/*
 * MEP Score Design System
 * Unified CSS variables and components for consistent UI across all pages
 */

/* ===============================================
   CSS Custom Properties (Design Tokens)
   =============================================== */

:root {
  /* Colors - Primary Palette */
  --color-primary-50: #eff6ff;
  --color-primary-100: #dbeafe;
  --color-primary-200: #bfdbfe;
  --color-primary-300: #93c5fd;
  --color-primary-400: #60a5fa;
  --color-primary-500: #3b82f6;
  --color-primary-600: #2563eb;
  --color-primary-700: #1d4ed8;
  --color-primary-800: #1e40af;
  --color-primary-900: #1e3a8a;

  /* Colors - Gray Scale */
  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2937;
  --color-gray-900: #111827;

  /* Colors - Semantic */
  --color-success-50: #ecfdf5;
  --color-success-500: #10b981;
  --color-success-600: #059669;
  --color-warning-50: #fffbeb;
  --color-warning-500: #f59e0b;
  --color-warning-600: #d97706;
  --color-error-50: #fef2f2;
  --color-error-500: #ef4444;
  --color-error-600: #dc2626;

  /* Background Colors */
  --color-bg-primary: #f5f7fa;
  --color-bg-white: #ffffff;
  --color-bg-blue-gradient: linear-gradient(to right, #dbeafe, #e0e7ff);

  /* Typography */
  --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --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;

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

  /* Border Radius */
  --border-radius-sm: 0.125rem;   /* 2px */
  --border-radius-base: 0.25rem;  /* 4px */
  --border-radius-md: 0.375rem;   /* 6px */
  --border-radius-lg: 0.5rem;     /* 8px */
  --border-radius-xl: 0.75rem;    /* 12px */
  --border-radius-2xl: 1rem;      /* 16px */
  --border-radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-base: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;

  /* Breakpoints (for CSS custom media queries) */
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  --breakpoint-2xl: 1536px;

  /* Touch Target Minimum Size */
  --touch-target-min: 44px;
}

/* ===============================================
   Base Typography System
   =============================================== */

.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-base { font-size: var(--font-size-base); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-2xl { font-size: var(--font-size-2xl); }
.text-3xl { font-size: var(--font-size-3xl); }
.text-4xl { font-size: var(--font-size-4xl); }

.font-normal { font-weight: var(--font-weight-normal); }
.font-medium { font-weight: var(--font-weight-medium); }
.font-semibold { font-weight: var(--font-weight-semibold); }
.font-bold { font-weight: var(--font-weight-bold); }

.leading-tight { line-height: var(--line-height-tight); }
.leading-normal { line-height: var(--line-height-normal); }
.leading-relaxed { line-height: var(--line-height-relaxed); }

/* ===============================================
   Unified Button System
   =============================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--touch-target-min);
  padding: var(--spacing-3) var(--spacing-4);
  border-radius: var(--border-radius-md);
  font-family: var(--font-family-base);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

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

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Button Variants */
.btn-primary {
  background-color: var(--color-primary-600);
  color: white;
  border-color: var(--color-primary-600);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-700);
  border-color: var(--color-primary-700);
}

.btn-primary:active:not(:disabled) {
  background-color: var(--color-primary-800);
  border-color: var(--color-primary-800);
}

.btn-secondary {
  background-color: var(--color-gray-100);
  color: var(--color-gray-900);
  border-color: var(--color-gray-200);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-gray-200);
  border-color: var(--color-gray-300);
}

.btn-secondary:active:not(:disabled) {
  background-color: var(--color-gray-300);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary-600);
  border-color: var(--color-primary-600);
}

.btn-outline:hover:not(:disabled) {
  background-color: var(--color-primary-50);
}

.btn-outline:active:not(:disabled) {
  background-color: var(--color-primary-100);
}

/* Button Sizes */
.btn-sm {
  min-height: var(--touch-target-min);
  padding: var(--spacing-2) var(--spacing-3);
  font-size: var(--font-size-xs);
}

.btn-lg {
  min-height: calc(var(--touch-target-min) + var(--spacing-2));
  padding: var(--spacing-4) var(--spacing-6);
  font-size: var(--font-size-base);
}

/* ===============================================
   Card System
   =============================================== */

.card {
  background-color: var(--color-bg-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.card-header {
  padding: var(--spacing-4) var(--spacing-6);
  border-bottom: 1px solid var(--color-gray-200);
  background-color: var(--color-gray-50);
}

.card-body {
  padding: var(--spacing-6);
}

.card-footer {
  padding: var(--spacing-4) var(--spacing-6);
  border-top: 1px solid var(--color-gray-200);
  background-color: var(--color-gray-50);
}

/* ===============================================
   Navigation System
   =============================================== */

.nav-primary {
  background-color: var(--color-bg-white);
  border-bottom: 1px solid var(--color-gray-200);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 50;
}

