/*
================================================================================
AUTO PARTS E-COMMERCE - BASE STYLESHEET
Modern, Industrial, Professional Design System
================================================================================
*/

/* ============================================================================
   CSS VARIABLES - Design Tokens
   ========================================================================= */
:root {
  /* COLOR PALETTE - Industrial & Professional */
  --color-background: #FFFFFF;
  --color-surface: #F5F7F9;
  --color-surface-dark: #E8ECEF;
  
  --color-text-primary: #1A1D23;
  --color-text-secondary: #4A5568;
  --color-text-muted: #718096;
  --color-text-inverse: #FFFFFF;
  
  /* Brand Colors - Industrial Theme */
  --color-primary: #2C5F8D;        /* Steel Blue */
  --color-primary-dark: #1E4466;
  --color-primary-light: #3A7AB0;
  --color-primary-hover: #234B72;
  
  --color-secondary: #3D4451;      /* Industrial Gray */
  --color-secondary-dark: #2A2F3A;
  --color-secondary-light: #4F5663;
  
  --color-accent: #FDB913;         /* Hazard Yellow */
  --color-accent-dark: #E5A20F;
  --color-accent-light: #FECA4B;
  
  --color-metallic: #A8B2BD;       /* Metallic Silver */
  --color-metallic-light: #C5CDD5;
  --color-metallic-dark: #8A96A3;
  
  /* Semantic Colors */
  --color-success: #28A745;
  --color-success-light: #D4EDDA;
  --color-success-dark: #1E7E34;
  
  --color-warning: #FDB913;
  --color-warning-light: #FFF3CD;
  --color-warning-dark: #E5A20F;
  
  --color-danger: #DC3545;
  --color-danger-light: #F8D7DA;
  --color-danger-dark: #BD2130;
  
  --color-info: #17A2B8;
  --color-info-light: #D1ECF1;
  --color-info-dark: #117A8B;
  
  /* Neutral Grays - Industrial 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;
  
  --color-black: #000000;
  --color-white: #FFFFFF;
  
  /* Border Colors */
  --color-border: #D1D5DB;
  --color-border-light: #E5E7EB;
  --color-border-dark: #9CA3AF;
  --color-border-focus: #2C5F8D;
  
  /* TYPOGRAPHY */
  --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  --font-family-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  --font-family-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
  
  /* Font Sizes - Modular Scale */
  --font-size-xs: 0.75rem;      /* 12px */
  --font-size-sm: 0.875rem;     /* 14px */
  --font-size-base: 1rem;       /* 16px */
  --font-size-md: 1.125rem;     /* 18px */
  --font-size-lg: 1.25rem;      /* 20px */
  --font-size-xl: 1.5rem;       /* 24px */
  --font-size-2xl: 1.875rem;    /* 30px */
  --font-size-3xl: 2.25rem;     /* 36px */
  --font-size-4xl: 3rem;        /* 48px */
  --font-size-5xl: 3.75rem;     /* 60px */
  
  /* Font Weights */
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  
  /* Line Heights */
  --line-height-tight: 1.25;
  --line-height-snug: 1.375;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  --line-height-loose: 2;
  
  /* Letter Spacing */
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  --letter-spacing-wider: 0.05em;
  --letter-spacing-widest: 0.1em;
  
  /* SPACING SCALE - 4px base unit */
  --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 */
  --space-24: 6rem;      /* 96px */
  
  /* BORDER RADIUS */
  --radius-none: 0;
  --radius-sm: 0.125rem;    /* 2px */
  --radius-base: 0.25rem;   /* 4px */
  --radius-md: 0.375rem;    /* 6px */
  --radius-lg: 0.5rem;      /* 8px */
  --radius-xl: 0.75rem;     /* 12px */
  --radius-2xl: 1rem;       /* 16px */
  --radius-full: 9999px;
  
  /* SHADOWS - Industrial Depth */
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-base: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);
  --shadow-outline: 0 0 0 3px rgba(44, 95, 141, 0.2);
  
  /* TRANSITIONS */
  --transition-fast: 150ms;
  --transition-base: 200ms;
  --transition-medium: 300ms;
  --transition-slow: 500ms;
  
