/* === UNIFIED DESIGN SYSTEM === */

/* === ROOT VARIABLES === */
:root {
  /* Color Palette - Professional Dark Theme */
  --primary: #ff2a2a;
  --primary-light: #ff5252;
  --primary-dark: #d32f2f;
  --accent-blue: #2a7fff;
  --accent-blue-light: #5fa8ff;
  --accent-purple: #8a2be2;
  --accent-purple-light: #a855f7;
  --success: #4caf50;
  --warning: #ff9800;
  --error: #f44336;
  --info: #2196f3;
  
  /* Background & Surfaces */
  --bg-primary: #0a0b14;
  --bg-secondary: #0f0f1a;
  --bg-tertiary: #1a1a2e;
  --bg-card: rgba(25, 25, 40, 0.35);
  --bg-glass: rgba(15, 15, 30, 0.25);
  --bg-hover: rgba(255, 42, 42, 0.08);
  
  /* Text Colors */
  --text-primary: #f0f0f0;
  --text-secondary: #b0b0c0;
  --text-muted: #8888a0;
  --text-dark: #333;
  --text-light: #fff;
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--primary), var(--accent-purple));
  --gradient-secondary: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  --gradient-tertiary: linear-gradient(135deg, rgba(138,43,226,0.08), transparent 40%);
  --gradient-bg: radial-gradient(ellipse at 20% 30%, rgba(138,43,226,0.08), transparent 40%),
                 radial-gradient(ellipse at 80% 70%, rgba(42,127,255,0.08), transparent 40%),
                 radial-gradient(circle at center, var(--bg-primary) 0%, #050508 100%);
  
  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', monospace;
  --font-display: 'Poppins', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-arabic: 'Cairo', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --font-cjk: 'Noto Sans SC', 'Noto Sans JP', 'Microsoft YaHei', 'Hiragino Sans', sans-serif;
  
  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  
  /* Layout */
  --max-width: 1400px;
  --max-width-narrow: 1200px;
  --border-radius: 12px;
  --border-radius-sm: 6px;
  --border-radius-lg: 16px;
  --border-radius-xl: 24px;
  
  /* 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-xl: 0 15px 50px rgba(0, 0, 0, 0.8);
  --shadow-glow: 0 0 20px rgba(255, 42, 42, 0.3);
  
  /* Transitions */
  --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Z-index */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

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

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

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

body {
  font-family: var(--font-primary);
  color: var(--text-primary);
  background: var(--gradient-bg);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.6;
  /* Header spacing is handled in header.css */
}

/* Language-specific fonts */
:lang(zh), :lang(ja), :lang(ko) { 
  font-family: var(--font-cjk); 
}
:lang(ar) { 
  font-family: var(--font-arabic); 
  direction: rtl; 
}
:lang(en), :lang(de), :lang(ru), :lang(pt), :lang(tr), :lang(es), :lang(fr) {
  font-family: var(--font-primary);
}

/* === TYPOGRAPHY === */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--space-md);
  color: var(--text-primary);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
}

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

a:hover {
  color: var(--primary-light);
  text-decoration: none;
}

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

.container-narrow {
  max-width: var(--max-width-narrow);
}

.section {
  padding: var(--space-3xl) 0;
}

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

.section-lg {
  padding: var(--space-3xl) 0;
}

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

.grid-responsive {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

/* === FLEXBOX UTILITIES === */
.flex {
  display: flex;
}

.flex-column {
  flex-direction: column;
}

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

.flex-between {
  justify-content: space-between;
  align-items: center;
}

.flex-wrap {
  flex-wrap: wrap;
}

.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.gap-xl { gap: var(--space-xl); }

/* === COMPONENTS === */

/* Button Styles */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-md) var(--space-xl);
  border: none;
  border-radius: var(--border-radius);
  font-family: var(--font-primary);
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  cursor: pointer;
  transition: var(--transition-normal);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  color: var(--text-light);
}

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

.btn-secondary:hover {
  background: var(--primary);
  color: var(--text-light);
  transform: translateY(-2px);
}

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

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

.btn-sm {
  padding: var(--space-sm) var(--space-md);
  font-size: 0.8rem;
}

.btn-lg {
  padding: var(--space-lg) var(--space-2xl);
  font-size: 1rem;
}

/* Card Styles */
.card {
  background: var(--bg-card);
  border: 1px solid rgba(255, 42, 42, 0.1);
  border-radius: var(--border-radius-lg);
  padding: var(--space-xl);
  backdrop-filter: blur(16px);
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

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

.card-header {
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-md);
  border-bottom: 1px solid rgba(255, 42, 42, 0.1);
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.card-subtitle {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Form Styles */
.form-group {
  margin-bottom: var(--space-lg);
}

.form-label {
  display: block;
  margin-bottom: var(--space-sm);
  font-weight: 500;
  color: var(--text-primary);
}

.form-input {
  width: 100%;
  padding: var(--space-md);
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 42, 42, 0.2);
  border-radius: var(--border-radius);
  color: var(--text-primary);
  font-family: var(--font-primary);
  font-size: 1rem;
  transition: var(--transition-normal);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(255, 42, 42, 0.1);
}

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

/* === ANIMATIONS === */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideInUp {
  from { opacity: 0; transform: translateY(40px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulseGlow {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.85; transform: scale(1.02); }
}

@keyframes particleFloat {
  0% { transform: translateY(100vh) translateX(0); opacity: 0; }
  5% { opacity: 0.6; }
  95% { opacity: 0.6; }
  100% { transform: translateY(-100px) translateX(100px); opacity: 0; }
}

/* === UTILITIES === */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }

.bg-primary { background-color: var(--primary); }
.bg-secondary { background-color: var(--bg-secondary); }
.bg-card { background-color: var(--bg-card); }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

.p-sm { padding: var(--space-sm); }
.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.p-xl { padding: var(--space-xl); }

/* === RESPONSIVE DESIGN === */
@media (max-width: 768px) {
  h1 { font-size: 2.5rem; }
  h2 { font-size: 2rem; }
  h3 { font-size: 1.5rem; }
  
  .container {
    padding: 0 var(--space-md);
  }
  
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .btn {
    padding: var(--space-sm) var(--space-lg);
  }
  
  .section {
    padding: var(--space-2xl) 0;
  }
}

@media (max-width: 480px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  
  .container {
    padding: 0 var(--space-sm);
  }
  
  .card {
    padding: var(--space-lg);
  }
}

/* === ACCESSIBILITY === */
.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;
}

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

/* === PRINT STYLES === */
@media print {
  body {
    background: white;
    color: black;
  }
  
  .btn,
  .card {
    box-shadow: none;
    border: 1px solid #ccc;
  }
}