/* ============================================
   BASE.CSS - Industrial E-Commerce Foundation
   Polish Tools & DIY Platform
   ============================================ */

/* Variables
   ============================================ */
:root {
  /* Color Palette - Industrial Steel & Graphite */
  --color-bg: #ffffff;
  --color-bg-secondary: #f8fafc;
  --color-bg-tertiary: #f1f5f9;
  
  --color-text: #334155;
  --color-text-heading: #0f172a;
  --color-text-muted: #64748b;
  
  /* Deep Steel Blue - Primary */
  --color-primary: #1e40af;
  --color-primary-hover: #1e3a8a;
  --color-primary-subtle: #dbeafe;
  --color-primary-dark: #172554;
  
  /* Safety Orange - Energetic Accent */
  --color-accent: #ea580c;
  --color-accent-hover: #c2410c;
  --color-accent-subtle: #ffedd5;
  
  /* Status Colors */
  --color-success: #15803d;
  --color-success-subtle: #dcfce7;
  --color-warning: #ca8a04;
  --color-warning-subtle: #fef9c3;
  --color-danger: #dc2626;
  --color-danger-subtle: #fee2e2;
  
  /* Graphite Gray Spectrum */
  --gray-50: #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;
  
  /* Typography - Clean Industrial */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, monospace;
  
  --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 */
  --text-6xl: 3.75rem;   /* 60px */
  
  --leading-tight: 1.2;
  --leading-normal: 1.6;
  --leading-relaxed: 1.75;
  
  /* Spacing Scale */
  --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 */
  
  /* Radius - Subtle Industrial */
  --radius-sm: 0.25rem;  /* 4px */
  --radius-md: 0.375rem; /* 6px */
  --radius-lg: 0.5rem;   /* 8px */
  --radius-xl: 0.75rem;  /* 12px */
  
  /* Shadows - Precision Depth */
  --shadow-sm: 0 1px 2px 0 rgb(15 23 42 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(15 23 42 / 0.1), 0 2px 4px -2px rgb(15 23 42 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(15 23 42 / 0.1), 0 4px 6px -4px rgb(15 23 42 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(15 23 42 / 0.1), 0 8px 10px -6px rgb(15 23 42 / 0.1);
  --shadow-inner: inset 0 2px 4px 0 rgb(15 23 42 / 0.05);
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Layout */
  --container-max: 1400px;
  --container-padding: var(--space-4);
  --header-height: 4rem;
}

/* Reset & Normalize
   ============================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  -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;
    scroll-behavior: auto !important;
  }
}

body {
  min-height: 100vh;
  line-height: var(--leading-normal);
}

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

input, button, textarea, select {
  font: inherit;
  color: inherit;
  letter-spacing: inherit;
}

button {
  cursor: pointer;
  background: none;
  border: none;
}

a {
  text-decoration: none;
  color: inherit;
}

ul, ol {
  list-style: none;
}

/* Base Styles
   ============================================ */
body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  /* Polish diacritics support */
  font-feature-settings: "kern" 1, "liga" 1;
}

/* Typography Scale */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-text-heading);
  font-weight: 700;
  line-height: var(--leading-tight);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-4);
}

h1 { font-size: var(--text-4xl); font-weight: 800; }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); text-transform: uppercase; letter-spacing: 0.05em; }

@media (min-width: 768px) {
  h1 { font-size: var(--text-5xl); }
  h2 { font-size: var(--text-4xl); }
}

p {
  margin-bottom: var(--space-4);
  }

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

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

a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* Selection */
::selection {
  background-color: var(--color-primary-subtle);
  color: var(--color-primary-dark);
}

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

.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;
}

/* Flex Utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-start { align-items: flex-start; }
.items-center { align-items: center; }
.items-end { align-items: flex-end; }
.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* Grid Utilities */
.grid { display: grid; }
.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)); }

@media (min-width: 768px) {
  .md\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .md\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .md\:grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

/* Spacing Utilities */
.m-0 { margin: 0; }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

/* Text Utilities */
.text-sm { font-size: var(--text-sm); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }
.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }

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

/* Buttons - Industrial Precision */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  transition: all var(--transition-base);
  white-space: nowrap;
}

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

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

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

.btn--primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
  color: white;
}

.btn--secondary {
  background-color: white;
  color: var(--color-text-heading);
  border-color: var(--gray-300);
}

.btn--secondary:hover:not(:disabled) {
  background-color: var(--gray-50);
  border-color: var(--gray-400);
}

.btn--accent {
  background-color: var(--color-accent);
  color: white;
  border-color: var(--color-accent);
}

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

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

.btn--ghost:hover:not(:disabled) {
  background-color: var(--gray-100);
  color: var(--color-text-heading);
}

.btn--lg {
  padding: var(--space-4) var(--space-6);
  font-size: var(--text-base);
}

.btn--sm {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-xs);
}

/* Form Inputs */
.input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text-heading);
  background-color: white;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input:hover {
  border-color: var(--gray-400);
}

.input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-subtle);
}

.input::placeholder {
  color: var(--color-text-muted);
}

.input:disabled {
  background-color: var(--gray-100);
  cursor: not-allowed;
  opacity: 0.7;
}

/* Cards - Robust Construction */
.card {
  background-color: white;
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-sm);
  padding: var(--space-6);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

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

.card--interactive:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.card--flat {
  box-shadow: none;
  border: 1px solid var(--gray-200);
}

/* Accessibility Enhancements
   ============================================ */
@media (prefers-contrast: high) {
  :root {
    --color-primary: #0000ee;
    --color-text: #000000;
    --color-text-heading: #000000;
    --gray-300: #666666;
    --gray-200: #999999;
  }
  
  .card, .input {
    border-width: 2px;
  }
}

/* Focus visible polyfill support */
.js-focus-visible :focus:not(.focus-visible) {
  outline: none;
}

/* Print Styles */
@media print {
  *, *::before, *::after {
    background: transparent !important;
    color: black !important;
    box-shadow: none !important;
    text-shadow: none !important;
  }
  
  a, a:visited {
    text-decoration: underline;
  }
  
  .sr-only {
    display: none;
  }
}