/* ============================================================
   eMonitor Design System — Shared Styles
   Semantic, accessible, performance-optimized
   ============================================================ */

/* --- CSS Custom Properties (Design Tokens) --- */
:root {
  /* Brand Colors */
  --color-primary: #5470CB;
  --color-primary-dark: #3859C2;
  --color-primary-light: #E4EBF8;
  --color-primary-surface: #F6FAFF;

  /* Neutral Colors */
  --color-text: #33475B;
  --color-text-light: #536171;
  --color-text-muted: #7E8EA0;
  --color-heading: #1F2D3D;
  --color-white: #FFFFFF;
  --color-bg: #FFFFFF;
  --color-border: #E1E8F0;

  /* Accent Colors */
  --color-success: #2ECC71;
  --color-warning: #F39C12;
  --color-danger: #E74C3C;
  --color-info: #3498DB;
  --color-purple: #7B61FF;
  --color-purple-light: #F6F4FF;

  /* Typography */
  --font-family: "source-sans-pro", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-size-base: 1rem;
  --font-size-sm: 0.875rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --line-height-base: 1.7;
  --line-height-heading: 1.25;

  /* Spacing Scale */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 800px;
  --container-wide: 1400px;
  --header-height: 72px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

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

html {
  font-size: 100%;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  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-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- 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: var(--color-white);
  border-radius: var(--radius-sm);
  z-index: 100000;
  font-weight: 600;
  text-decoration: none;
}
.skip-link:focus {
  top: var(--space-md);
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family);
  color: var(--color-heading);
  line-height: var(--line-height-heading);
  font-weight: 700;
}

h1 { font-size: clamp(2rem, 4vw, 3rem); margin-bottom: var(--space-lg); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); margin-bottom: var(--space-md); }
h3 { font-size: clamp(1.25rem, 2.5vw, 1.75rem); margin-bottom: var(--space-md); }
h4 { font-size: clamp(1.1rem, 2vw, 1.375rem); margin-bottom: var(--space-sm); }
h5 { font-size: 1.125rem; margin-bottom: var(--space-sm); }
h6 { font-size: 1rem; margin-bottom: var(--space-sm); }

p { margin-bottom: var(--space-md); max-width: 75ch; }

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--color-primary-dark); }
a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

ul, ol {
  padding-left: var(--space-xl);
  margin-bottom: var(--space-md);
}
li { margin-bottom: var(--space-xs); }

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

/* --- Layout Containers --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}
.container--narrow { max-width: var(--container-narrow); }
.container--wide { max-width: var(--container-wide); }

/* --- Section Spacing --- */
.section {
  padding: var(--space-4xl) 0;
}
.section--sm { padding: var(--space-2xl) 0; }
.section--lg { padding: calc(var(--space-4xl) * 1.5) 0; }
.section--surface { background-color: var(--color-primary-surface); }
.section--dark {
  background-color: var(--color-heading);
  color: var(--color-white);
}
.section--dark h1, .section--dark h2, .section--dark h3,
.section--dark h4, .section--dark h5, .section--dark h6 {
  color: var(--color-white);
}

/* --- Site Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-white);
  box-shadow: var(--shadow-sm);
  height: var(--header-height);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.site-header__logo img {
  height: 40px;
  width: auto;
}

/* Primary Navigation */
.primary-nav { display: flex; align-items: center; gap: var(--space-xl); }
.primary-nav__list {
  display: flex;
  list-style: none;
  gap: var(--space-lg);
  padding: 0;
  margin: 0;
}
.primary-nav__link {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text);
  padding: var(--space-sm) 0;
  position: relative;
}
.primary-nav__link:hover,
.primary-nav__link[aria-current="page"] {
  color: var(--color-primary);
}
.primary-nav__link[aria-current="page"]::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0; right: 0;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
}
.primary-nav__actions { display: flex; gap: var(--space-md); align-items: center; }

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: var(--space-sm);
  cursor: pointer;
}
.nav-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
  transition: var(--transition-base);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: 600;
  padding: 0.625rem 1.75rem;
  border-radius: var(--radius-md);
  border: 2px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-base);
  white-space: nowrap;
}
.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn--primary {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}
.btn--primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: var(--color-white);
}

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

.btn--ghost {
  background: transparent;
  color: var(--color-text);
  border-color: transparent;
}
.btn--ghost:hover { color: var(--color-primary); }

