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

/* =========================
   ROOT THEME VARIABLES
   ========================= */
:root {
  /* Color Palette */
  --primary-900: #0f0b23;
  --primary-800: #1a1a2e;
  --primary-700: #16213e;
  --primary-600: #0f3460;
  --primary-500: #533483;
  --primary-400: #7209b7;
  --primary-300: #a663cc;
  --primary-200: #c8a8e9;
  --primary-100: #e5d4f1;
  
  --accent-500: #ff6b6b;
  --accent-400: #ff8787;
  --accent-300: #ffa8a8;
  
  --success-500: #51cf66;
  --success-400: #69db7c;
  
  --warning-500: #ffd43b;
  --warning-400: #ffe066;
  
  --neutral-900: #0c0c0d;
  --neutral-800: #1a1b1e;
  --neutral-700: #2d2e33;
  --neutral-600: #43454a;
  --neutral-500: #5a5d63;
  --neutral-400: #9ca3af;
  --neutral-300: #d1d5db;
  --neutral-200: #e5e7eb;
  --neutral-100: #f3f4f6;
  --neutral-50: #f9fafb;
  
  /* Semantic Colors */
  --bg-primary: var(--primary-900);
  --bg-secondary: var(--primary-800);
  --bg-tertiary: var(--primary-700);
  --bg-surface: var(--neutral-800);
  --bg-surface-elevated: var(--neutral-700);
  
  --text-primary: var(--neutral-100);
  --text-secondary: var(--neutral-300);
  --text-muted: var(--neutral-400);
  --text-inverse: var(--neutral-900);
  
  --border-subtle: var(--neutral-700);
  --border-default: var(--neutral-600);
  --border-strong: var(--neutral-500);
  
  /* Typography */
  --font-family-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-family-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
  
  --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: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  /* Spacing Scale */
  --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;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-base: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-2xl: 2rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-base: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1), 0 2px 4px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15), 0 8px 10px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.25);
  
  --shadow-glow: 0 0 0 1px rgba(255, 255, 255, 0.05), 0 1px 0 rgba(255, 255, 255, 0.05);
  --shadow-primary: 0 8px 32px rgba(83, 52, 131, 0.3);
  --shadow-accent: 0 8px 32px rgba(255, 107, 107, 0.3);
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--primary-600) 0%, var(--primary-500) 50%, var(--primary-400) 100%);
  --gradient-accent: linear-gradient(135deg, var(--accent-500) 0%, var(--accent-400) 100%);
  --gradient-surface: linear-gradient(145deg, var(--bg-surface) 0%, var(--bg-surface-elevated) 100%);
  --gradient-glass: linear-gradient(145deg, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0.05) 100%);
  
  /* Glass Morphism */
  --glass-bg: rgba(255, 255, 255, 0.08);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-backdrop: blur(20px);
}

/* =========================
   BASE STYLES
   ========================= */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  padding: 0;
  background: var(--bg-primary);
  background-image: 
    radial-gradient(circle at 25% 25%, var(--primary-800) 0%, transparent 50%),
    radial-gradient(circle at 75% 75%, var(--primary-700) 0%, transparent 50%);
  color: var(--text-primary);
  font-family: var(--font-family-sans);
  font-weight: var(--font-weight-normal);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

/* =========================
   GAME CONTAINER
   ========================= */
.game-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-6);
  width: 100%;
  height: 100vh;
  position: relative;
}

canvas {
  display: block;
  background: var(--gradient-surface);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-2xl), var(--shadow-glow);
  border: 1px solid var(--glass-border);
  backdrop-filter: var(--glass-backdrop);
}

/* =========================
   SCREEN SYSTEM
   ========================= */
.screen {
  position: fixed;
  top: 15%;
  left: 0;
  width: 100vw;
  height: 100vh;
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(15, 11, 35, 0.95);
  backdrop-filter: blur(30px);
  z-index: 1000;
  padding: var(--space-8);
}

.screen.show {
  display: flex;
}

.screen-content {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-12);
  width: 100%;
  max-width: 900px;
  max-height: 90vh;
  overflow-y: auto;
  backdrop-filter: var(--glass-backdrop);
  box-shadow: var(--shadow-2xl);
  position: relative;
}

.screen-content::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-2xl);
  padding: 1px;
  background: var(--gradient-primary);
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: xor;
  opacity: 0.3;
  pointer-events: none;
}

/* =========================
   TYPOGRAPHY
   ========================= */
.main-title {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
  margin: 0 0 var(--space-8) 0;
  text-align: center;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  background: var(--gradient-primary);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 0 30px rgba(83, 52, 131, 0.5);
}

h2 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin: 0 0 var(--space-6) 0;
  text-align: center;
}

h3 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-medium);
  color: var(--text-secondary);
  margin: 0 0 var(--space-4) 0;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* =========================
   BUTTONS
   ========================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border: none;
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  user-select: none;
}

.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  transform: translateX(-100%);
  transition: transform var(--transition-base);
}

