
  border-inline-start-color: var(--color-info);
  color: var(--color-gray-800);
}

.callout-success {
  background-color: var(--color-success-light);
  border-inline-start-color: var(--color-success);
  color: var(--color-gray-800);
}

/* ===================================
   Service Cards
   =================================== */
.service-card {
  background-color: var(--color-background-alt);
  padding: var(--space-6);
  margin-block: var(--space-5);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition-base);
}

.service-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.service-card h4 {
  color: var(--color-primary);
  margin-block: 0 var(--space-4);
  font-size: var(--font-size-lg);
}

.service-card dl {
  display: grid;
  gap: var(--space-3);
}

.service-card dt {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.service-card dd {
  margin-inline-start: 0;
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

/* ===================================
   Rights Grid
   =================================== */
.rights-grid {
  display: grid;
  gap: var(--space-4);
  margin-block: var(--space-6);
}

@media (min-width: 48rem) {
  .rights-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-5);
  }
}

.right-card {
  background-color: var(--color-warning-light);
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  border-inline-start: 4px solid var(--color-warning);
  transition: all var(--transition-base);
}

.right-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.right-card h4 {
  color: var(--color-gray-900);
  margin-block: 0 var(--space-3);
  font-size: var(--font-size-lg);
}

.right-card p {
  color: var(--color-gray-700);
  margin-block-end: var(--space-2);
}

.right-card p:last-child {
  margin-block-end: 0;
}

.right-card ul {
  margin-inline-start: var(--space-5);
  margin-block-end: 0;
}

.right-card li {
  color: var(--color-gray-700);
}

/* ===================================
   Contact Card
   =================================== */
.contact-card {
  background-color: var(--color-info-light);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  margin-block: var(--space-6);
  border: 2px solid var(--color-info);
}

.contact-card dl {
  display: grid;
  gap: var(--space-4);
}

.contact-card dt {
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
  font-size: var(--font-size-base);
}

.contact-card dd {
  margin-inline-start: 0;
  color: var(--color-text-primary);
  font-size: var(--font-size-base);
}

/* ===================================
   Links
   =================================== */
a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-hover);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

a:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

a:active {
  color: var(--color-primary-dark);
}

/* External link indicator */
a[target="_blank"]::after {
  content: " ↗";
  font-size: 0.85em;
  vertical-align: super;
  margin-inline-start: var(--space-1);
}

/* ===================================
   Footer
   =================================== */
.page-footer {
  margin-block-start: var(--space-16);
  padding-block: var(--space-10);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-white);
  text-align: center;
  margin-inline: calc(-1 * var(--space-4));
  margin-block-end: 0;
}

@media (min-width: 48rem) {
  .page-footer {
    margin-inline: calc(-1 * var(--space-6));
  }
}

.footer-content {
  max-width: var(--container-max-width);
  margin-inline: auto;
}

.copyright {
  margin-block-end: var(--space-4);
  font-size: var(--font-size-sm);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-4);
  margin: 0;
  padding: 0;
}

.footer-links li {
  margin: 0;
}

.footer-links a {
  color: var(--color-white);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  transition: opacity var(--transition-fast);
}

.footer-links a:hover {
  opacity: 0.8;
  text-decoration: underline;
}

.footer-links a:focus {
  outline-color: var(--color-white);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 47.9375rem) {
  .subsection {
    margin-inline-start: var(--space-4);
    padding-inline-start: var(--space-3);
  }

  .service-card,
  .right-card {
    padding: var(--space-4);
  }
}

/* ===================================
   Print Styles
   =================================== */
@media print {
  :root {
    --color-background: white;
    --color-text-primary: black;
    --color-text-secondary: #333;
  }

  body {
    background-color: white;
    color: black;
  }

  .container {
    box-shadow: none;
    max-width: 100%;
  }

  .page-header,
  .page-footer {
    background: white;
    color: black;
    border: 2px solid black;
  }

  a {
    color: black;
    text-decoration: underline;
  }

  .skip-link {
    display: none;
  }

  section,
  article {
    page-break-inside: avoid;
  }

  h2,
  h3,
  h4 {
    page-break-after: avoid;
  }
}

/* ===================================
   Accessibility - Reduced Motion
   =================================== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ===================================
   Dark Mode Support
   =================================== */
@media (prefers-color-scheme: dark) {
  :root {
    --color-text-primary: var(--color-gray-100);
    --color-text-secondary: var(--color-gray-300);
    --color-text-muted: var(--color-gray-400);
    --color-background: var(--color-gray-900);
    --color-background-alt: var(--color-gray-800);
    --color-border: var(--color-gray-700);
  }

  body {
    background-color: var(--color-gray-900);
  }

  .container {
    background-color: var(--color-gray-900);
  }

  .intro {
    background-color: rgb(59 130 246 / 0.15);
    border-inline-start-color: var(--color-info);
  }

  .table-of-contents {
    background-color: var(--color-gray-800);
    border-color: var(--color-gray-700);
  }

  .table-of-contents li:hover {
    background-color: var(--color-gray-700);
  }

  .service-card {
    background-color: var(--color-gray-800);
    border-color: var(--color-gray-700);
  }

  .service-card:hover {
    border-color: var(--color-primary);
  }

  .right-card {
    background-color: rgb(245 158 11 / 0.15);
    border-inline-start-color: var(--color-warning);
  }

  .right-card h4,
  .right-card p,
  .right-card li {
    color: var(--color-gray-100);
  }

  .contact-card {
    background-color: rgb(59 130 246 / 0.15);
    border-color: var(--color-info);
  }

  .contact-card dd {
    color: var(--color-gray-100);
  }

  .callout-info {
    background-color: rgb(59 130 246 / 0.15);
    color: var(--color-gray-100);
  }

  .callout-success {
    background-color: rgb(16 185 129 / 0.15);
    color: var(--color-gray-100);
  }

  a {
    color: var(--color-primary-light);
  }

  a:hover {
    color: var(--color-primary-light);
  }
}

/* ===================================
   High Contrast Mode
   =================================== */
@media (prefers-contrast: high) {
  :root {
    --color-primary: #0000ff;
    --color-border: #000000;
  }

  a {
    text-decoration: underline;
  }

  .service-card,
  .right-card,
  .contact-card,
  .intro,
  .table-of-contents {
    border-width: 2px;
    border-color: currentColor;
  }
}