/**
 * ScheduleMyClasses Design System
 * Unified design tokens and CSS variables
 * Created: September 2025
 */

:root {
  /* === SEMANTIC COLOR SYSTEM === */
  
  /* Primary Brand Colors */
  --color-primary-50: #f0f4ff;
  --color-primary-100: #e0e7ff;
  --color-primary-200: #c7d2fe;
  --color-primary-300: #a5b4fc;
  --color-primary-400: #8b5cf6;
  --color-primary-500: #667eea;
  --color-primary-600: #5b21b6;
  --color-primary-700: #4c1d95;
  --color-primary-800: #3730a3;
  --color-primary-900: #1a1f36;

  /* Secondary Purple Colors */
  --color-secondary-50: #f8f4ff;
  --color-secondary-100: #ede9fe;
  --color-secondary-200: #ddd6fe;
  --color-secondary-300: #c4b5fd;
  --color-secondary-400: #a78bfa;
  --color-secondary-500: #764ba2;
  --color-secondary-600: #7c3aed;
  --color-secondary-700: #6d28d9;
  --color-secondary-800: #5b21b6;
  --color-secondary-900: #4c1d95;

  /* Neutral Colors */
  --color-neutral-50: #f8fafc;
  --color-neutral-100: #f1f5f9;
  --color-neutral-200: #e2e8f0;
  --color-neutral-300: #cbd5e1;
  --color-neutral-400: #94a3b8;
  --color-neutral-500: #64748b;
  --color-neutral-600: #475569;
  --color-neutral-700: #334155;
  --color-neutral-800: #1e293b;
  --color-neutral-900: #0f172a;

  /* Semantic Text Colors */
  --color-text-heading: #2c3e50;
  --color-text-muted: #6c757d;
  --color-text-body: #334155;

  /* Semantic Border Colors */
  --color-border-light: #e9ecef;

  /* Status Colors */
  --color-success-50: #f0fdf4;
  --color-success-100: #dcfce7;
  --color-success-500: #28a745;
  --color-success-600: #16a34a;
  --color-success-700: #15803d;

  --color-danger-50: #fef2f2;
  --color-danger-100: #fee2e2;
  --color-danger-500: #dc3545;
  --color-danger-600: #dc2626;
  --color-danger-700: #b91c1c;

  --color-warning-50: #fffbeb;
  --color-warning-100: #fef3c7;
  --color-warning-500: #ffc107;
  --color-warning-600: #d97706;
  --color-warning-700: #b45309;

  --color-info-50: #eff6ff;
  --color-info-100: #dbeafe;
  --color-info-500: #17a2b8;
  --color-info-600: #0284c7;
  --color-info-700: #0369a1;

  /* Accent Colors */
  --color-accent-warm: #ff6b6b;
  --color-accent-gold: #ffd700;
  --color-accent-green: #4ecdc4;

  /* === GRADIENTS === */
  --gradient-primary: linear-gradient(135deg, var(--color-primary-500) 0%, var(--color-secondary-500) 100%);
  --gradient-card: linear-gradient(145deg, #ffffff 0%, #f8fafc 100%);
  --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-warm: linear-gradient(135deg, var(--color-accent-warm) 0%, #ffb347 100%);
  --gradient-success: linear-gradient(135deg, var(--color-success-500) 0%, var(--color-success-600) 100%);
  --gradient-neutral: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);

  /* === SPACING SYSTEM === */
  --space-0: 0;
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */

  /* === TYPOGRAPHY === */
  --font-family-base: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-family-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;

  --font-size-xs: 0.75rem;      /* 12px */
  --font-size-sm: 0.875rem;     /* 14px */
  --font-size-base: 1rem;       /* 16px */
  --font-size-lg: 1.125rem;     /* 18px */
  --font-size-xl: 1.25rem;      /* 20px */
  --font-size-2xl: 1.5rem;      /* 24px */
  --font-size-3xl: 1.875rem;    /* 30px */
  --font-size-4xl: 2.25rem;     /* 36px */

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* === COMPONENT TOKENS === */
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-base: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 20px;
  --radius-full: 9999px;