  --transition-ease: cubic-bezier(0.4, 0, 0.2, 1);
  --transition-ease-in: cubic-bezier(0.4, 0, 1, 1);
  --transition-ease-out: cubic-bezier(0, 0, 0.2, 1);
  --transition-ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Z-INDEX SCALE */
  --z-index-dropdown: 1000;
  --z-index-sticky: 1020;
  --z-index-fixed: 1030;
  --z-index-modal-backdrop: 1040;
  --z-index-modal: 1050;
  --z-index-popover: 1060;
  --z-index-tooltip: 1070;
  
  /* LAYOUT */
  --container-max-width: 1280px;
  --container-padding: var(--space-4);
  --grid-gap: var(--space-6);
  
  /* MISC */
  --border-width: 1px;
  --border-width-thick: 2px;
  --focus-ring-width: 3px;
  --focus-ring-offset: 2px;
}

/* Dark Mode Variables (Optional for future implementation) */
@media (prefers-color-scheme: dark) {
  :root {
    --color-background: #111827;
    --color-surface: #1F2937;
    --color-surface-dark: #374151;
    --color-text-primary: #F9FAFB;
    --color-text-secondary: #D1D5DB;
    --color-text-muted: #9CA3AF;
  }
}

/* ============================================================================
   CSS RESET & NORMALIZE
   ========================================================================= */

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

/* Document & Root */
html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Body */
body {
  margin: 0;
  padding: 0;
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-background);
  min-height: 100vh;
  overflow-x: hidden;
}

/* Remove default margins */
h1, h2, h3, h4, h5, h6,
p, blockquote, pre,
ul, ol, dl,
figure, fieldset {
  margin: 0;
  padding: 0;
}

/* Lists */
ul, ol {
  list-style: none;
}

/* Images & Media */
img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

img {
  border-style: none;
  vertical-align: middle;
}

/* Forms */
input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
  background: transparent;
  border: none;
  outline: none;
}

button {
  cursor: pointer;
  user-select: none;
}

button:disabled,
input:disabled,
textarea:disabled,
select:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

/* Remove default button styles */
button,
[type="button"],
[type="reset"],
[type="submit"] {
  -webkit-appearance: button;
  appearance: button;
}

/* Tables */
table {
  border-collapse: collapse;
  border-spacing: 0;
  width: 100%;
}

/* Links */
a {
  color: inherit;
  text-decoration: none;
  background-color: transparent;
}

/* Code & Preformatted Text */
code,
kbd,
samp,
pre {
  font-family: var(--font-family-mono);
  font-size: 0.9em;
}

/* Selection */
::selection {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

::-moz-selection {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

/* ============================================================================
   BASE TYPOGRAPHY
   ========================================================================= */

/* Headings */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family-heading);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
  margin-bottom: var(--space-4);
  letter-spacing: var(--letter-spacing-tight);
}

h1 {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-extrabold);
  margin-bottom: var(--space-6);
}

h2 {
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--space-5);
}

h3 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--space-4);
}

h4 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-4);
}

h5 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-3);
}

h6 {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-3);
}

/* Responsive Headings */
@media (max-width: 768px) {
  h1 {
    font-size: var(--font-size-3xl);
  }
  
  h2 {
    font-size: var(--font-size-2xl);
  }
  
  h3 {
    font-size: var(--font-size-xl);
  }
}

/* Paragraphs */
p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
}

p:last-child {
  margin-bottom: 0;
}

/* Links */
a {
  color: var(--color-primary);
  transition: color var(--transition-fast) var(--transition-ease);
}

a:hover {
  color: var(--color-primary-hover);
}

a:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-border-focus);
  outline-offset: var(--focus-ring-offset);
  border-radius: var(--radius-sm);
}

/* Strong & Emphasis */
strong, b {
  font-weight: var(--font-weight-bold);
}

em, i {
  font-style: italic;
}

/* Small Text */
small {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* Blockquote */
blockquote {
  margin: var(--space-6) 0;
  padding: var(--space-4) var(--space-6);
  border-left: 4px solid var(--color-primary);
  background-color: var(--color-surface);
  font-style: italic;
  color: var(--color-text-secondary);
}

/* Code */
code {
  padding: var(--space-1) var(--space-2);
  background-color: var(--color-surface-dark);
  border-radius: var(--radius-sm);
  font-size: 0.875em;
  color: var(--color-danger);
}

pre {
  margin: var(--space-4) 0;
  padding: var(--space-4);
  background-color: var(--color-gray-900);
  color: var(--color-gray-100);
  border-radius: var(--radius-md);
  overflow-x: auto;
}

pre code {
  padding: 0;
  background: none;
  color: inherit;
}

/* Horizontal Rule */
hr {
  margin: var(--space-8) 0;
  border: 0;
  border-top: var(--border-width) solid var(--color-border);
}

