/* ============================================
   TWILIO SERVICE CENTER - BASE DESIGN SYSTEM
   ============================================ */

/* Import Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* ============================================
   CSS CUSTOM PROPERTIES (DESIGN TOKENS)
   ============================================ */
:root {
  /* Color Palette - Dark Theme with Vibrant Accents */
  --color-bg-primary: #0a0e1a;
  --color-bg-secondary: #131824;
  --color-bg-tertiary: #1a2030;
  --color-bg-glass: rgba(26, 32, 48, 0.7);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --gradient-success: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
  --gradient-warning: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
  
  /* Text Colors */
  --color-text-primary: #ffffff;
  --color-text-secondary: #b4b9c8;
  --color-text-muted: #6b7280;
  
  /* Accent Colors */
  --color-accent-primary: #667eea;
  --color-accent-secondary: #764ba2;
  --color-accent-cyan: #00f2fe;
  --color-success: #43e97b;
  --color-warning: #fee140;
  --color-error: #f5576c;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* Border Radius */
  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
  --radius-xl: 2rem;
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 20px rgba(102, 126, 234, 0.4);
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3rem;
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 400ms ease-in-out;
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  font-size: var(--font-size-base);
  overflow-x: hidden;
}

/* Animated Background */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(118, 75, 162, 0.1) 0%, transparent 50%);
  z-index: -1;
  animation: backgroundPulse 15s ease-in-out infinite;
}

@keyframes backgroundPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

p {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-secondary);
}

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

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

/* ============================================
   LAYOUT COMPONENTS
   ============================================ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.container-wide {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section {
  padding: var(--spacing-2xl) 0;
}

/* ============================================
   NAVIGATION BAR
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--color-bg-glass);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding: var(--spacing-sm) 0;
  transition: all var(--transition-base);
}

.navbar.scrolled {
  box-shadow: var(--shadow-lg);
  background: rgba(26, 32, 48, 0.95);
}

.navbar-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.navbar-brand {
  font-size: var(--font-size-xl);
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: transform var(--transition-fast);
}

.navbar-brand:hover {
  transform: scale(1.05);
}

.navbar-menu {
  display: flex;
  gap: var(--spacing-lg);
  list-style: none;
  align-items: center;
}

.navbar-link {
  color: var(--color-text-secondary);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  position: relative;
}

.navbar-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: all var(--transition-base);
  transform: translateX(-50%);
}

.navbar-link:hover {
  color: var(--color-text-primary);
}

.navbar-link:hover::after {
  width: 80%;
}

.navbar-link.active {
  color: var(--color-text-primary);
  background: rgba(102, 126, 234, 0.1);
}

/* Mobile Menu Toggle */
.navbar-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-text-primary);
  font-size: var(--font-size-2xl);
  cursor: pointer;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-base);
  font-weight: 600;
  text-align: center;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  transform: translate(-50%, -50%);
  transition: width var(--transition-slow), height var(--transition-slow);
}

.btn:hover::before {
  width: 300px;
  height: 300px;
}

.btn-primary {
  background: var(--gradient-primary);
  color: var(--color-text-primary);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

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

.btn-secondary:hover {
  background: var(--color-accent-primary);
  box-shadow: var(--shadow-md);
}

.btn-success {
  background: var(--gradient-success);
  color: var(--color-bg-primary);
}

.btn-lg {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-lg);
}

.btn-sm {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: var(--font-size-sm);
}

/* ============================================
   CARDS
   ============================================ */
.card {
  background: var(--color-bg-glass);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(102, 126, 234, 0.3);
}

.card-header {
  margin-bottom: var(--spacing-md);
}

.card-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.card-subtitle {
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

.card-body {
  margin-bottom: var(--spacing-md);
}

.card-footer {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--spacing-md);
  margin-top: var(--spacing-md);
}

/* Glass Card Variant */
.card-glass {
  background: rgba(26, 32, 48, 0.5);
  backdrop-filter: blur(30px);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

/* ============================================
   GRID SYSTEM
   ============================================ */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-center { text-align: center; }
.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

/* ============================================
   FOOTER
   ============================================ */
.footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: var(--spacing-xl) 0 var(--spacing-lg);
  margin-top: var(--spacing-2xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.footer-section h4 {
  margin-bottom: var(--spacing-sm);
  font-size: var(--font-size-lg);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--spacing-xs);
}

.footer-links a {
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
  h1 { font-size: var(--font-size-3xl); }
  h2 { font-size: var(--font-size-2xl); }
  h3 { font-size: var(--font-size-xl); }
  
  .navbar-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg-glass);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: var(--spacing-md);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  
  .navbar-menu.active {
    display: flex;
  }
  
  .navbar-toggle {
    display: block;
  }
  
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .section {
    padding: var(--spacing-xl) 0;
  }
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease-out;
}

.animate-fade-in {
  animation: fadeIn 0.6s ease-out;
}

.animate-slide-in-left {
  animation: slideInLeft 0.6s ease-out;
}

/* Scroll Reveal */
.scroll-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease-out;
}

.scroll-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}