  /* Shadows - Enhanced Modern Depth System */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-base: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  
  /* Modern Card & Button Shadows */
  --shadow-card: var(--shadow-base);
  --shadow-card-hover: var(--shadow-lg);
  --shadow-button: var(--shadow-sm);
  --shadow-button-hover: var(--shadow-base);

  /* Animations */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
  --transition-bounce: 250ms cubic-bezier(0.68, -0.55, 0.265, 1.55);

  /* === COMPONENT SPECIFIC TOKENS === */
  
  /* Buttons */
  --btn-height-sm: 32px;
  --btn-height-base: 40px;
  --btn-height-lg: 48px;
  --btn-padding-sm: var(--space-2) var(--space-3);
  --btn-padding-base: var(--space-3) var(--space-5);
  --btn-padding-lg: var(--space-4) var(--space-6);

  /* Cards */
  --card-padding: var(--space-6);
  --card-radius: var(--radius-lg);
  --card-shadow: var(--shadow-base);
  --card-shadow-hover: var(--shadow-lg);

  /* Modals */
  --modal-backdrop: rgba(0, 0, 0, 0.1);
  --modal-radius: var(--radius-lg);
  --modal-shadow: var(--shadow-2xl);
  --modal-max-width: 500px;
  --modal-spacing: 120px; /* Distance from navbar */

  /* Navigation */
  --nav-height: 60px;
  --nav-bg: rgba(255, 255, 255, 0.95);
  --nav-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  --nav-backdrop-blur: blur(20px);

  /* Forms */
  --form-input-height: 40px;
  --form-input-padding: var(--space-3) var(--space-4);
  --form-input-radius: var(--radius-base);
  --form-input-border: 1px solid var(--color-neutral-300);
  --form-input-focus: 0 0 0 3px rgba(102, 126, 234, 0.1);
  
  /* Form Typography */
  --form-label-font-size: var(--font-size-sm);     /* 14px - consistent labels */
  --form-input-font-size: var(--font-size-sm);     /* 14px - compact but readable */
  --form-select-font-size: var(--font-size-sm);    /* 14px - dropdown consistency */
  --form-textarea-font-size: var(--font-size-sm);  /* 14px - text area consistency */
  --form-help-font-size: var(--font-size-xs);      /* 12px - help text smaller */
  
  /* Button Typography */
  --btn-font-size: var(--font-size-sm);            /* 14px - compact button text */
  
  /* Standard Margins - for consistent spacing across the site */
  --page-margin-bottom: 3rem;      /* Standard bottom margin for pages */
  --section-margin-bottom: 2rem;   /* Margin between major sections */
  --element-margin-bottom: 1rem;   /* Margin between elements */
  --button-margin-bottom: 2rem;    /* Standard spacing after buttons */
}

/* === DARK MODE SUPPORT === */
@media (prefers-color-scheme: dark) {
  :root {
    /* Override specific colors for dark mode */
    --color-neutral-50: #0f172a;
    --color-neutral-100: #1e293b;
    --color-neutral-200: #334155;
    --color-neutral-900: #f8fafc;
    
    --nav-bg: rgba(15, 23, 42, 0.95);
    --modal-backdrop: rgba(0, 0, 0, 0.3);
  }
}

/* === LEGACY VARIABLE ALIASES === */
/* For backward compatibility with existing templates */
:root {
  --primary-gradient: var(--gradient-primary);
  --primary-color: var(--color-primary-500);
  --secondary-color: var(--color-neutral-600);
  --success-color: var(--color-success-500);
  --danger-color: var(--color-danger-500);
  --warning-color: var(--color-warning-500);
  --info-color: var(--color-info-500);
  --light-color: var(--color-neutral-50);
  --dark-color: var(--color-neutral-900);
  --border-radius: var(--radius-lg);
  --box-shadow: var(--shadow-base);
  --transition: var(--transition-base);
  --accent-warm: var(--color-accent-warm);
  --accent-gold: var(--color-accent-gold);
  --accent-green: var(--color-accent-green);
}

/* === UTILITY CLASSES === */
.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
}