/* ============================================================================
   LAYOUT UTILITIES
   ========================================================================= */

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

.container-fluid {
  width: 100%;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

.container-narrow {
  max-width: 960px;
}

.container-wide {
  max-width: 1440px;
}

/* Flex Utilities */
.flex {
  display: flex;
}

.inline-flex {
  display: inline-flex;
}

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

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

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

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

.justify-start {
  justify-content: flex-start;
}

.justify-end {
  justify-content: flex-end;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.justify-around {
  justify-content: space-around;
}

.justify-evenly {
  justify-content: space-evenly;
}

.items-start {
  align-items: flex-start;
}

.items-end {
  align-items: flex-end;
}

.items-center {
  align-items: center;
}

.items-baseline {
  align-items: baseline;
}

.items-stretch {
  align-items: stretch;
}

.flex-1 {
  flex: 1 1 0%;
}

.flex-auto {
  flex: 1 1 auto;
}

.flex-none {
  flex: none;
}

/* Grid Utilities */
.grid {
  display: grid;
  gap: var(--grid-gap);
}

.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid-cols-5 { grid-template-columns: repeat(5, minmax(0, 1fr)); }
.grid-cols-6 { grid-template-columns: repeat(6, minmax(0, 1fr)); }

@media (max-width: 1024px) {
  .grid-cols-lg-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-cols-lg-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 768px) {
  .grid-cols-md-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
  .grid-cols-md-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .grid-cols-sm-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
}

/* Gap Utilities */
.gap-0 { gap: var(--space-0); }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* Display Utilities */
.block { display: block; }
.inline-block { display: inline-block; }
.inline { display: inline; }
.hidden { display: none; }

/* Position Utilities */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

/* Text Alignment */
.text-left { text-align: left; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-justify { text-align: justify; }

/* ============================================================================
   ACCESSIBILITY
   ========================================================================= */

/* Screen Reader Only */
.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;
}

.sr-only-focusable:focus,
.sr-only-focusable:active {
  position: static;
  width: auto;
  height: auto;
  overflow: visible;
  clip: auto;
  white-space: normal;
}

/* Skip Link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  padding: var(--space-2) var(--space-4);
  text-decoration: none;
  z-index: 9999;
}

.skip-link:focus {
  top: 0;
}

/* Focus Visible */
:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-border-focus);
  outline-offset: var(--focus-ring-offset);
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  .animate-none {
    animation: none !important;
    transition: none !important;
  }
}

/* ============================================================================
   BUTTON COMPONENTS
   ========================================================================= */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-tight);
  text-align: center;
  text-decoration: none;
  white-space: nowrap;
  border: var(--border-width) solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  user-select: none;
  transition: all var(--transition-base) var(--transition-ease);
}

.btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-border-focus);
  outline-offset: var(--focus-ring-offset);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  pointer-events: none;
}

/* Button Variants */
.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse)!important;
  border-color: var(--color-primary);
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

.btn-secondary {
  background-color: var(--color-secondary);
  color: var(--color-text-inverse)!important;
  border-color: var(--color-secondary);
}

.btn-secondary:hover {
  background-color: var(--color-secondary-dark);
  border-color: var(--color-secondary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-accent {
  background-color: var(--color-accent);
  color: var(--color-text-primary);
  border-color: var(--color-accent);
  font-weight: var(--font-weight-bold);
}

.btn-accent:hover {
  background-color: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

.btn-outline:hover {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

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

.btn-ghost:hover {
  background-color: var(--color-surface);
}

.btn-danger {
  background-color: var(--color-danger);
  color: var(--color-text-inverse);
  border-color: var(--color-danger);
}

.btn-danger:hover {
  background-color: var(--color-danger-dark);
  border-color: var(--color-danger-dark);
}

.btn-success {
  background-color: var(--color-success);
  color: var(--color-text-inverse);
  border-color: var(--color-success);
}

.btn-success:hover {
  background-color: var(--color-success-dark);
  border-color: var(--color-success-dark);
}

/* Button Sizes */
.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--font-size-lg);
}

.btn-xl {
  padding: var(--space-5) var(--space-10);
  font-size: var(--font-size-xl);
}