.btn:hover::before {
  transform: translateX(100%);
}

/* Button Variants */
.menu-btn, .btn-primary {
  background: var(--gradient-primary);
  color: var(--text-primary);
  box-shadow: var(--shadow-primary), var(--shadow-glow);
  border: 1px solid var(--glass-border);
}

.menu-btn:hover, .btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl), 0 0 40px rgba(83, 52, 131, 0.4);
}

.menu-btn:active, .btn-primary:active {
  transform: translateY(0);
  box-shadow: var(--shadow-md);
}

.danger-btn, .btn-danger {
  background: var(--gradient-accent);
  color: var(--text-primary);
  box-shadow: var(--shadow-accent), var(--shadow-glow);
  border: 1px solid rgba(255, 107, 107, 0.2);
}

.danger-btn:hover, .btn-danger:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl), 0 0 40px rgba(255, 107, 107, 0.4);
}

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

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

/* =========================
   FORM ELEMENTS
   ========================= */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 8px;
  background: var(--bg-surface);
  border-radius: var(--radius-full);
  outline: none;
  border: 1px solid var(--border-subtle);
  position: relative;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--gradient-primary);
  border: 2px solid var(--text-primary);
  border-radius: var(--radius-full);
  cursor: pointer;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-lg);
}

/* =========================
   CHARACTER SELECTION
   ========================= */
.char-select-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  width: 100%;
  margin-bottom: var(--space-8);
}

.team-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.team-grid {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  min-height: 200px;
  position: relative;
  backdrop-filter: var(--glass-backdrop);
  transition: all var(--transition-base);
}

.team-grid.drop-active {
  border-color: var(--primary-400);
  background: rgba(83, 52, 131, 0.1);
  box-shadow: 0 0 0 2px rgba(83, 52, 131, 0.3);
}

.available-chars {
  grid-column: 1 / -1;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  backdrop-filter: var(--glass-backdrop);
}

.chars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-4);
}

/* Character Cards */
.char-display {
  background: var(--gradient-surface);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  user-select: none;
}

.char-display:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-400);
}

.char-display.dragging {
  opacity: 0.5;
  transform: rotate(5deg);
}

.char-name {
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.char-control {
  font-size: var(--font-size-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.char-control.human {
  color: var(--success-400);
}

.char-control.ai {
  color: var(--warning-400);
}

.delete-btn {
  position: absolute;
  top: var(--space-2);
  right: var(--space-2);
  width: 24px;
  height: 24px;
  background: var(--accent-500);
  color: var(--text-primary);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-bold);
  opacity: 0;
  transition: all var(--transition-fast);
  z-index: 10;
}

.char-display:hover .delete-btn {
  opacity: 1;
}

.delete-btn:hover {
  background: var(--accent-400);
  transform: scale(1.1);
}

/* Team Controls */
.team-controls {
  display: flex;
  justify-content: center;
  gap: var(--space-6);
  margin-top: var(--space-6);
}

.toggle-btn {
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-xs);
  border-radius: var(--radius-sm);
  min-width: 80px;
}

/* Navigation */
.nav-controls {
  display: flex;
  justify-content: center;
  gap: var(--space-4);
  margin-top: var(--space-8);
}

/* =========================
   UTILITIES
   ========================= */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.space-x-4 > * + * { margin-left: var(--space-4); }
.space-y-4 > * + * { margin-top: var(--space-4); }
.text-center { text-align: center; }
.w-full { width: 100%; }

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

@keyframes slideIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.screen.show .screen-content {
  animation: slideIn var(--transition-base) ease-out;
}

.char-display {
  animation: fadeIn var(--transition-base) ease-out;
}

/* =========================
   RESPONSIVE DESIGN
   ========================= */
@media (max-width: 768px) {
  .screen-content {
    padding: var(--space-6);
    margin: var(--space-4);
  }
  
  .char-select-container {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  
  .chars-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  }
  
  .main-title {
    font-size: var(--font-size-3xl);
  }
}

/* =========================
   DARK MODE ALTERNATIVE
   (Uncomment to switch themes)
   ========================= */
/*
:root {
  --primary-900: #0a0a0a;
  --primary-800: #1a1a1a;
  --bg-primary: var(--primary-900);
  --bg-secondary: var(--primary-800);
}
*/

.menu-btn, .pause-btn, .settings-btn {
  border: none;
  border-radius: 12px;
  padding: 12px 24px;
  color: #fff;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  background-image: linear-gradient(135deg, #6a85b6 0%, #bac8e0 100%);
  box-shadow: 0 4px 15px rgba(106, 133, 182, 0.4);
  transition: all 0.3s ease;
  margin: 10px;
}

.menu-btn:hover, .pause-btn:hover, .settings-btn:hover {
  background-image: linear-gradient(135deg, #bac8e0 0%, #6a85b6 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(106, 133, 182, 0.6);
}

.menu-btn:active, .pause-btn:active, .settings-btn:active {
  transform: translateY(0);
  box-shadow: 0 2px 10px rgba(106, 133, 182, 0.3);
}