.btn--lg { padding: 0.875rem 2.25rem; font-size: var(--font-size-lg); }
.btn--sm { padding: 0.375rem 1.25rem; font-size: var(--font-size-sm); }

/* --- Hero Section --- */
.hero {
  padding: var(--space-4xl) 0;
  position: relative;
  overflow: hidden;
}
.hero__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}
.hero__eyebrow {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--space-md);
}
.hero__title { max-width: 600px; }
.hero__description {
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  max-width: 540px;
  margin-bottom: var(--space-xl);
}
.hero__actions { display: flex; gap: var(--space-md); flex-wrap: wrap; align-items: center; }
.hero__micro-copy {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-sm);
}
.hero__image img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
}

/* --- Social Proof Bar --- */
.social-proof {
  display: flex;
  align-items: center;
  gap: var(--space-2xl);
  flex-wrap: wrap;
  padding: var(--space-xl) 0;
}
.social-proof__item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}
.social-proof__logo { height: 28px; width: auto; }
.social-proof__rating { font-weight: 700; color: var(--color-heading); }
.social-proof__count { font-size: var(--font-size-sm); color: var(--color-text-muted); }

/* --- Feature Cards Grid --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
}
.feature-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: all var(--transition-base);
  text-decoration: none;
  color: inherit;
  display: block;
}
.feature-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
  transform: translateY(-2px);
  color: inherit;
}
.feature-card__icon {
  width: 48px;
  height: 48px;
  margin-bottom: var(--space-md);
}
.feature-card__title {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-sm);
}
.feature-card__description {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-md);
}
.feature-card__link {
  font-weight: 600;
  font-size: var(--font-size-sm);
}

/* --- Feature Detail Section (alternating image+text) --- */
.feature-detail {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}
.feature-detail--reverse { direction: rtl; }
.feature-detail--reverse > * { direction: ltr; }
.feature-detail__image img {
  width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}
.feature-detail__content h2 { color: var(--color-heading); }
.feature-detail__list {
  list-style: none;
  padding: 0;
}
.feature-detail__list li {
  position: relative;
  padding-left: var(--space-xl);
  margin-bottom: var(--space-md);
  line-height: 1.6;
}
.feature-detail__list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
}

/* --- Comparison Table --- */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.comparison-table thead {
  background: var(--color-primary);
  color: var(--color-white);
}
.comparison-table th,
.comparison-table td {
  padding: var(--space-md) var(--space-lg);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}
.comparison-table th { font-weight: 600; }
.comparison-table tbody tr:hover { background: var(--color-primary-surface); }
.comparison-table .check { color: var(--color-success); font-weight: 700; }
.comparison-table .cross { color: var(--color-danger); font-weight: 700; }

/* --- Testimonial Cards --- */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-xl);
}
.testimonial-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
}
.testimonial-card__stars {
  color: #F5A623;
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-md);
}
.testimonial-card__quote {
  font-style: italic;
  margin-bottom: var(--space-lg);
  line-height: 1.8;
}
.testimonial-card__author {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}
.testimonial-card__name { font-weight: 700; }
.testimonial-card__role { font-size: var(--font-size-sm); color: var(--color-text-muted); }

/* --- FAQ Section --- */
.faq-list {
  max-width: var(--container-narrow);
  margin: 0 auto;
}
.faq-item {
  border-bottom: 1px solid var(--color-border);
}
.faq-item summary {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-heading);
  padding: var(--space-lg) 0;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq-item summary::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--color-primary);
  transition: transform var(--transition-base);
}
.faq-item[open] summary::after {
  content: '−';
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item__answer {
  padding: 0 0 var(--space-lg);
  line-height: 1.8;
  color: var(--color-text-light);
}

/* --- CTA Banner --- */
.cta-banner {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-white);
  text-align: center;
  padding: var(--space-4xl) var(--space-xl);
  border-radius: var(--radius-xl);
}
.cta-banner h2 { color: var(--color-white); margin-bottom: var(--space-md); }
.cta-banner p { color: rgba(255,255,255,0.9); margin: 0 auto var(--space-xl); }
.cta-banner .btn--primary {
  background: var(--color-white);
  color: var(--color-primary);
  border-color: var(--color-white);
}
.cta-banner .btn--primary:hover {
  background: rgba(255,255,255,0.9);
}