.nav-brand {
  display: flex;
  align-items: center;
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-gray-900);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.nav-brand:hover {
  color: var(--color-primary-600);
}

.nav-link {
  display: flex;
  align-items: center;
  min-height: var(--touch-target-min);
  padding: var(--spacing-3);
  color: var(--color-gray-600);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  border-radius: var(--border-radius-md);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-gray-900);
  background-color: var(--color-gray-100);
}

/* ===============================================
   Form Components
   =============================================== */

.form-input {
  display: block;
  width: 100%;
  min-height: var(--touch-target-min);
  padding: var(--spacing-3) var(--spacing-4);
  font-size: var(--font-size-sm);
  font-family: var(--font-family-base);
  line-height: var(--line-height-normal);
  color: var(--color-gray-900);
  background-color: var(--color-bg-white);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--border-radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-primary-500);
  box-shadow: 0 0 0 3px rgb(59 130 246 / 0.1);
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='m6 8 4 4 4-4'/%3e%3c/svg%3e");
  background-position: right var(--spacing-3) center;
  background-repeat: no-repeat;
  background-size: 1em 1em;
  padding-right: var(--spacing-10);
}

/* ===============================================
   Utility Classes
   =============================================== */

.container {
  width: 100%;
  max-width: 80rem; /* 1280px */
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--spacing-4);
  padding-right: var(--spacing-4);
}

@media (min-width: 640px) {
  .container {
    padding-left: var(--spacing-6);
    padding-right: var(--spacing-6);
  }
}

@media (min-width: 1024px) {
  .container {
    padding-left: var(--spacing-8);
    padding-right: var(--spacing-8);
  }
}

.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;
}

/* Touch-friendly interactive elements */
.touch-target {
  min-height: var(--touch-target-min);
  min-width: var(--touch-target-min);
}

/* ===============================================
   Responsive Typography
   =============================================== */

@media (max-width: 767px) {
  :root {
    --font-size-base: 0.875rem; /* 14px on mobile */
  }
}

/* ===============================================
   Enhanced Interactive States
   =============================================== */

/* Improved focus states for accessibility */
.btn:focus-visible,
.form-input:focus-visible,
.form-select:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
  box-shadow: 0 0 0 4px rgb(59 130 246 / 0.1);
}

/* Better touch feedback */
@media (hover: none) and (pointer: coarse) {
  .btn:active,
  .nav-link:active {
    transform: scale(0.98);
    transition: transform 100ms ease-in-out;
  }
}

/* Enhanced hover states for desktop */
@media (hover: hover) {
  .btn:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
  }
  
  .card:hover {
    box-shadow: var(--shadow-lg);
    transition: box-shadow var(--transition-base);
  }
}

/* Loading states */
.btn.loading {
  position: relative;
  color: transparent;
}

.btn.loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 20px;
  height: 20px;
  margin: -10px 0 0 -10px;
  border: 2px solid transparent;
  border-top-color: currentColor;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Modal animations */
.modal-enter {
  opacity: 0;
  transform: scale(0.9);
}

.modal-enter-active {
  opacity: 1;
  transform: scale(1);
  transition: opacity var(--transition-base), transform var(--transition-base);
}

.modal-exit {
  opacity: 1;
  transform: scale(1);
}

.modal-exit-active {
  opacity: 0;
  transform: scale(0.9);
  transition: opacity var(--transition-base), transform var(--transition-base);
}

/* Improved slider styles for touch */
.weight-slider {
  -webkit-appearance: none;
  appearance: none;
  height: 8px;
  border-radius: var(--border-radius-full);
  background: var(--color-gray-200);
  outline: none;
  opacity: 0.7;
  transition: opacity var(--transition-fast);
}

.weight-slider:hover {
  opacity: 1;
}

.weight-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: var(--border-radius-full);
  background: var(--color-primary-600);
  cursor: pointer;
  border: 2px solid white;
  box-shadow: var(--shadow-sm);
}

.weight-slider::-webkit-slider-thumb:hover {
  background: var(--color-primary-700);
  transform: scale(1.1);
}

.weight-slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: var(--border-radius-full);
  background: var(--color-primary-600);
  cursor: pointer;
  border: 2px solid white;
  box-shadow: var(--shadow-sm);
}

/* Better mobile tap targets */
@media (max-width: 767px) {
  .btn {
    min-height: 48px;
    padding: var(--spacing-3) var(--spacing-4);
  }
  
  .btn-sm {
    min-height: 44px;
    padding: var(--spacing-2) var(--spacing-3);
  }
  
  .form-input,
  .form-select {
    min-height: 48px;
    font-size: 16px; /* Prevents zoom on iOS */
  }
}

/* ===============================================
   Print Styles
   =============================================== */

@media print {
  .btn,
  .nav-primary {
    display: none;
  }
  
  .card {
    border: 1px solid #000;
    box-shadow: none;
  }
}