/* Button Block */
.btn-block {
  display: flex;
  width: 100%;
}

/* Button Group */
.btn-group {
  display: inline-flex;
  gap: var(--space-2);
}

/* ============================================================================
   FORM COMPONENTS
   ========================================================================= */

/* Form Groups */
.form-group {
  margin-bottom: var(--space-4);
}

.form-label {
  display: block;
  margin-bottom: var(--space-2);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
  letter-spacing: var(--letter-spacing-wide);
  text-transform: uppercase;
}

.form-label-required::after {
  content: '*';
  color: var(--color-danger);
  margin-left: var(--space-1);
}

/* Input Styles */
.form-input,
.form-select,
.form-textarea {
  display: block;
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-background);
  background-clip: padding-box;
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast) var(--transition-ease),
              box-shadow var(--transition-fast) var(--transition-ease);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-muted);
  opacity: 1;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--color-border-focus);
  outline: 0;
  box-shadow: 0 0 0 var(--focus-ring-width) rgba(44, 95, 141, 0.2);
}

.form-input:disabled,
.form-select:disabled,
.form-textarea:disabled {
  background-color: var(--color-surface);
  opacity: 0.6;
  cursor: not-allowed;
}

/* Textarea */
.form-textarea {
  min-height: 120px;
  resize: vertical;
}

/* Select */
.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%234A5568' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-3) center;
  padding-right: var(--space-8);
}

/* Checkbox & Radio */
.form-check {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.form-check-input {
  width: 1.25rem;
  height: 1.25rem;
  flex-shrink: 0;
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast) var(--transition-ease);
}

.form-check-input[type="radio"] {
  border-radius: var(--radius-full);
}

.form-check-input:checked {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}

.form-check-input:focus {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 var(--focus-ring-width) rgba(44, 95, 141, 0.2);
}

.form-check-label {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  cursor: pointer;
}

/* Input States */
.form-input.is-valid,
.form-select.is-valid,
.form-textarea.is-valid {
  border-color: var(--color-success);
}

.form-input.is-invalid,
.form-select.is-invalid,
.form-textarea.is-invalid {
  border-color: var(--color-danger);
}

/* Form Feedback */
.form-feedback {
  display: block;
  margin-top: var(--space-2);
  font-size: var(--font-size-sm);
}

.form-feedback-valid {
  color: var(--color-success);
}

.form-feedback-invalid {
  color: var(--color-danger);
}

/* Input Group */
.input-group {
  display: flex;
  align-items: stretch;
  width: 100%;
}

.input-group .form-input {
  flex: 1;
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.input-group-append {
  display: flex;
  align-items: center;
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-surface);
  border: var(--border-width) solid var(--color-border);
  border-left: 0;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

/* ============================================================================
   CARD COMPONENT
   ========================================================================= */

.card {
  display: flex;
  flex-direction: column;
  background-color: var(--color-background);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow var(--transition-base) var(--transition-ease),
              transform var(--transition-base) var(--transition-ease);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-header {
  padding: var(--space-4) var(--space-6);
  background-color: var(--color-surface);
  border-bottom: var(--border-width) solid var(--color-border);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

.card-body {
  padding: var(--space-6);
  flex: 1;
}

.card-footer {
  padding: var(--space-4) var(--space-6);
  background-color: var(--color-surface);
  border-top: var(--border-width) solid var(--color-border);
}

.card-img-top {
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.card-title {
  margin-bottom: var(--space-3);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

.card-text {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
}

.card-text:last-child {
  margin-bottom: 0;
}

/* Card Variants */
.card-interactive {
  cursor: pointer;
  transition: all var(--transition-base) var(--transition-ease);
}

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

.card-bordered {
  border-width: var(--border-width-thick);
  border-color: var(--color-border-dark);
}

.card-elevated {
  border: none;
  box-shadow: var(--shadow-md);
}

/* ============================================================================
   BADGE COMPONENT
   ========================================================================= */

.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  line-height: 1;
  letter-spacing: var(--letter-spacing-wide);
  text-transform: uppercase;
  border-radius: var(--radius-full);
  white-space: nowrap;
}

.badge-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

.badge-secondary {
  background-color: var(--color-secondary);
  color: var(--color-text-inverse);
}

.badge-success {
  background-color: var(--color-success);
  color: var(--color-text-inverse);
}

.badge-warning {
  background-color: var(--color-warning);
  color: var(--color-text-primary);
}