/* --- Breadcrumbs --- */
.breadcrumbs {
  padding: var(--space-md) 0;
  font-size: var(--font-size-sm);
}
.breadcrumbs__list {
  display: flex;
  list-style: none;
  padding: 0;
  margin: 0;
  gap: var(--space-sm);
}
.breadcrumbs__item::after { content: '/'; color: var(--color-text-muted); margin-left: var(--space-sm); }
.breadcrumbs__item:last-child::after { display: none; }
.breadcrumbs__link { color: var(--color-text-muted); }
.breadcrumbs__link:hover { color: var(--color-primary); }
.breadcrumbs__current { color: var(--color-text); font-weight: 600; }

/* --- Page Header (for inner pages) --- */
.page-header {
  background: var(--color-primary-surface);
  padding: var(--space-3xl) 0;
  text-align: center;
}
.page-header__eyebrow {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--space-sm);
}
.page-header__description {
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  max-width: 640px;
  margin: 0 auto;
}

/* --- Site Footer --- */
.site-footer {
  background: var(--color-heading);
  color: rgba(255,255,255,0.8);
  padding: var(--space-4xl) 0 var(--space-xl);
}
.site-footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-3xl);
  margin-bottom: var(--space-3xl);
}
.site-footer__brand p { max-width: 300px; }
.site-footer__heading {
  color: var(--color-white);
  font-size: var(--font-size-base);
  font-weight: 700;
  margin-bottom: var(--space-lg);
}
.site-footer__links {
  list-style: none;
  padding: 0;
}
.site-footer__links li { margin-bottom: var(--space-sm); }
.site-footer__links a {
  color: rgba(255,255,255,0.7);
  font-size: var(--font-size-sm);
}
.site-footer__links a:hover { color: var(--color-white); }
.site-footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.15);
  padding-top: var(--space-xl);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--font-size-sm);
}

/* --- Pricing Cards --- */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-xl);
  align-items: start;
}
.pricing-card {
  background: var(--color-white);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  text-align: center;
}
.pricing-card--featured {
  border-color: var(--color-primary);
  position: relative;
}
.pricing-card--featured::before {
  content: 'Most Popular';
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--space-xs) var(--space-lg);
  border-radius: 20px;
  font-size: var(--font-size-sm);
  font-weight: 600;
}
.pricing-card__name { font-size: var(--font-size-xl); font-weight: 700; margin-bottom: var(--space-sm); }
.pricing-card__price {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-heading);
  margin-bottom: var(--space-xs);
}
.pricing-card__price span { font-size: var(--font-size-base); font-weight: 400; color: var(--color-text-muted); }
.pricing-card__features {
  list-style: none;
  padding: 0;
  margin: var(--space-xl) 0;
  text-align: left;
}
.pricing-card__features li {
  padding: var(--space-sm) 0;
  padding-left: var(--space-xl);
  position: relative;
  border-bottom: 1px solid var(--color-border);
}
.pricing-card__features li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-success);
  font-weight: 700;
}

/* --- Responsive Grid Utilities --- */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-xl); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-xl); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-xl); }

/* --- Text Utilities --- */
.text-center { text-align: center; }
.text-primary { color: var(--color-primary); }
.text-muted { color: var(--color-text-muted); }
.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;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .hero__grid { grid-template-columns: 1fr; text-align: center; }
  .hero__title, .hero__description { max-width: 100%; margin-left: auto; margin-right: auto; }
  .hero__actions { justify-content: center; }
  .hero__image { order: -1; max-width: 600px; margin: 0 auto; }
  .feature-detail { grid-template-columns: 1fr; }
  .feature-detail--reverse { direction: ltr; }
  .site-footer__grid { grid-template-columns: 1fr 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .primary-nav__list { display: none; }
  .nav-toggle { display: block; }
  .primary-nav__list--open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: var(--header-height);
    left: 0; right: 0;
    background: var(--color-white);
    box-shadow: var(--shadow-lg);
    padding: var(--space-lg);
    z-index: 999;
  }
  .social-proof { justify-content: center; gap: var(--space-lg); }
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .site-footer__grid { grid-template-columns: 1fr; }
  .site-footer__bottom { flex-direction: column; gap: var(--space-md); text-align: center; }
  .container { padding: 0 var(--space-md); }
  .section { padding: var(--space-2xl) 0; }
}

@media (max-width: 480px) {
  .hero__actions { flex-direction: column; }
  .btn--lg { width: 100%; }
  .features-grid { grid-template-columns: 1fr; }
  .pricing-grid { grid-template-columns: 1fr; }
}