/* ==========================================================================
   Syntaxis Marketing Site - Styles
   WCAG 2.1 AA Compliant
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Custom Properties (Design Tokens)
   -------------------------------------------------------------------------- */
:root {
  /* Colors - Light Mode */
  --color-primary: #1a73e8;
  --color-primary-hover: #1557b0;
  --color-primary-light: #4285f4;
  --color-text: #202124;
  --color-text-secondary: #5f6368;
  --color-background: #ffffff;
  --color-surface: #f8f9fa;
  --color-border: #dadce0;
  --color-success: #34a853;
  --color-error: #ea4335;
  
  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-size-base: 1rem;
  --font-size-sm: 0.875rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --line-height-base: 1.6;
  --line-height-tight: 1.3;
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  
  /* Layout */
  --max-width: 1200px;
  --max-width-narrow: 800px;
  --border-radius: 8px;
  --border-radius-lg: 12px;
  
  /* Focus ring - 3:1 contrast required */
  --focus-ring: 0 0 0 3px rgba(26, 115, 232, 0.4);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: #8ab4f8;
    --color-primary-hover: #aecbfa;
    --color-primary-light: #669df6;
    --color-text: #e8eaed;
    --color-text-secondary: #9aa0a6;
    --color-background: #1f1f1f;
    --color-surface: #292929;
    --color-border: #3c4043;
    --focus-ring: 0 0 0 3px rgba(138, 180, 248, 0.4);
  }
}

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

/* --------------------------------------------------------------------------
   Reset & Base
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 100%; /* Respect user's browser font size */
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--color-text);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* --------------------------------------------------------------------------
   Typography
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-md);
  line-height: var(--line-height-tight);
  font-weight: 600;
}

h1 {
  font-size: var(--font-size-4xl);
}

h2 {
  font-size: var(--font-size-3xl);
}

h3 {
  font-size: var(--font-size-xl);
}

p {
  margin: 0 0 var(--space-md);
}

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

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

a:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
  border-radius: 2px;
}

ul, ol {
  margin: 0 0 var(--space-md);
  padding-left: var(--space-lg);
}

li {
  margin-bottom: var(--space-sm);
}

/* --------------------------------------------------------------------------
   Skip Link (Accessibility)
   -------------------------------------------------------------------------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-primary);
  color: #fff;
  text-decoration: none;
  border-radius: var(--border-radius);
  z-index: 1000;
}

.skip-link:focus {
  top: var(--space-md);
  outline: none;
  box-shadow: var(--focus-ring);
}

/* 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: 0;
}

/* --------------------------------------------------------------------------
   Header & Navigation
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  background: var(--color-background);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

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

.logo {
  text-decoration: none;
  color: var(--color-text);
}

.logo-text {
  font-size: var(--font-size-xl);
  font-weight: 700;
}

.nav-links {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--font-size-sm);
  padding: var(--space-sm);
  border-radius: var(--border-radius);
}

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

.nav-links a:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.nav-links a[aria-current="page"] {
  color: var(--color-primary);
  font-weight: 500;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  padding: var(--space-sm) var(--space-md);
  background: var(--color-primary);
  color: #fff !important;
  text-decoration: none;
  border-radius: var(--border-radius);
  font-size: var(--font-size-sm);
  font-weight: 500;
  min-height: 44px; /* Touch target */
  min-width: 44px;
}

.nav-cta:hover {
  background: var(--color-primary-hover);
}

.nav-cta:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

/* Mobile Navigation */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .nav-container {
    padding: var(--space-md);
  }
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-md) var(--space-xl);
  font-size: var(--font-size-base);
  font-weight: 500;
  text-decoration: none;
  border-radius: var(--border-radius);
  border: 2px solid transparent;
  cursor: pointer;
  transition: background-color var(--transition-fast), 
              border-color var(--transition-fast),
              transform var(--transition-fast);
  min-height: 48px; /* Touch target */
  min-width: 44px;
}

.btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  color: #fff;
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-surface);
  color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
}

.btn-large {
  padding: var(--space-lg) var(--space-2xl);
  font-size: var(--font-size-lg);
}

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-3xl) var(--space-lg);
}

.hero-content {
  max-width: 540px;
}

.hero h1 {
  font-size: clamp(var(--font-size-3xl), 5vw, var(--font-size-4xl));
  margin-bottom: var(--space-lg);
}

.hero-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.hero-price {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-xl);
}

.hero-price strong {
  color: var(--color-primary);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.hero-illustration {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-illustration img {
  max-width: 100%;
  height: auto;
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    padding: var(--space-2xl) var(--space-lg);
  }
  
  .hero-content {
    max-width: none;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .hero-illustration {
    order: -1;
  }
  
  .hero-illustration img {
    max-width: 300px;
  }
}

/* --------------------------------------------------------------------------
   Features Section
   -------------------------------------------------------------------------- */
.features {
  background: var(--color-surface);
  padding: var(--space-3xl) var(--space-lg);
}

.features h2 {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-xl);
  max-width: var(--max-width);
  margin: 0 auto;
}

