/* ===================================
   CSS Design System - a-ask.io
   =================================== */

/* CSS Custom Properties */
:root {
  /* Brand Colors */
  --color-primary: #1E40AF;
  --color-accent: #F97316;
  
  /* Neutral Colors */
  --color-charcoal: #1e293b;
  --color-gray: #64748b;
  --color-light-gray: #f8fafc;
  --color-white: #ffffff;
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #1E40AF 0%, #7C3AED 100%);
  --gradient-accent: linear-gradient(135deg, #F97316 0%, #EC4899 100%);
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  
  /* Font Sizes */
  --font-size-h1: 3rem;
  --font-size-h2: 2.25rem;
  --font-size-h3: 1.75rem;
  --font-size-h4: 1.5rem;
  --font-size-large: 1.125rem;
  --font-size-base: 1rem;
  --font-size-small: 0.875rem;
  
  /* Font Weights */
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  /* Line Heights */
  --line-height-tight: 1.2;
  --line-height-normal: 1.6;
  --line-height-relaxed: 1.8;
  
  /* 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;
  --space-4xl: 6rem;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;
  --transition-slow: 500ms ease;
  
  /* Breakpoints (for reference) */
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
}

/* ===================================
   Reset & Base Styles
   =================================== */

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-normal);
  color: var(--color-charcoal);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===================================
   Typography
   =================================== */

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  margin-bottom: var(--space-lg);
  color: var(--color-charcoal);
}

h1 { font-size: var(--font-size-h1); }
h2 { font-size: var(--font-size-h2); }
h3 { font-size: var(--font-size-h3); }
h4 { font-size: var(--font-size-h4); }

p {
  margin-bottom: var(--space-md);
  line-height: var(--line-height-relaxed);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-base);
}

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

a:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

ul {
  list-style: none;
}

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

/* ===================================
   Layout
   =================================== */

.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

@media (min-width: 640px) {
  .container {
    padding: 0 var(--space-xl);
  }
}

/* ===================================
   Skip Link (Accessibility)
   =================================== */

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary);
  color: white;
  padding: var(--space-sm) var(--space-md);
  text-decoration: none;
  z-index: 100;
}

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

/* ===================================
   Header / Navigation
   =================================== */

.site-header {
  position: sticky;
  top: 0;
  background: var(--color-white);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  z-index: 50;
  transition: box-shadow var(--transition-base);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-md);
  padding-bottom: var(--space-md);
}

.logo img {
  height: 40px;
  width: auto;
}

.main-nav ul {
  display: none;
  gap: var(--space-xl);
}

@media (min-width: 768px) {
  .main-nav ul {
    display: flex;
  }
}

.nav-link {
  font-weight: var(--font-weight-semibold);
  color: var(--color-charcoal);
  padding: var(--space-sm) 0;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.mobile-menu-toggle {
  display: block;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
}

@media (min-width: 768px) {
  .mobile-menu-toggle {
    display: none;
  }
}

.hamburger {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-charcoal);
  position: relative;
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  width: 24px;
  height: 2px;
  background: var(--color-charcoal);
  transition: transform var(--transition-base);
}

.hamburger::before {
  top: -8px;
}

.hamburger::after {
  top: 8px;
}

/* ===================================
   Hero Section
   =================================== */

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-primary);
  color: var(--color-white);
  position: relative;
  overflow: hidden;
  padding: var(--space-4xl) 0;
}

.hero-content {
  text-align: center;
  z-index: 2;
  position: relative;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--space-lg);
  color: var(--color-white);
  animation: fadeInUp 0.8s ease;
}

@media (min-width: 768px) {
  .hero-title {
    font-size: var(--font-size-h1);
  }
}

.hero-subtitle {
  font-size: var(--font-size-large);
  margin-bottom: var(--space-2xl);
  opacity: 0.95;
  animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-cta {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-visual {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0.1;
  z-index: 1;
}

/* ===================================
   Buttons
   =================================== */

.btn {
  display: inline-block;
  padding: var(--space-md) var(--space-xl);
  border-radius: 8px;
  font-weight: var(--font-weight-semibold);
  font-size: var(--font-size-base);
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
  text-align: center;
  min-width: 140px;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(255, 255, 255, 0.3);
}