.badge-danger {
  background-color: var(--color-danger);
  color: var(--color-text-inverse);
}

.badge-info {
  background-color: var(--color-info);
  color: var(--color-text-inverse);
}

.badge-outline {
  background-color: transparent;
  border: var(--border-width) solid currentColor;
}

/* ============================================================================
   ALERT COMPONENT
   ========================================================================= */

.alert {
  padding: var(--space-4) var(--space-6);
  margin-bottom: var(--space-4);
  border: var(--border-width) solid transparent;
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
}

.alert-success {
  background-color: var(--color-success-light);
  border-color: var(--color-success);
  color: var(--color-success-dark);
}

.alert-warning {
  background-color: var(--color-warning-light);
  border-color: var(--color-warning);
  color: var(--color-warning-dark);
}

.alert-danger {
  background-color: var(--color-danger-light);
  border-color: var(--color-danger);
  color: var(--color-danger-dark);
}

.alert-info {
  background-color: var(--color-info-light);
  border-color: var(--color-info);
  color: var(--color-info-dark);
}

/* ============================================================================
   SPACING UTILITIES
   ========================================================================= */

/* Margin */
.m-0 { margin: var(--space-0); }
.m-1 { margin: var(--space-1); }
.m-2 { margin: var(--space-2); }
.m-3 { margin: var(--space-3); }
.m-4 { margin: var(--space-4); }
.m-6 { margin: var(--space-6); }
.m-8 { margin: var(--space-8); }

.mt-0 { margin-top: var(--space-0); }
.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }

.mb-0 { margin-bottom: var(--space-0); }
.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.ml-auto { margin-left: auto; }
.mr-auto { margin-right: auto; }
.mx-auto { margin-left: auto; margin-right: auto; }

/* Padding */
.p-0 { padding: var(--space-0); }
.p-1 { padding: var(--space-1); }
.p-2 { padding: var(--space-2); }
.p-3 { padding: var(--space-3); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

.pt-0 { padding-top: var(--space-0); }
.pt-4 { padding-top: var(--space-4); }
.pt-6 { padding-top: var(--space-6); }
.pt-8 { padding-top: var(--space-8); }

.pb-0 { padding-bottom: var(--space-0); }
.pb-4 { padding-bottom: var(--space-4); }
.pb-6 { padding-bottom: var(--space-6); }
.pb-8 { padding-bottom: var(--space-8); }

/* ============================================================================
   UTILITY CLASSES
   ========================================================================= */

/* Width */
.w-full { width: 100%; }
.w-auto { width: auto; }

/* Height */
.h-full { height: 100%; }
.h-auto { height: auto; }

/* Text */
.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); }

.font-light { font-weight: var(--font-weight-light); }
.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); }

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

.text-color-primary { color: var(--color-primary); }
.text-color-success { color: var(--color-success); }
.text-color-warning { color: var(--color-warning); }
.text-color-danger { color: var(--color-danger); }

.uppercase { text-transform: uppercase; }
.lowercase { text-transform: lowercase; }
.capitalize { text-transform: capitalize; }

/* Background */
.bg-primary { background-color: var(--color-primary); }
.bg-secondary { background-color: var(--color-secondary); }
.bg-surface { background-color: var(--color-surface); }
.bg-white { background-color: var(--color-white); }

/* Border */
.border { border: var(--border-width) solid var(--color-border); }
.border-0 { border: none; }
.border-t { border-top: var(--border-width) solid var(--color-border); }
.border-b { border-bottom: var(--border-width) solid var(--color-border); }

.rounded { border-radius: var(--radius-base); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

/* Shadow */
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow { box-shadow: var(--shadow-base); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-none { box-shadow: none; }

/* Overflow */
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-x-auto { overflow-x: auto; }
.overflow-y-auto { overflow-y: auto; }

/* Cursor */
.cursor-pointer { cursor: pointer; }
.cursor-not-allowed { cursor: not-allowed; }

/* User Select */
.select-none { user-select: none; }
.select-text { user-select: text; }

/* Pointer Events */
.pointer-events-none { pointer-events: none; }
.pointer-events-auto { pointer-events: auto; }

/* Opacity */
.opacity-0 { opacity: 0; }
.opacity-50 { opacity: 0.5; }
.opacity-75 { opacity: 0.75; }
.opacity-100 { opacity: 1; }

/* ============================================================================
   END OF BASE.CSS
   ========================================================================= */