.feature-card {
  background: var(--color-background);
  padding: var(--space-xl);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
}

.feature-icon {
  margin-bottom: var(--space-md);
}

.feature-icon img {
  width: 48px;
  height: 48px;
}

.feature-card h3 {
  margin-bottom: var(--space-sm);
}

.feature-card p {
  color: var(--color-text-secondary);
  margin: 0;
}

/* --------------------------------------------------------------------------
   How It Works Section
   -------------------------------------------------------------------------- */
.how-it-works {
  padding: var(--space-3xl) var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
}

.how-it-works h2 {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.diagram-container {
  margin: 0;
}

.how-diagram {
  width: 100%;
  max-width: 900px;
  margin: 0 auto var(--space-md);
}

.diagram-container figcaption {
  text-align: center;
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

/* --------------------------------------------------------------------------
   Requirements Section
   -------------------------------------------------------------------------- */
.requirements {
  background: var(--color-surface);
  padding: var(--space-3xl) var(--space-lg);
}

.requirements h2 {
  text-align: center;
  margin-bottom: var(--space-md);
}

.requirements-intro {
  text-align: center;
  color: var(--color-text-secondary);
  max-width: var(--max-width-narrow);
  margin: 0 auto var(--space-2xl);
}

.requirements-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
  max-width: var(--max-width);
  margin: 0 auto;
}

.requirement-card {
  background: var(--color-background);
  padding: var(--space-xl);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
}

.requirement-card h3 {
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-lg);
}

.requirement-card p {
  color: var(--color-text-secondary);
  margin: 0;
}

/* --------------------------------------------------------------------------
   Pricing Section
   -------------------------------------------------------------------------- */
.pricing {
  padding: var(--space-3xl) var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
}

.pricing h2 {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.pricing-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
  max-width: 700px;
  margin: 0 auto var(--space-2xl);
}

.pricing-card {
  position: relative;
  background: var(--color-surface);
  padding: var(--space-xl);
  border-radius: var(--border-radius-lg);
  border: 2px solid var(--color-border);
  text-align: center;
}

.pricing-featured {
  border-color: var(--color-primary);
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-xs) var(--space-md);
  border-radius: 20px;
  font-size: var(--font-size-sm);
  font-weight: 500;
}

.pricing-card h3 {
  margin-bottom: var(--space-md);
}

.pricing-amount {
  margin-bottom: var(--space-md);
}

.pricing-amount .price {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  color: var(--color-text);
}

.pricing-amount .price-term {
  display: block;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.pricing-description {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.pricing-card .btn {
  width: 100%;
}

.pricing-features {
  text-align: center;
  max-width: 500px;
  margin: 0 auto;
}

.pricing-features ul {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-sm);
}

.pricing-features li {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.pricing-features li::before {
  content: "✓ ";
  color: var(--color-success);
}

/* --------------------------------------------------------------------------
   Final CTA Section
   -------------------------------------------------------------------------- */
.final-cta {
  background: var(--color-surface);
  padding: var(--space-3xl) var(--space-lg);
  text-align: center;
}

.final-cta h2 {
  margin-bottom: var(--space-sm);
}

.final-cta p {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-xl);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-2xl) var(--space-lg);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  max-width: var(--max-width);
  margin: 0 auto var(--space-lg);
}

.footer-brand p {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  margin-top: var(--space-xs);
}

.footer-nav ul {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-nav a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

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

.footer-tagline {
  text-align: center;
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  margin: 0;
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
  max-width: var(--max-width);
  margin: 0 auto;
}

@media (max-width: 600px) {
  .footer-content {
    flex-direction: column;
    gap: var(--space-lg);
  }
  
  .footer-nav ul {
    flex-direction: column;
    gap: var(--space-sm);
  }
}

/* --------------------------------------------------------------------------
   Privacy Page
   -------------------------------------------------------------------------- */
.privacy-page {
  padding: var(--space-2xl) var(--space-lg);
}

.privacy-content {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
}

.privacy-header {
  margin-bottom: var(--space-2xl);
}

.privacy-header h1 {
  margin-bottom: var(--space-sm);
}

.last-updated {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.privacy-intro {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-2xl);
}

.privacy-content section {
  margin-bottom: var(--space-2xl);
}

.privacy-content h2 {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-md);
  padding-top: var(--space-md);
}

.privacy-content h3 {
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
}

.highlight-list {
  background: var(--color-surface);
  padding: var(--space-lg) var(--space-xl);
  border-radius: var(--border-radius);
  border-left: 4px solid var(--color-primary);
}

.highlight-list li {
  margin-bottom: var(--space-sm);
}

.highlight-list li:last-child {
  margin-bottom: 0;
}

.privacy-summary {
  background: var(--color-surface);
  padding: var(--space-xl);
  border-radius: var(--border-radius-lg);
}

.privacy-summary p {
  margin: 0;
  font-size: var(--font-size-lg);
}

/* --------------------------------------------------------------------------
   Focus States - Enhanced for Accessibility
   -------------------------------------------------------------------------- */
:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}