.btn-secondary {
  background: transparent;
  color: var(--color-white);
  border: 2px solid var(--color-white);
}

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

/* ===================================
   About Section
   =================================== */

.about {
  padding: var(--space-4xl) 0;
  background: var(--color-light-gray);
}

.section-title {
  text-align: center;
  margin-bottom: var(--space-xl);
  color: var(--color-charcoal);
}

.section-subtitle {
  text-align: center;
  font-size: var(--font-size-large);
  color: var(--color-gray);
  margin-bottom: var(--space-3xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.about-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}

@media (min-width: 768px) {
  .about-content {
    grid-template-columns: repeat(3, 1fr);
  }
}

.about-card {
  background: var(--color-white);
  padding: var(--space-2xl);
  border-radius: 12px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.about-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
}

.about-card h3 {
  color: var(--color-primary);
  margin-bottom: var(--space-md);
}

.values-list li {
  padding: var(--space-sm) 0;
  padding-left: var(--space-lg);
  position: relative;
}

.values-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: var(--font-weight-bold);
}

/* ===================================
   Business Divisions Section
   =================================== */

.divisions {
  padding: var(--space-4xl) 0;
  background: var(--color-white);
}

.division-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2xl);
}

@media (min-width: 768px) {
  .division-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.division-card {
  background: var(--color-white);
  padding: var(--space-2xl);
  border-radius: 12px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
  border-top: 4px solid var(--color-primary);
}

.division-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.2);
}

.division-card.govtech {
  border-top-color: #1E40AF;
}

.division-card.commercial {
  border-top-color: #F97316;
}

.division-card.services {
  border-top-color: #7C3AED;
}

.division-icon {
  font-size: 3rem;
  margin-bottom: var(--space-md);
}

.division-card h3 {
  color: var(--color-charcoal);
  margin-bottom: var(--space-md);
}

.division-description {
  color: var(--color-gray);
  margin-bottom: var(--space-lg);
}

.features-list li {
  padding: var(--space-sm) 0;
  padding-left: var(--space-lg);
  position: relative;
  color: var(--color-charcoal);
}

.features-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: var(--font-weight-bold);
}

/* ===================================
   Credibility Section
   =================================== */

.credibility {
  padding: var(--space-4xl) 0;
  background: var(--color-light-gray);
}

.tech-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}

@media (min-width: 640px) {
  .tech-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .tech-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.tech-item {
  text-align: center;
  padding: var(--space-xl);
  background: var(--color-white);
  border-radius: 12px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.tech-badge {
  display: inline-block;
  padding: var(--space-md) var(--space-lg);
  background: var(--gradient-primary);
  color: var(--color-white);
  border-radius: 8px;
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-md);
}

.tech-item p {
  color: var(--color-gray);
  font-size: var(--font-size-small);
  margin: 0;
}

/* ===================================
   Footer
   =================================== */

.site-footer {
  background: var(--color-charcoal);
  color: var(--color-white);
  padding: var(--space-3xl) 0 var(--space-xl) 0;
}

.footer-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
  align-items: center;
  text-align: center;
}

@media (min-width: 768px) {
  .footer-content {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.footer-brand img {
  margin-bottom: var(--space-md);
}

.footer-tagline {
  color: var(--color-gray);
  font-size: var(--font-size-small);
}

.copyright {
  color: var(--color-gray);
  font-size: var(--font-size-small);
  margin-bottom: var(--space-sm);
}

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

.footer-nav a {
  color: var(--color-white);
  font-size: var(--font-size-small);
}

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

/* ===================================
   Back to Top Button
   =================================== */

.back-to-top {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: var(--color-white);
  border: none;
  border-radius: 50%;
  font-size: 1.5rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base), transform var(--transition-base);
  z-index: 40;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-4px);
  background: var(--color-accent);
}

/* ===================================
   Animations
   =================================== */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* ===================================
   Utility Classes
   =================================== */

.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;
}

/* ===================================
   Responsive Typography
   =================================== */

@media (max-width: 767px) {
  :root {
    --font-size-h1: 2rem;
    --font-size-h2: 1.75rem;
    --font-size-h3: 1.5rem;
    --font-size-h4: 1.25rem;
  }
}