/**
 * ST INTERNATIONAL GROUP - Unified Design System
 * Based on stage.stinternational.org master template
 * Version: 1.0.0
 */

/* ========================================
   1. CSS CUSTOM PROPERTIES (Variables)
   ======================================== */
:root {
  /* Primary Colors - Dark Theme */
  --color-bg-primary: #0B0C0F;
  --color-bg-secondary: #14171C;
  --color-bg-card: #1a1d24;
  --color-bg-elevated: #20242c;
  
  /* Accent Colors - Electric Blue */
  --color-accent: #4F6BFF;
  --color-accent-hover: #3d5aee;
  --color-accent-light: #6b85ff;
  
  /* Text Colors */
  --color-text-primary: #F2F4F8;
  --color-text-secondary: #A6AFBF;
  --color-text-muted: #6b7280;
  
  /* Border & Divider */
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-strong: rgba(255, 255, 255, 0.15);
  
  /* Semantic Colors */
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;
  
  /* HSL Variables for Tailwind-like usage */
  --background: 220 14% 4%;
  --foreground: 220 20% 97%;
  --card: 220 12% 8%;
  --card-foreground: 220 20% 97%;
  --primary: 227 100% 65%;
  --primary-foreground: 0 0% 100%;
  --secondary: 220 12% 12%;
  --secondary-foreground: 220 20% 97%;
  --muted: 220 12% 15%;
  --muted-foreground: 220 10% 70%;
  --accent: 227 100% 65%;
  --accent-foreground: 0 0% 100%;
  --border: 220 10% 18%;
  --input: 220 10% 18%;
  --ring: 227 100% 65%;
  --radius: 0.625rem;
  
  /* Typography */
  --font-heading: 'Space Grotesk', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  
  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;
  
  /* Font Weights */
  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  
  /* Spacing (8px grid) */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6), 0 10px 10px -5px rgba(0, 0, 0, 0.4);
  --shadow-accent: 0 4px 20px rgba(79, 107, 255, 0.3);
  --shadow-accent-lg: 0 8px 30px rgba(79, 107, 255, 0.4);
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-3xl: 2rem;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
  --transition-bounce: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
  
  /* Container */
  --container-max: 1400px;
  --container-padding: 1.5rem;
}

/* ========================================
   2. BASE STYLES & RESET
   ======================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

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

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-normal);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* ========================================
   3. TYPOGRAPHY UTILITIES
   ======================================== */
.font-heading {
  font-family: var(--font-heading);
}

.font-body {
  font-family: var(--font-body);
}

/* Heading Styles */
.heading-hero {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 6vw, 4rem);
  font-weight: var(--font-bold);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
}

.heading-section {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw, 3rem);
  font-weight: var(--font-bold);
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
}

.heading-card {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  line-height: 1.3;
  color: var(--color-text-primary);
}

/* Text Styles */
.text-body {
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text-secondary);
}

.text-small {
  font-size: var(--text-sm);
  line-height: 1.5;
  color: var(--color-text-secondary);
}

.text-micro {
  font-size: 11px;
  font-weight: var(--font-semibold);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

/* Text Colors */
.text-primary { color: var(--color-text-primary); }
.text-secondary { color: var(--color-text-secondary); }
.text-muted { color: var(--color-text-muted); }
.text-accent { color: var(--color-accent); }

/* Text Gradient */
.text-gradient {
  background: linear-gradient(135deg, #F2F4F8 0%, #A6AFBF 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-gradient-accent {
  background: linear-gradient(135deg, #4F6BFF 0%, #8B5CF6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ========================================
   4. LAYOUT UTILITIES
   ======================================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.container-narrow {
  max-width: 1200px;
}

.section {
  padding: var(--space-24) 0;
}

.section-lg {
  padding: var(--space-32) 0;
}

.section-sm {
  padding: var(--space-16) 0;
}

/* Grid Systems */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-8);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
}

/* Flexbox */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* ========================================
   5. COMPONENT STYLES
   ======================================== */

/* --- Cards --- */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  transition: all var(--transition-normal);
}

.card:hover {
  border-color: var(--color-border-strong);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card-glass {
  background: rgba(20, 23, 28, 0.6);
  backdrop-filter: blur(20px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-6);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  border-radius: var(--radius-lg);
  transition: all var(--transition-normal);
  cursor: pointer;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-hover) 100%);
  color: white;
  box-shadow: var(--shadow-accent);
  border: none;
}

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

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--color-border-strong);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border: none;
}

.btn-ghost:hover {
  color: var(--color-text-primary);
  background: rgba(255, 255, 255, 0.05);
}

/* --- Forms --- */
.form-input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text-primary);
  font-size: var(--text-base);
  transition: all var(--transition-normal);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(79, 107, 255, 0.15);
}

.form-input::placeholder {
  color: var(--color-text-muted);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-2);
}

/* --- Badges --- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-accent {
  background: rgba(79, 107, 255, 0.15);
  color: var(--color-accent-light);
}

.badge-outline {
  background: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
}

/* --- Dividers --- */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  width: 100%;
}

.divider-vertical {
  width: 1px;
  height: 100%;
  background: linear-gradient(180deg, transparent, rgba(255, 255, 255, 0.1), transparent);
}

/* ========================================
   6. UTILITY CLASSES
   ======================================== */

/* Spacing */
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }
.py-8 { padding-top: var(--space-8); padding-bottom: var(--space-8); }
.py-16 { padding-top: var(--space-16); padding-bottom: var(--space-16); }
.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }
.px-6 { padding-left: var(--space-6); padding-right: var(--space-6); }

/* Visibility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

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

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

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

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

.animate-fade-in-up {
  animation: fadeInUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.animate-slide-in-left {
  animation: slideInLeft 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.animate-float {
  animation: float 3s ease-in-out infinite;
}

/* Stagger delays */
.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }
.delay-400 { animation-delay: 400ms; }
.delay-500 { animation-delay: 500ms; }

/* ========================================
   7. SCROLLBAR STYLING
   ======================================== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-primary);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #2a2d35, #1f2229);
  border-radius: 4px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, #3a3d45, #2a2d35);
}

/* ========================================
   8. RESPONSIVE UTILITIES
   ======================================== */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .container {
    --container-padding: 1.5rem;
  }
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .heading-hero {
    font-size: clamp(1.75rem, 8vw, 2.5rem);
  }
  
  .section {
    padding: var(--space-16) 0;
  }
  
  .container {
    --container-padding: 1rem;
  }
}

@media (max-width: 480px) {
  .btn {
    width: 100%;
  }
  
  .card,
  .card-glass {
    padding: var(--space-4);
  }
}