/* ==========================================================================
   InvoiceMedley Design System - Global Styles & Variables
   ========================================================================== */

:root {
  /* Primary Colors - Modern Blue Palette */
  --primary-50: #eff6ff;
  --primary-100: #dbeafe;
  --primary-200: #bfdbfe;
  --primary-300: #93c5fd;
  --primary-400: #60a5fa;
  --primary-500: #3b82f6;
  --primary-600: #2563eb;
  --primary-700: #1d4ed8;
  --primary-800: #1e40af;
  --primary-900: #1e3a8a;
  
  /* Semantic Colors */
  --primary: var(--primary-600);
  --primary-hover: var(--primary-700);
  --primary-light: var(--primary-100);
  
  /* Secondary Colors */
  --secondary: #6366f1;
  --secondary-hover: #4f46e5;
  
  /* Success, Warning, Danger */
  --success: #10b981;
  --success-light: #d1fae5;
  --success-dark: #065f46;
  
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --warning-dark: #92400e;
  
  --danger: #ef4444;
  --danger-light: #fee2e2;
  --danger-dark: #991b1b;
  
  --info: #0ea5e9;
  --info-light: #e0f2fe;
  --info-dark: #075985;
  
  /* Neutral Colors */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Text Colors */
  --text-primary: var(--gray-900);
  --text-secondary: var(--gray-600);
  --text-muted: var(--gray-500);
  --text-disabled: var(--gray-400);
  --text-white: #ffffff;
  
  /* Background Colors */
  --bg-primary: #ffffff;
  --bg-secondary: var(--gray-50);
  --bg-tertiary: var(--gray-100);
  --bg-overlay: rgba(0, 0, 0, 0.5);
  
  /* Legacy Aliases (for backward compatibility) */
  --primary-color: var(--primary);
  --light-color: var(--gray-100);
  --dark-color: var(--gray-800);
  --text-color: var(--text-primary);
  
  /* Border Colors */
  --border-light: var(--gray-200);
  --border-medium: var(--gray-300);
  --border-dark: var(--gray-400);
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-md: 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);
  
  /* Spacing Scale */
  --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-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  --font-display: 'Poppins', var(--font-sans);
  
  --text-xs: 0.75rem;     /* 12px */
  --text-sm: 0.875rem;    /* 14px */
  --text-base: 1rem;      /* 16px */
  --text-lg: 1.125rem;    /* 18px */
  --text-xl: 1.25rem;     /* 20px */
  --text-2xl: 1.5rem;     /* 24px */
  --text-3xl: 1.875rem;   /* 30px */
  --text-4xl: 2.25rem;    /* 36px */
  --text-5xl: 3rem;       /* 48px */
  
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  --font-extrabold: 800;
  
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.75;
  
  /* Border Radius */
  --radius-sm: 0.25rem;   /* 4px */
  --radius: 0.5rem;       /* 8px */
  --radius-md: 0.75rem;   /* 12px */
  --radius-lg: 1rem;      /* 16px */
  --radius-xl: 1.5rem;    /* 24px */
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Z-Index Scale */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
  --z-toast: 1080;
  
  /* Layout */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
  --container-2xl: 1536px;
}

/* ==========================================================================
   Global Resets & Base Styles
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--text-primary);
  background-color: var(--bg-secondary);
}

/* ==========================================================================
   Loading States
   ========================================================================== */

.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition), visibility var(--transition);
}

.loading-overlay.active {
  opacity: 1;
  visibility: visible;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--primary-200);
  border-top-color: var(--primary);
  border-radius: var(--radius-full);
  animation: spin 0.8s linear infinite;
}

.spinner-sm {
  width: 24px;
  height: 24px;
  border-width: 3px;
}

.spinner-lg {
  width: 64px;
  height: 64px;
  border-width: 5px;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.loading-dots {
  display: inline-flex;
  gap: var(--space-2);
}

.loading-dots span {
  width: 8px;
  height: 8px;
  background: var(--primary);
  border-radius: var(--radius-full);
  animation: bounce 1.4s infinite ease-in-out both;
}

.loading-dots span:nth-child(1) {
  animation-delay: -0.32s;
}

.loading-dots span:nth-child(2) {
  animation-delay: -0.16s;
}

@keyframes bounce {
  0%, 80%, 100% {
    transform: scale(0);
  }
  40% {
    transform: scale(1);
  }
}

/* ==========================================================================
   Toast Notifications
   ========================================================================== */

.toast-container {
  position: fixed;
  top: var(--space-6);
  right: var(--space-6);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 420px;
  width: 100%;
  pointer-events: none;
}

.toast {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  padding: var(--space-4) var(--space-5);
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  pointer-events: all;
  transform: translateX(calc(100% + var(--space-6)));
  opacity: 0;
  transition: all var(--transition-slow);
}

.toast.show {
  transform: translateX(0);
  opacity: 1;
}

.toast-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-sm);
}

.toast-content {
  flex: 1;
  min-width: 0;
}

.toast-title {
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-1);
}

.toast-message {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.toast-close {
  flex-shrink: 0;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.toast-close:hover {
  color: var(--text-primary);
}

/* Toast Variants */
.toast.success {
  border-left: 4px solid var(--success);
}

.toast.success .toast-icon {
  background: var(--success-light);
  color: var(--success-dark);
}

.toast.error {
  border-left: 4px solid var(--danger);
}

.toast.error .toast-icon {
  background: var(--danger-light);
  color: var(--danger-dark);
}

.toast.warning {
  border-left: 4px solid var(--warning);
}

.toast.warning .toast-icon {
  background: var(--warning-light);
  color: var(--warning-dark);
}

.toast.info {
  border-left: 4px solid var(--info);
}

.toast.info .toast-icon {
  background: var(--info-light);
  color: var(--info-dark);
}

/* ==========================================================================
   Smooth Transitions & Animations
   ========================================================================== */

.fade-in {
  animation: fadeIn var(--transition-slow) ease-in;
}

.slide-up {
  animation: slideUp var(--transition-slow) ease-out;
}

.scale-in {
  animation: scaleIn var(--transition) ease-out;
}

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

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

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

/* Hover & Focus Transitions */
.transition-all {
  transition: all var(--transition);
}

.transition-colors {
  transition-property: color, background-color, border-color;
  transition-duration: var(--transition);
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

.transition-transform {
  transition: transform var(--transition);
}

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

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

.truncate {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.line-clamp-2 {
  overflow: hidden;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.line-clamp-3 {
  overflow: hidden;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
}

/* ==========================================================================
   Mobile Responsiveness
   ========================================================================== */

@media (max-width: 768px) {
  .toast-container {
    left: var(--space-4);
    right: var(--space-4);
    max-width: none;
  }
  
  .loading-overlay .spinner {
    width: 40px;
    height: 40px;
  }
}